Configuring and Troubleshooting Frame Relay
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Document ID: 16563.

  Introduction
  Before You Begin
    Conventions
    Components Used
    Background Theory
  Configuring Basic Frame Relay
    Network Diagram
    Configurations
    debug and show Commands
  Configuring Hub and Spoke Frame Relay
    Network Diagram
    Configurations
    show Commands
    Connecting from Spoke to Spoke
    Configurations
    show Commands
  Configuring Frame Relay Subinterfaces
    Point-to-Point Subinterfaces
    show Commands
    Hub and Spoke Subinterfaces
    show Commands
  Configuring Dynamic and Static Mapping for Multipoint Subinterfaces
    Network Diagram
    Configurations
    debug and show Commands
  Configuring IP Unnumbered Frame Relay
    Network Diagram
    Configurations
    show Commands
  Configuring Frame Relay Backup
    Frame Relay Backup over ISDN
    Configuration Per DCLI Backup
    Hub and Spoke with Dialer Profiles
  Configuring Frame Relay Switching
    Network Diagram.
    Configurations
    show Commands
  Configuring Frame Relay DLCI Prioritization
    Implementation Considerations
    Network Diagram..
    Configurations
    debug and show Commands
  Frame Relay Broadcast Queue.
  Traffic Shaping
  Configuring and Troubleshooting Frame Relay
    Traffic Shaping Parameters
    Generic Traffic Shaping
    Frame Relay Traffic Shaping
  Commonly Used Frame Relay Commands.
    show frame-relay pvc
    show frame-relay map
  Frame Relay and Bridging
  Frame Relay and Memory
  Troubleshooting Frame Relay
    "Serial0 is down, line protocol is down"
    "Serial0 is up, line protocol is down"
    "Serial0 is up, line protocol is up"
  Frame Relay Characteristics
    IP Split Horizon Checking
    Ping Your Own IP Address on a Multipoint Frame Relay
    The Keyword broadcast
    Reconfiguring a Subinterface
    DLCI Limitations
    IP/IPX/AT Address
    RIP and IGRP
    Keepalive
    Serial Interfaces
    OSPF and Multipoint
  Sources
  Related Information
Introduction

Frame Relay is an industry-standard, switched data link layer protocol that handles multiple virtual circuits using High-Level Data Link Control (HDLC) encapsulation between connected devices. In many cases, Frame Relay is more efficient than X.25, the protocol for which it is generally considered a replacement. The following figure illustrates a Frame Relay frame (ANSI T1.618).


Note in the above figure, Q.922 addresses, as presently defined, are two octets and contain a 10-bit data-link connection identifier (DLCI). In some networks Q.922 addresses may optionally be increased to three or four octets.

The "flag" fields delimit the beginning and end of the frame. Following the leading "flag" field are two bytes of address information. Ten bits of these two bytes make up the actual circuit ID (called the DLCI, for data-link connection identifier).

The 10-bit DLCI value is the heart of the Frame Relay header. It identifies the logical connection that is multiplexed into the physical channel. In the basic (that is, not extended by the Local Management Interface [LMI]) mode of addressing, DLCIs have local significance; that is, the end devices at two different ends of a connection may use a different DLCI to refer to that same connection.


Before You Begin

Conventions

For more information on document conventions, see the Cisco Technical Tips Conventions.


Prerequisites

For more information and definitions for the terms used in this document, please refer to the Frame Relay Glossary


Components Used

This document is not restricted to specific software and hardware versions.

The information presented in this document was created from devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If you are working in a live network, ensure that you understand the potential impact of any command before using it.


Background Theory

Frame Relay was originally conceived as a protocol for use over ISDN interfaces. Initial proposals to this effect were submitted to the International Telecommunication Union Telecommunication Standardization Sector (ITU-T) (formerly the Consultative Committee for International Telegraph and Telephone [CCITT]) in 1984. Work on Frame Relay was also undertaken in the ANSI-accredited T1S1 standards committee in the United States.

In 1990, Cisco Systems, StrataCom, Northern Telecom, and Digital Equipment Corporation formed a consortium to focus Frame Relay technology development and accelerate the introduction of inter operable Frame Relay products. They developed a specification conforming to the basic Frame Relay protocol being discussed in T1S1 and ITU-T, but extended it with features that provide additional capabilities for complex internetworking environments. These Frame Relay extensions are referred to collectively as the LMI. This is the "cisco" LMI in the router as opposed to the "ansi" or "q933a" LMI.

Frame Relay provides a packet-switching data communications capability that is used across the interface between user devices (such as routers, bridges, host machines) and network equipment (such as switching nodes). User devices are often referred to as data terminal equipment (DTE), while network equipment that interfaces to DTE is often referred to as data circuit-terminating equipment (DCE). The network providing the Frame Relay interface can be either a carrier-provided public network or a network of privately owned equipment serving a single enterprise.

Frame Relay differs significantly from X.25 in its functionality and format. In particular, Frame Relay is a more streamlined protocol, facilitating higher performance and greater efficiency.

As an interface between user and network equipment, Frame Relay provides a means for statistically multiplexing many logical data conversations (referred to as virtual circuits) over a single physical transmission link. This contrasts with systems that use only time-division-multiplexing (TDM) techniques for supporting multiple data streams. Frame Relay's statistical multiplexing provides more flexible and efficient use of available bandwidth. It can be used without TDM techniques or on top of channels provided by TDM systems.

Another important characteristic of Frame Relay is that it exploits the recent advances in wide-area network (WAN) transmission technology. Earlier WAN protocols, such as X.25, were developed when analog transmission systems and copper media were predominant. These links are much less reliable than the fiber media/digital transmission links available today. Over links such as these, link-layer protocols can forego time-consuming error correction algorithms, leaving these to be performed at higher protocol layers. Greater performance and efficiency is therefore possible without sacrificing data integrity. Frame Relay is designed with this approach in mind. It includes a cyclic redundancy check (CRC) algorithm for detecting corrupted bits (so the data can be discarded), but it does not include any protocol mechanisms for correcting bad data (for example, by retransmitting it at this level of protocol).

Another difference between Frame Relay and X.25 is the absence of explicit, per-virtual-circuit flow control in Frame Relay. Now that many upper-layer protocols are effectively executing their own flow control algorithms, the need for this functionality at the link layer has diminished. Frame Relay, therefore, does not include explicit flow control procedures that duplicate those in higher layers. Instead, very simple congestion notification mechanisms are provided to allow a network to inform a user device that the network resources are close to a congested state. This notification can alert higher-layer protocols that flow control may be needed.


Configuring Basic Frame Relay

Once you have reliable connections to the local Frame Relay switch at both ends of the permanent virtual circuit (PVC), then it is time to start planning the Frame Relay configuration. In this first example, the Local Management Interface (LMI)-type defaults to "cisco" LMI on Spicey. An interface is by default a "multipoint" interface so, frame-relay inverse-arp is on (for point-to-point, there is no Inverse ARP). IP split horizon checking is disabled by default for Frame Relay encapsulation, so routing updates come in and out the same interface. The routers learn the data-link connection identifiers (DLCIs) they need to use from the Frame Relay switch via LMI updates. The routers then Inverse ARP for the remote IP address and create a mapping of local DLCIs and their associated remote IP addresses.


Network Diagram

Configurations
  • Spicey

  • Prasit



debug and show Commands

Before issuing debug commands, please see Important Information on Debug Commands.


  • show frame-relay map

  • show frame-relay pvc

  • show frame-relay lmi

  • ping

  • show ip route

Spicey

    Spicey#show frame-relay map
    Serial0 (up): ip 3.1.3.2 dlci 140(0x8C,0x20C0), dynamic,
    broadcast,, status defined, active
    Spicey#show frame-relay pvc
    PVC Statistics for interface Serial0 (Frame Relay DTE)
    Active Inactive Deleted Static
    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0
    DLCI = 140, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0
    input pkts 83 output pkts 87 in bytes 8144
    out bytes 8408 dropped pkts 0 in FECN pkts0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 41 out bcast bytes 3652
    pvc create time 01:31:50, last time pvc status changed 01:28:28
    Spicey#show frame-relay lmi
    LMI Statistics for interface Serial0 (Frame Relay DTE) LMI TYPE = CISCO
    Invalid Unnumbered info 0 Invalid Prot Disc 0
    Invalid dummy Call Ref 0 Invalid Msg Type 0
    Invalid Status Message 0 Invalid Lock Shift 0
    Invalid Information ID 0 Invalid Report IE Len 0
    Invalid Report Request 0 Invalid Keep IE Len 0
    Num Status Enq. Sent 550 Num Status msgs Rcvd 552
    Num Update Status Rcvd 0 Num Status Timeouts 0
    Spicey#ping 123.123.123.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 123.123.123.1, timeout is 2 seconds:
!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/40 ms
    Spicey#show ip route
    Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
    i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS

    inter area
    * - candidate default, U - per-user static route, o - ODR
    P - periodic downloaded static route
    Gateway of last resort is not set
    3.0.0.0/24 is subnetted, 1 subnets
    C 3.1.3.0 is directly connected, Serial0
    124.0.0.0/24 is subnetted, 1 subnets
    C 124.124.124.0 is directly connected, Ethernet0
    R 123.0.0.0/8 [120/1] via 3.1.3.2, 00:00:08, Serial0


Prasit

    Prasit#show frame-relay map
    Serial1 (up): ip 3.1.3.1 dlci 150(0x96,0x2460), dynamic,
    broadcast,, status defined, active
    Prasit#show frame-relay pvc
    PVC Statistics for interface Serial1 (Frame Relay DTE)
    Active Inactive Deleted Static
    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 150, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial1
    input pkts 87 output pkts 83 in bytes 8408
    out bytes 8144 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 38 out bcast bytes 3464
    pvc create time 01:34:29, last time pvc status changed 01:28:05

    Prasit#show frame-relay lmi
    LMI Statistics for interface Serial1 (Frame Relay DTE) LMI TYPE = CISCO
    Invalid Unnumbered info 0 Invalid Prot Disc 0
    Invalid dummy Call Ref 0 Invalid Msg Type 0
    Invalid Status Message 0 Invalid Lock Shift 0
    Invalid Information ID 0 Invalid Report IE Len 0
    Invalid Report Request 0 Invalid Keep IE Len 0
    Num Status Enq. Sent 569 Num Status msgs Rcvd 570
    Num Update Status Rcvd 0 Num Status Timeouts 0
    Prasit#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:
!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/36 ms
    Prasit#show ip route
    Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
    i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS

    inter area
    * - candidate default, U - per-user static route, o - ODR
    P - periodic downloaded static route
    Gateway of last resort is not set
    3.0.0.0/24 is subnetted, 1 subnets
    C 3.1.3.0 is directly connected, Serial1
    R 124.0.0.0/8 [120/1] via 3.1.3.1, 00:00:19, Serial1
    123.0.0.0/24 is subnetted, 1 subnets
    C 123.123.123.0 is directly connected, Ethernet0



Configuring Hub and Spoke Frame Relay

In this example, the router learns which data-link connection identifiers (DLCIs) it uses from the Frame Relay switch and assigns them to the main interface. Then the router will Inverse ARP for the remote IP address.

Note: You will not be able to ping Prasit's serial IP address from Aton unless you explicitly add in Frame Relay maps on each end. If routing is configured correctly, traffic originating on the LANs should not have a problem. You will be able to ping if you use the Ethernet IP address as the source address in an extended ping.

When frame-relay inverse-arp is enabled, broadcast IP traffic will go out over the connection by default.



Network Diagram

Configurations
  • Spicey

  • Prasit

  • Aton




show Commands
  • show frame-relay map

  • show frame-relay pvc

  • ping < device name>

Spicey

    spicey#show frame-relay map
    Serial0 (up): ip 3.1.3.2 dlci 140(0x8C,0x20C0), dynamic,
    broadcast,, status defined, active
    Serial0 (up): ip 3.1.3.3 dlci 130(0x82,0x2020), dynamic,
    broadcast,, status defined, active
    spicey#show frame-relay pvc
    PVC Statistics for interface Serial0 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 2 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 130, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0
    input pkts 32 output pkts 40 in bytes 3370
    out bytes 3928 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 30 out bcast bytes 2888
    pvc create time 00:15:46, last time pvc status changed 00:10:42
    DLCI = 140, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0
    input pkts 282 output pkts 291 in bytes 25070
    out bytes 27876 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 223 out bcast bytes 20884
    pvc create time 02:28:36, last time pvc status changed 02:25:14

  spicey#
    spicey#ping 3.1.3.2
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 3.1.3.2, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 32/35/36 ms
    spicey#ping 3.1.3.3
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 3.1.3.3, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 32/35/36 ms


Prasit

    prasit#show frame-relay map
    Serial1 (up): ip 3.1.3.1 dlci 150(0x96,0x2460), dynamic,
    broadcast,, status defined, active
    prasit#show frame-relay pvc
    PVC Statistics for interface Serial1 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 150, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial1
    input pkts 311 output pkts 233 in bytes 28562
    out bytes 22648 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 162 out bcast bytes 15748
    pvc create time 02:31:39, last time pvc status changed 02:25:14
    prasit#ping 3.1.3.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 3.1.3.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/36 ms
    prasit#ping 3.1.3.3
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 3.1.3.3, timeout is 2 seconds:

.....
    Success rate is 0 percent (0/5)


Aton

    aton#show frame-relay map
    Serial1 (up): ip 3.1.3.1 dlci 160(0xA0,0x2800), dynamic,
    broadcast,, status defined, active
    aton#show frame-relay pvc
    PVC Statistics for interface Serial1 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0
    DLCI = 160, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial1
    input pkts 35 output pkts 32 in bytes 3758
    out bytes 3366 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 27 out bcast bytes 2846
    pvc create time 00:10:53, last time pvc status changed 00:10:53

    aton#ping 3.1.3.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 3.1.3.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 32/35/36 ms
    aton#ping 3.1.3.2
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 3.1.3.2, timeout is 2 seconds:
.....
    Success rate is 0 percent (0/5)


Connecting from Spoke to Spoke

You cannot ping from one spoke to another spoke in a hub and spoke configuration using multipoint interfaces because there is no mapping for the other spokes' IP addresses. Only the hub's address is learned via the Inverse Address Resolution Protocol (IARP). If you configure a static map using the frame-relay map command for the IP address of a remote spoke to use the local data link connection identifier (DLCI), you can ping the addresses of other spokes.




Configurations

show Commands
  • show frame-relay map

  • ping < device name>

  • show running-config

  Prasit
    prasit#show frame-relay map
    Serial1 (up): ip 3.1.3.1 dlci 150(0x96,0x2460), dynamic,
    broadcast,, status defined, active
    Serial1 (up): ip 3.1.3.3 dlci 150(0x96,0x2460), static,
    CISCO, status defined, active

    prasit#ping 3.1.3.3
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 3.1.3.3, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 68/70/80 ms
    prasit#ping 122.122.122.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 122.122.122.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 64/67/76 ms

  Aton
    aton#show running-config
    interface Ethernet0
    ip address 122.122.122.1 255.255.255.0

!
    interface Serial1
    ip address 3.1.3.3 255.255.255.0
    no ip directed-broadcast
    encapsulation frame-relay
    frame-relay map ip 3.1.3.2 160
    frame-relay interface-dlci 160
    aton#show frame-relay map
    Serial1 (up): ip 3.1.3.1 dlci 160(0xA0,0x2800), dynamic,
    broadcast,, status defined, active
    Serial1 (up): ip 3.1.3.2 dlci 160(0xA0,0x2800), static,
    CISCO, status defined, active

    aton#ping 3.1.3.2
    Type escape sequence to abort
    Sending 5, 100-byte ICMP Echos to 3.1.3.2, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 68/68/68 ms
    aton#ping 123.123.123.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 123.123.123.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 64/67/80 ms

Configuring Frame Relay Subinterfaces

Frame Relay subinterfaces provide a mechanism for supporting partially meshed Frame Relay networks. Most protocols assume transitivity on a logical network; that is, if station A can talk to station B, and station B can talk to station C, then station A should be able to talk to station C directly. Transitivity is true on LANs, but not on Frame Relay networks unless A is directly connected to C.

Additionally, certain protocols, such as AppleTalk and transparent bridging, cannot be supported on partially meshed networks because they require "split horizon" in which a packet received on an interface cannot be transmitted out the same interface even if the packet is received and transmitted on different virtual circuits.

Configuring Frame Relay subinterfaces ensures that a single physical interface is treated as multiple virtual interfaces. This capability allows us to overcome split horizon rules. Packets received on one virtual interface can now be forwarded out another virtual interface, even if they are configured on the same physical interface.

Subinterfaces address the limitations of Frame Relay networks by providing a way to subdivide a partially meshed Frame Relay network into a number of smaller, fully meshed (or point-to-point) subnetworks. Each subnetwork is assigned its own network number and appears to the protocols as if it is reachable through a separate interface. (Note that point-to-point subinterfaces can be unnumbered for use with IP, reducing the addressing burden that might otherwise result).



Point-to-Point Subinterfaces

Network Diagram


Configuration
  • Spicey

  • Prasit



show Commands
  • show frame-relay map

  • show frame-relay pvc
Spicey

    Spicey#show frame-relay map
    Serial0.1 (up): point-to-point dlci, dlci 140(0x8C,0x20C0), broadcast
    status defined, active
    Spicey#show frame-relay pvc
    PVC Statistics for interface Serial0 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 140, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0.1
    input pkts 193 output pkts 175 in bytes 20450
    out bytes 16340 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 50 out bcast bytes 3786
    pvc create time 01:11:27, last time pvc status changed 00:42:32
    Spicey#ping 123.123.123.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 123.123.123.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/36 ms


Prasit

    Prasit#show frame-relay map
    Serial1.1 (up): point-to-point dlci, dlci 150(0x96,0x2460), broadcast
    status defined, active
    Prasit#show frame-relay pvc
    PVC Statistics for interface Serial1 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0
    DLCI = 150, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE =
    Serial1.1
    input pkts 74 output pkts 89 in bytes 7210
    out bytes 10963 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 24 out bcast bytes 4203
    pvc create time 00:12:25, last time pvc status changed 00:12:25
    Prasit#ping 124.124.124.1
    Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/36 ms


Hub and Spoke Subinterfaces

The following hub and spoke sample configuration shows two point-to-point subinterfaces and uses dynamic address resolution on one remote site. Each subinterface is provided with an individual protocol address and subnetmask, and the interface-dlci command associates the subinterface with a specified data-link connection identifier (DLCI). Addresses of remote destinations for each point-to-point subinterface are not resolved since they are point-to-point and traffic must be sent to the peer at the other end. The remote end (Aton) uses Inverse ARP for its mapping and the main hub responds accordingly with the IP address of the subinterface. This occurs because Frame Relay Inverse ARP is on by default for multipoint interfaces.



Network Diagram

Configurations
  • Spicey

  • Prasit

  • Aton




show Commands
  • show frame-relay map

  • show frame-relay pvc

Spicey

    Spicey#show frame-relay map
    Serial0.2 (up): point-to-point dlci, dlci 130(0x82,0x2020), broadcast
    status defined, active
    Serial0.1 (up): point-to-point dlci, dlci 140(0x8C,0x20C0), broadcast
    status defined, active
    Spicey#show frame-relay pvc
    PVC Statistics for interface Serial0 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 2 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 130, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0.2
    input pkts 11 output pkts 22 in bytes 1080
    out bytes 5128 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 17 out bcast bytes 4608
    pvc create time 00:06:36, last time pvc status changed 00:06:36
    DLCI = 140, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0.1
    input pkts 33 output pkts 28 in bytes 3967
    out bytes 5445 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 17 out bcast bytes 4608
    pvc create time 00:06:38, last time pvc status changed 00:06:38
    Spicey#ping 122.122.122.1

    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 122.122.122.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 32/35/36 ms
    Spicey#ping 123.123.123.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 123.123.123.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/36 ms


Prasit

    Prasit#show frame-relay map
    Serial1.1 (up): point-to-point dlci, dlci 150(0x96,0x2460), broadcast
    status defined, active
    Prasit#show frame-relay pvc
    PVC Statistics for interface Serial1 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 150, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE =
    Serial1.1
    input pkts 45 output pkts 48 in bytes 8632
    out bytes 6661 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 31 out bcast bytes 5573
    pvc create time 00:12:16, last time pvc status changed 00:06:23
    Prasit#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/36 ms


Aton

    Aton#show frame-relay map
    Serial1 (up): ip 3.1.3.1 dlci 160(0xA0,0x2800), dynamic,
    broadcast,, status defined, active
    Aton#show frame-relay pvc
    PVC Statistics for interface Serial1 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 160, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial1
    input pkts 699 output pkts 634 in bytes 81290
    out bytes 67008 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0

    out bcast pkts 528 out bcast bytes 56074
    pvc create time 05:46:14, last time pvc status changed 00:05:57
    Aton#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/36 ms


Configuring Dynamic and Static Mapping for Multipoint Subinterfaces

Dynamic address mapping uses Frame Relay Inverse ARP to request the next hop protocol address for a specific connection, given a data-link connection identifier (DLCI). Responses to Inverse ARP requests are entered in an address-to-DLCI mapping table on the router or access server; the table is then used to supply the next hop protocol address or the DLCI for outgoing traffic.

Since the physical interface is now configured as multiple subinterfaces, you must provide information that distinguishes a subinterface from the physical interface and associates a specific subinterface with a specific DLCI.

Inverse ARP is enabled by default for all protocols it supports, but can be disabled for specific protocol-DLCI pairs. As a result, you can use dynamic mapping for some protocols and static mapping for other protocols on the same DLCI. You can explicitly disable Inverse ARP for a protocol-DLCI pair if you know the protocol is not supported on the other end of the connection. Because Inverse ARP is enabled by default for all protocols that it supports, no additional command is required to configure dynamic address mapping on a subinterface.

A static map links a specified next hop protocol address to a specified DLCI. Static mapping removes the need for Inverse ARP requests; when you supply a static map, Inverse ARP is automatically disabled for the specified protocol on the specified DLCI. You must use static mapping if the router at the other end either does not support Inverse ARP at all or does not support Inverse ARP for a specific protocol that you want to use over Frame Relay.


Network Diagram

We've already seen how to configure a Cisco router to do Inverse ARP. The following example shows how to configure static maps in case you need them for multipoint interfaces or subinterfaces:



Configurations
  • Aton

  • Spicey

  • Prasit




debug and show Commands
  • show frame-relay map>

  • show frame-relay pvc
Aton

    Aton#show frame-relay map
    Serial1.1 (up): ip 4.0.1.1 dlci 160(0xA0,0x2800), static, broadcast,
    CISCO, status defined, active
    Aton#show frame-relay pvc
    PVC Statistics for interface Serial1 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 160, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE =
    Serial1.1
    input pkts 16 output pkts 9 in bytes 3342
    out bytes 450 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 9 out bcast bytes 450
    pvc create time 00:10:02, last time pvc status changed 00:10:02
    Aton#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!!!!!     Success rate is 100 percent (5/5), round-trip min/avg/max = 32/35/36 ms


Spicey

    Spicey#show frame-relay map
    Serial0 (up): ip 4.0.1.2 dlci 140(0x8C,0x20C0), static, broadcast,
    CISCO, status defined, active
    Serial0 (up): ip 4.0.1.3 dlci 130(0x82,0x2020), static, broadcast,
    CISCO, status defined, active
    Spicey#show frame-relay pvc
    PVC Statistics for interface Serial0 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 2 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 130, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0
    input pkts 9 output pkts 48 in bytes 434
    out bytes 11045 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 48 out bcast bytes 11045
    pvc create time 00:36:25, last time pvc status changed 00:36:15
    DLCI = 140, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0
    input pkts 17 output pkts 26 in bytes 1390
    out bytes 4195 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0

    out bcast pkts 16 out bcast bytes 3155
    pvc create time 00:08:39, last time pvc status changed 00:08:39
    Spicey#ping 122.122.122.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 122.122.122.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/40 ms
    Spicey#ping 123.123.123.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 123.123.123.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 32/35/36


Prasit

    Prasit#show frame-relay map
    Serial1.1 (up): ip 4.0.1.1 dlci 150(0x96,0x2460), static,
    broadcast,
    CISCO, status defined, active
    Prasit#show frame-relay pvc
    PVC Statistics for interface Serial1 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 150, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial1.1
    input pkts 28 output pkts 19 in bytes 4753
    out bytes 1490 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 9 out bcast bytes 450
    pvc create time 00:11:00, last time pvc status changed 00:11:00
    Prasit#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/36 ms
    For more information on these commands, please see Frame Relay Commands.

Configuring IP Unnumbered Frame Relay

If you do not have the IP address space to use many subinterfaces, you can use IP unnumbered on each subinterface. If this is the case, you need to use static routes or dynamic routing so that your traffic is routed as usual, and you must use point-to-point subinterfaces.


Network Diagram

The example below illustrates this:



Configurations
  • Spicey

  • Prasit



show Commands
  • show frame-relay map

  • show frame-relay pvc
Spicey

    Spicey#show frame-relay map
    Serial0.1 (up): point-to-point dlci, dlci 140(0x8C,0x20C0), broadcast
    status defined, active
    Spicey#show frame-relay pvc
    PVC Statistics for interface Serial0 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 140, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE =
    Serial0.1
    input pkts 23 output pkts 24 in bytes 3391
    out bytes 4952 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 14 out bcast bytes 3912
    pvc create time 00:04:47, last time pvc status changed 00:04:47

    Spicey#show ip route
    Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
    i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS

    inter area
    * - candidate default, U - per-user static route, o - ODR
    P - periodic downloaded static route
    Gateway of last resort is not set
    124.0.0.0/24 is subnetted, 1 subnets
    C 124.124.124.0 is directly connected, Ethernet0v     123.0.0.0/8 is variably subnetted, 2 subnets, 2 masksv     I 123.0.0.0/8 [100/8576] via 123.123.123.1, 00:01:11, Serial0.1
    I 123.123.123.0/32 [100/8576] via 123.123.123.1, 00:01:11,

    Serial0.1
    Spicey#ping 123.123.123.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 123.123.123.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/36 ms


Prasit

    Prasit#show frame-relay map
    Serial1.1 (up): point-to-point dlci, dlci 150(0x96,0x2460), broadcast
    status defined, active
    Prasit#show frame-relay pvc
    PVC Statistics for interface Serial1 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 150, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE =

    Serial1.1
    input pkts 24 output pkts 52 in bytes 4952
    out bytes 10892 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 41 out bcast bytes 9788
    pvc create time 00:10:54, last time pvc status changed 00:03:51

    Prasit#show ip route
    Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
    i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS

    inter area
    * - candidate default, U - per-user static route, o - ODR
    P - periodic downloaded static route
    Gateway of last resort is not set
    124.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
    I 124.0.0.0/8 [100/8576] via 124.124.124.1, 00:00:18, Serial1.1
    I 124.124.124.0/32 [100/8576] via 124.124.124.1, 00:00:18,

    Serial1.1
    123.0.0.0/24 is subnetted, 1 subnets
    C 123.123.123.0 is directly connected, Ethernet0
    Prasit#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/120/436 ms


Frame Relay Backup over ISDN

You may want to back up Frame Relay circuits using ISDN. There are several ways to do this. The first, and probably the best, is to use floating static routes that route traffic to a Basic Rate Interface (BRI) IP address and use an appropriate routing metric. You can also use a backup interface on the main interface or on a per-data-link connection identifier (DLCI) basis. It may not help much to back up the main interface because you could lose permanent virtual circuits (PVCs) without the main interface going down. Remember, the protocol is being exchanged with the local Frame Relay switch, not the remote router.



Configurations
  • Router 1

  • Router 2



show Commands

To verify if the ISDN is working, use the following debug commands. Before issuing debug commands, please see Important Information on Debug Commands.


  • debug isdn q931

  • debug ppp neg

  • debug ppp auth

Try to make an ISDN call from the calling side to the central side without the backup commands. If this is successful, add the backup commands to the calling side.

Note: To test the backup, do not use the shutdown command on the serial interface but emulate a real serial line problem by pulling out the cable from the serial line.


Network Diagram

Configurations
  • Spicey

  • Prasit



show Commands
  • show frame-relay map
  • show ip route

  • show isdn history

  • show isdn status

  • show interface bri 0

  • how isdn active

Spicey

    Spicey#show frame-relay map
    Serial0.2 (up): point-to-point dlci, dlci 130(0x82,0x2020), broadcast
    status defined, active
    Serial0.1 (up): point-to-point dlci, dlci 140(0x8C,0x20C0), broadcast
    status defined, active
    Spicey#show ip route
    Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
    i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS

    inter area
    * - candidate default, U - per-user static route, o - ODR
    P - periodic downloaded static route
    Gateway of last resort is not set
    3.0.0.0/24 is subnetted, 2 subnets C
    3.1.3.0 is directly connected, Serial0.2 C
    3.1.6.0 is directly connected, BRI0
    4.0.0.0/24 is subnetted, 1 subnets C
    4.0.1.0 is directly connected, Serial0.1
    124.0.0.0/24 is subnetted, 1 subnets C
    124.124.124.0 is directly connected, Ethernet0
    123.0.0.0/8 is variably subnetted, 2 subnets, 2 masks I
    123.0.0.0/8 [100/8576] via 4.0.1.2, 00:00:00, Serial0.1 S
    123.123.123.0/24 [250/0] via 3.1.6.2 I
    122.0.0.0/8 [100/8576] via 3.1.3.3, 00:00:37, Serial0.2

    Spicey#
    *Mar 1 00:59:12.527: %LINK-3-UPDOWN: Interface BRI0:1, changed state to up
    *Mar 1 00:59:13.983: %LINEPROTO-5-UPDOWN: Line protocol on Interface
    BRI0:1, changed state to up
    *Mar 1 00:59:18.547: %ISDN-6-CONNECT: Interface BRI0:1 is now connected to 6105 Prasit
    Spicey#show isdn history

--------------------------------------------------------------------------------     ISDN CALL HISTORY

--------------------------------------------------------------------------------     Call History contains all active calls, and a maximum of 100 inactive calls.
    Inactive call data will be retained for a maximum of 15 minutes.
--------------------------------------------------------------------------------     Call Calling Called Remote Seconds Seconds Seconds

    Charges
    Type Number Number Name Used Left Idle Units/Currency

--------------------------------------------------------------------------------     In 6105 6106 Prasit 31 90 29

--------------------------------------------------------------------------------     Spicey#
    *Mar 1 01:01:14.547: %ISDN-6-DISCONNECT: Interface BRI0:1 disconnected
    from 6105 Prasit, call lasted 122 seconds
    *Mar 1 01:01:14.663: %LINK-3-UPDOWN: Interface BRI0:1, changed state to down
  *Mar 1 01:01:15.663: %LINEPROTO-5-UPDOWN: Line protocol on Interface
  BRI0:1, changed state to down


Prasit

    Prasit#show frame-relay map
    Serial1.1 (up): point-to-point dlci, dlci 150(0x96,0x2460), broadcast
    status defined, active
    Prasit#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/40 ms
    Prasit#show ip route
    Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
    i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS

    inter area
    * - candidate default, U - per-user static route, o - ODR
    P - periodic downloaded static route
    Gateway of last resort is not set
    I 3.0.0.0/8 [100/10476] via 4.0.1.1, 00:00:55, Serial1.1
    4.0.0.0/24 is subnetted, 1 subnets
    C 4.0.1.0 is directly connected, Serial1.1
    124.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
    S 124.124.124.0/24 [250/0] via 3.1.6.1
    I 124.0.0.0/8 [100/8576] via 4.0.1.1, 00:00:55, Serial1.1
    123.0.0.0/24 is subnetted, 1 subnets
    C 123.123.123.0 is directly connected, Ethernet0
    I 122.0.0.0/8 [100/10576] via 4.0.1.1, 00:00:55, Serial1.1
    The serial line goes down.

  Prasit#
    *Mar 1 01:23:50.531: %LINK-3-UPDOWN: Interface Serial1, changed state to down
    *Mar 1 01:23:51.531: %LINEPROTO-5-UPDOWN: Line protocol on Interface
    Serial1, changed state to down
    *Mar 1 01:23:53.775: %LINK-3-UPDOWN: Interface BRI0:1, changed state to down
    *Mar 1 01:23:53.791: %LINK-3-UPDOWN: Interface BRI0:2, changed state to down
    *Mar 1 01:23:53.827: %LINK-3-UPDOWN: Interface BRI0, changed state to up
    *Mar 1 01:23:57.931: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI 64 changed to up

    Prasit#show ip route
    Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF,IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
    i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS

    inter area
    * - candidate default, U - per-user static route, o - ODR
    P - periodic downloaded static route
    Gateway of last resort is not set
    3.0.0.0/24 is subnetted, 1 subnets
    C 3.1.6.0 is directly connected, BRI0
    124.0.0.0/24 is subnetted, 1 subnets
    S 124.124.124.0 [250/0] via 3.1.6.1
    123.0.0.0/24 is subnetted, 1 subnets
    C 123.123.123.0 is directly connected, Ethernet0
    Prasit#show isdn status
    Global ISDN Switchtype = basic-net3

    ISDN BRI0 interface
    dsl 0, interface ISDN Switchtype = basic-net3
    Layer 1 Status:

    ACTIVE
    Layer 2 Status:
    TEI = 64, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED
    Layer 3 Status:
    0 Active Layer 3 Call(s)
    Active dsl 0 CCBs = 0
    The Free Channel Mask: 0x80000003
    Total Allocated ISDN CCBs = 0
    Prasit#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!     *Mar 1 01:25:47.383: %LINK-3-UPDOWN: Interface BRI0:1, changed state to up!!!
    Success rate is 80 percent (4/5), round-trip min/avg/max = 36/36/36 ms

    Prasit#
    Gateway of last resort is not set
    I 3.0.0.0/8 [100/10476] via 4.0.1.1, 00:00:55, Serial1.1
    4.0.0.0/24 is subnetted, 1 subnets
    C 4.0.1.0 is directly connected, Serial1.1
    124.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
    S 124.124.124.0/24 [250/0] via 3.1.6.1
    I 124.0.0.0/8 [100/8576] via 4.0.1.1, 00:00:55, Serial1.1
    123.0.0.0/24 is subnetted, 1 subnets
    C 123.123.123.0 is directly connected, Ethernet0
    I 122.0.0.0/8 [100/10576] via 4.0.1.1, 00:00:55, Serial1.1

  The serial line goes down.
    Prasit#
    *Mar 1 01:23:50.531: %LINK-3-UPDOWN: Interface Serial1, changed state to down
    *Mar 1 01:23:51.531: %LINEPROTO-5-UPDOWN: Line protocol on Interface
    Serial1, changed state to down
    *Mar 1 01:23:53.775: %LINK-3-UPDOWN: Interface BRI0:1, changed state to down
    *Mar 1 01:23:53.791: %LINK-3-UPDOWN: Interface BRI0:2, changed state to down
    *Mar 1 01:23:53.827: %LINK-3-UPDOWN: Interface BRI0, changed state to up
    *Mar 1 01:23:57.931: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI 64 changed to up

    Prasit#show ip route
    Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF,IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
    i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS

    inter area
    * - candidate default, U - per-user static route, o - ODR
    P - periodic downloaded static route
    Gateway of last resort is not set
    3.0.0.0/24 is subnetted, 1 subnets
    C 3.1.6.0 is directly connected, BRI0
    124.0.0.0/24 is subnetted, 1 subnets
    S 124.124.124.0 [250/0] via 3.1.6.1
    123.0.0.0/24 is subnetted, 1 subnets
    C 123.123.123.0 is directly connected, Ethernet0
    Prasit#show isdn status
    Global ISDN Switchtype = basic-net3
    ISDN BRI0 interface
    dsl 0, interface ISDN Switchtype = basic-net3

    Layer 1 Status:
    ACTIVE
    Layer 2 Status:
    TEI = 64, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED
    Layer 3 Status:
    0 Active Layer 3 Call(s)
    Active dsl 0 CCBs = 0
    The Free Channel Mask: 0x80000003
    Total Allocated ISDN CCBs = 0
    Prasit#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!     *Mar 1 01:25:47.383: %LINK-3-UPDOWN: Interface BRI0:1, changed state to up!!!
    Success rate is 80 percent (4/5), round-trip min/avg/max = 36/36/36 ms

    Prasit#
    Total Allocated ISDN CCBs = 0
    Prasit#show interface bri 0
    BRI0 is standby mode, line protocol is down
    Hardware is BRI
    Internet address is 3.1.6.2/24
    MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec,
    reliability 255/255, txload 1/255, rxload 1/255
    Encapsulation PPP, loopback not set
    Last input 00:01:00, output 00:01:00, output hang never
    Last clearing of "show interface" counters 01:28:16
    Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
    Queueing strategy: weighted fair
    Output queue: 0/1000/64/0 (size/max total/threshold/drops)
    Conversations 0/1/16 (active/max active/max total)
    Reserved Conversations 0/0 (allocated/max allocated)
    5 minute input rate 0 bits/sec, 0 packets/sec
    5 minute output rate 0 bits/sec, 0 packets/sec
    128 packets input, 601 bytes, 0 no buffer
    Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
    0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
    132 packets output, 687 bytes, 0 underruns
    0 output errors, 0 collisions, 10 interface resets
    0 output buffer failures, 0 output buffers swapped out
    14 carrier transitions
    Prasit#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/36 ms


Hub and Spoke with Dialer Profiles

Here is an example of a hub and spoke per DLCI backup configuration. The spoke routers are calling the hub router. As you can see, we allow only one B channel per side by using the max-link option on the dialer pool on the hub side.

Note: Backup load is not supported on subinterfaces. As we do not track traffic levels on subinterfaces, no load is calculated.


Network Diagram

Configurations
  • Aton

  • Spicey

  • Prasit




show Commands
  • show frame-relay map

  • show ip route

  • show frame map

  • show frame-relay pvc
Aton

    Aton#show frame-relay map
    Serial1.1 (up): point-to-point dlci, dlci 160(0xA0,0x2800), broadcast
    status defined, active
    Aton#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/36 ms
    Aton#show ip route
    Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
    i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default
    U - per-user static route, o - ODR, P - periodic downloaded static route
    T - traffic engineered route
    Gateway of last resort is not set
    I 155.155.0.0/16 [100/182571] via 3.1.3.1, Serial1.1
    3.0.0.0/24 is subnetted, 1 subnets
    C 3.1.3.0 is directly connected, Serial1.1
    I 4.0.0.0/8 [100/10476] via 3.1.3.1, Serial1.1
    I 160.160.0.0/16 [100/182571] via 3.1.3.1, Serial1.1
    124.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
    S 124.124.124.0/24 [250/0] via 155.155.155.2
    I 124.0.0.0/8 [100/8576] via 3.1.3.1, Serial1.1
    I 123.0.0.0/8 [100/10576] via 3.1.3.1, Serial1.1
    122.0.0.0/24 is subnetted, 1 subnets
    C 122.122.122.0 is directly connected, Ethernet0

    Aton#
    Serial 1 is going down.
    Aton#
    01:16:33: %LINK-3-UPDOWN: Interface Serial1, changed state to down
    01:16:34: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1,
    changed state to down
    01:16:37: %LINK-3-UPDOWN: Interface BRI0:1, changed state to down
    01:16:37: %LINK-3-UPDOWN: Interface BRI0:2, changed state to down
    01:16:37: %LINK-3-UPDOWN: Interface BRI0, changed state to up
    01:16:41: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI 64 changed to up

    Aton#show ip route
    Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
    i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default
      U - per-user static route, o - ODR, P - periodic downloaded static route
    T - traffic engineered route
    Gateway of last resort is not set     155.155.0.0/24 is subnetted, 1 subnets
    C 155.155.155.0 is directly connected, BRI0
    124.0.0.0/24 is subnetted, 1 subnets
    S 124.124.124.0 [250/0] via 155.155.155.2
    122.0.0.0/24 is subnetted, 1 subnets
    C 122.122.122.0 is directly connected, Ethernet0
    Aton#ping 124.124.124.1

    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:
    01:21:33: %LINK-3-UPDOWN: Interface BRI0:1, changed state to up.!!!!
    Success rate is 80 percent (4/5), round-trip min/avg/max = 36/36/36 ms

    Aton#
    01:21:34: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1,
    changed state to up

    01:21:39: %ISDN-6-CONNECT: Interface BRI0:1 is now connected to 6106

  Spicey
    Aton#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 32/123/296 ms
    Aton#
    Serial 1 becomes active again
    Aton#
    01:24:02: %ISDN-6-DISCONNECT: Interface BRI0:1 disconnected from 6106
    Spicey, call lasted 149 seconds
    01:24:02: %LINK-3-UPDOWN: Interface BRI0:1, changed state to down
    01:24:03: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1,
    ;changed state to down
    Aton#show frame map
    Serial1.1 (down): point-to-point dlci, dlci 160(0xA0,0x2800), broadcast
    status deleted

    Aton#
    01:26:35: %LINK-3-UPDOWN: Interface Serial1, changed state to up
    01:26:36: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1,
    changed state to up
    01:26:56: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BRI0, TEI 64 changed
to down

    01:26:56: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0, TEI 64 changed
to down

    01:26:56: %LINK-5-CHANGED: Interface BRI0, changed state to standby mode
    01:26:56: %LINK-3-UPDOWN: Interface BRI0:1, changed state to down
    01:26:56: %LINK-3-UPDOWN: Interface BRI0:2, changed state to down
    Aton#show frame map
    Serial1.1 (up): point-to-point dlci, dlci 160(0xA0,0x2800), broadcast status defined, active

    Aton#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:
!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/36 ms
    Aton#ping 124.124.124.1
    Aton#show frame-relay pvc
    PVC Statistics for interface Serial1 (Frame Relay DTE)
    Active Inactive Deleted Static
v     Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 160, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE =
    Serial1.1
    input pkts 60 output pkts 69 in bytes 9694
    out bytes 10811 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 44 out bcast bytes 7565
    pvc create time 01:28:35, last time pvc status changed 00:02:19


Spicey

    Spicey#show frame-relay map
    Serial0.1 (up): point-to-point dlci, dlci 140(0x8C,0x20C0), broadcast
    status defined, active
    Serial0.2 (up): point-to-point dlci, dlci 130(0x82,0x2020), broadcast
    status defined, active
    Spicey#ping 122.122.122.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 122.122.122.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 32/35/36 ms
    Spicey#ping 123.123.123.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 123.123.123.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/36 ms
    Spicey#show ip route
    Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
    i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS

    inter area
    * - candidate default, U - per-user static route, o - ODR
    P - periodic downloaded static route
    Gateway of last resort is not set
    155.155.0.0/24 is subnetted, 1 subnets
    C 155.155.155.0 is directly connected, Dialer2
    3.0.0.0/24 is subnetted, 1 subnets
    C 3.1.3.0 is directly connected, Serial0.2
    4.0.0.0/24 is subnetted, 1 subnets
    C 4.0.1.0 is directly connected, Serial0.1
    160.160.0.0/24 is subnetted, 1 subnets
    C 160.160.160.0 is directly connected, Dialer1
    124.0.0.0/24 is subnetted, 1 subnets
    C 124.124.124.0 is directly connected, Ethernet0
    I 123.0.0.0/8 [100/8576] via 4.0.1.2, 00:00:55, Serial0.1
    I 122.0.0.0/8 [100/8576] via 3.1.3.3, 00:00:35, Serial0.2
    Both serial lines from the calling sides are going down.

    Spicey#
    *Mar 1 01:21:30.171: %LINK-3-UPDOWN: Interface BRI0:1, changed state toup
    *Mar 1 01:21:30.627: %DIALER-6-BIND: Interface BR0:1 bound to profile Di2
    *Mar 1 01:21:31.647: %LINEPROTO-5-UPDOWN: Line protocol on Interface
    BRI0:1, changed state to up
    *Mar 1 01:21:36.191: %ISDN-6-CONNECT: Interface BRI0:1 is now connected to 6104 Aton

    *Mar 1 01:21:40.923: %LINK-3-UPDOWN: Interface BRI0:2, changed state to up
    *Mar 1 01:21:41.359: %DIALER-6-BIND: Interface BR0:2 bound to profile Di1
    *Mar 1 01:21:42.383: %LINEPROTO-5-UPDOWN: Line protocol on Interface
    BRI0:2, changed state to up
    *Mar 1 01:21:46.943: %ISDN-6-CONNECT: Interface BRI0:2 is now connected to 6105 Prasit

      *Mar 1 01:23:59.819: %DIALER-6-UNBIND: Interface BR0:1 unbound from profile Di2

    *Mar 1 01:23:59.831: %ISDN-6-DISCONNECT: Interface BRI0:1 disconnected from 6104 Aton, call lasted 149 seconds

    *Mar 1 01:23:59.927: %LINK-3-UPDOWN: Interface BRI0:1, changed state to down
    *Mar 1 01:24:00.923: %LINEPROTO-5-UPDOWN: Line protocol on Interface
    BRI0:1, changed state to down
    *Mar 1 01:24:03.015: %DIALER-6-UNBIND: Interface BR0:2 unbound from profile Di1

    *Mar 1 01:24:03.023: %ISDN-6-DISCONNECT: Interface BRI0:2 disconnected from 6105 Prasit, call lasted 142 seconds

    *Mar 1 01:24:03.107: %LINK-3-UPDOWN: Interface BRI0:2, changed state to down
    *Mar 1 01:24:04.107: %LINEPROTO-5-UPDOWN: Line protocol on Interface
    BRI0:2, changed state to down
    Spicey#show frame map
    Serial0.1 (down): point-to-point dlci, dlci 140(0x8C,0x20C0), broadcast status defined, inactive

    Serial0.2 (down): point-to-point dlci, dlci 130(0x82,0x2020), broadcast status defined, inactive

  Spicey#
    Both serial lines are available again.
    Spicey#show frame pvc
    PVC Statistics for interface Serial0 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 2 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 130, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0.2

    input pkts 54 output pkts 61 in bytes 7014
    out bytes 9975 dropped pkts 3 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 40 out bcast bytes 7803
    pvc create time 01:28:14, last time pvc status changed 00:02:38
    DLCI = 140, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0.1
    input pkts 56 output pkts 60 in bytes 7604
    out bytes 10114 dropped pkts 2 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 39 out bcast bytes 7928
    pvc create time 01:28:15, last time pvc status changed 00:02:29


Prasit

    Prasit#show frame-relay map
    Serial1.1 (up): point-to-point dlci, dlci 150(0x96,0x2460), broadcast status defined, active

    Prasit#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/40 ms
    Prasit#show ip route
    Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
        E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
    i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS
    inter area
    * - candidate default, U - per-user static route, o - ODR
    P - periodic downloaded static route
    Gateway of last resort is not set
    I 155.155.0.0/16 [100/182571] via 4.0.1.1, 00:00:41, Serial1.1
    I 3.0.0.0/8 [100/10476] via 4.0.1.1, 00:00:41, Serial1.1
    4.0.0.0/24 is subnetted, 1 subnets
    C 4.0.1.0 is directly connected, Serial1.1
    I 160.160.0.0/16 [100/182571] via 4.0.1.1, 00:00:41, Serial1.1
    124.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
    S 124.124.124.0/24 [250/0] via 160.160.160.1
    I 124.0.0.0/8 [100/8576] via 4.0.1.1, 00:00:41, Serial1.1
    123.0.0.0/24 is subnetted, 1 subnets
    C 123.123.123.0 is directly connected, Ethernet0
    I 122.0.0.0/8 [100/10576] via 4.0.1.1, 00:00:42, Serial1.1

    Prasit#
    Serial 1 goes down.
    Prasit#
    *Mar 1 01:16:08.287: %LINK-3-UPDOWN: Interface Serial1, changed state to down
    *Mar 1 01:16:09.287: %LINEPROTO-5-UPDOWN: Line protocol on Interface
    Serial1, changed state to down
    *Mar 1 01:16:11.803: %LINK-3-UPDOWN: Interface BRI0:1, changed state to down
    *Mar 1 01:16:11.819: %LINK-3-UPDOWN: Interface BRI0:2, changed state to down
    *Mar 1 01:16:11.855: %LINK-3-UPDOWN: Interface BRI0, changed state to up
    *Mar 1 01:16:15.967: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI

    64 changed to up
    Prasit#show ip route
    Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
    i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS

    inter area
    * - candidate default, U - per-user static route, o - ODR
    P - periodic downloaded static route
    Gateway of last resort is not set
    160.160.0.0/24 is subnetted, 1 subnets
    C 160.160.160.0 is directly connected, BRI0
    124.0.0.0/24 is subnetted, 1 subnets
    S 124.124.124.0 [250/0] via 160.160.160.1
    123.0.0.0/24 is subnetted, 1 subnets
    C 123.123.123.0 is directly connected, Ethernet0
    Prasit#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:
    *Mar 1 01:21:38.967: %LINK-3-UPDOWN: Interface BRI0:1, changed state to up.!!!!

    Success rate is 80 percent (4/5), round-trip min/avg/max = 36/36/36 ms

    Prasit#
    *Mar 1 01:21:40.063: %LINEPROTO-5-UPDOWN: Line protocol on Interface
    BRI0:1, changed state to up
    *Mar 1 01:21:44.991: %ISDN-6-CONNECT: Interface BRI0:1 is now connected to 6106 Spicey

    Prasit#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/36 ms
    Prasit#
    Serial 1 becomes active again.
    Prasit#
    *Mar 1 01:26:40.579: %LINK-3-UPDOWN: Interface Serial1, changed state to up
    *Mar 1 01:26:41.579: %LINEPROTO-5-UPDOWN: Line protocol on Interface
    Serial1, changed state to up
    *Mar 1 01:27:01.051: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BRI0, TEI 64 changed to down

    *Mar 1 01:27:01.055: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0, TEI 64 changed to down
    *Mar 1 01:27:01.363: %LINK-5-CHANGED: Interface BRI0, changed state to standby mode
    *Mar 1 01:27:01.379: %LINK-3-UPDOWN: Interface BRI0:1, changed state to down
    *Mar 1 01:27:01.395: %LINK-3-UPDOWN: Interface BRI0:2, changed state to down
    Prasit#show frame map
    Serial1.1 (up): point-to-point dlci, dlci 150(0x96,0x2460), broadcast
    status defined, active
    Prasit#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/116/432 ms
    Prasit#show frame-relay pvc
    PVC Statistics for interface Serial1 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 150, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial1.1

    input pkts 58 output pkts 66 in bytes 9727
    out bytes 10022 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 46 out bcast bytes 7942
    pvc create time 01:27:37, last time pvc status changed 00:01:59


Configuring Frame Relay Switching

Frame Relay switching is a means of switching packets based on the data-link connection identifier (DLCI).

We can look on this as the Frame Relay equivalent of a Media Access Control (MAC) address. You perform switching by configuring your Cisco router or access server into a Frame Relay network. There are two parts to a Frame Relay network:

  • Frame Relay data terminal equipment (DTE) - the router or access server.

  • Frame Relay data circuit-terminating equipment (DCE) switch.

Note: In Cisco IOS Software release 12.1(2)T and later, the frame route command has been replaced by the connectcommand.

Let's look at a sample configuration. In the configuration below, we are using the router America as a Frame Relay switch. We are using Spicey as a hub router and Prasit and Aton as spoke routers. We have connected them as follows:


  • Prasit serial 1 (s1) DTE is connected to America serial 1/4 (s1/4) DCE.

  • Spicey serial 0 (s0) DTE is connected to America serial 1/5 (s1/5) DCE

  • Aton serial 1 (s1) DTE is connected to America serial 3/4 (s3/4) DCE.
Network Diagram

This document is based on the following configuration:



Configurations
  • Spicey

  • Prasit

  • Aton

  • America





show Commands

Use the following show commands to test that your network is operating properly:


  • show frame-relay map

  • show frame-relay pvc

The output shown below is a result of entering these commands on the devices we are using in this sample configuration.



Spicey

    Spicey#show frame-relay map
    Serial0 (up): ip 3.1.3.2 dlci 140(0x8C,0x20C0), dynamic,
    broadcast,, status defined, active
    Serial0 (up): ip 3.1.3.3 dlci 130(0x82,0x2020), dynamic,
    broadcast,, status defined, active
    Spicey#show frame-relay pvc
    PVC Statistics for interface Serial0 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 2 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 130, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0
    input pkts 32 output pkts 40 in bytes 3370
    out bytes 3928 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 30 out bcast bytes 2888
    pvc create time 00:15:46, last time pvc status changed 00:10:42
    DLCI = 140, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0
    input pkts 282 output pkts 291 in bytes 25070
    out bytes 27876 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 223 out bcast bytes 20884
    pvc create time 02:28:36, last time pvc status changed 02:25:14


Prasit

    Prasit#show frame-relay map
    Serial1 (up): ip 3.1.3.1 dlci 150(0x96,0x2460), dynamic,
    broadcast,, status defined, active
    Prasit#show frame-relay pvc
    PVC Statistics for interface Serial1 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0

    DLCI = 150, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial1
    input pkts 311 output pkts 233 in bytes 28562
    out bytes 22648 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 162 out bcast bytes 15748
    pvc create time 02:31:39, last time pvc status changed 02:25:14


Aton

    Aton#show frame-relay map
    Serial1 (up): ip 3.1.3.1 dlci 160(0xA0,0x2800), dynamic, broadcast, status defined, active
    Aton#show frame-relay pvc
    PVC Statistics for interface Serial1 (Frame Relay DTE)
  Active Inactive Deleted Static

    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 160, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial
    input pkts 35 output pkts 32 in bytes 3758
    out bytes 3366 dropped pkts 0 in FECN pkt 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 27 out bcast bytes 2846
    pvc create time 00:10:53, last time pvc status changed 00:10:53


Configuring Frame Relay DLCI Prioritization

Data-link connection identifier (DLCI) prioritization is the process whereby different traffic types are placed upon separate DLCIs so that a Frame Relay network can provide a different committed information rate for each traffic type. It can be used in conjunction with either custom queuing or priority queuing to provide bandwidth management control over the access link to the Frame Relay network. In addition, some Frame Relay service providers and Frame Relay switches (such as the Stratacom Internetwork Packet Exchange [IPX], IGX and BPX or AXIS switches) actually provide prioritization within the Frame Relay cloud based on this priority setting.


Implementation Considerations

When implementing DLCI prioritization, please note the following points:



  • If a secondary DLCI goes down, you lose traffic destined for that queue only.

  • If you lose the primary DLCI, the subinterface goes down and you lose all traffic.

Network Diagram

In order to use this setup, you need to have four DLCIs for the side that will use the DLCI prioritization. In this example, we have configured Spicey for priority queueing as follows:

  • Ping is in the high-priority queue

  • Telnet is in the medium-priority queue

  • File Transfer Protocol (FTP) is in the normal-priority queue

  • All other IP traffic is in the low-priority queue
Note: Make sure you configure the DLCIs to correspond with the priority list, or the system will not use the correct queue.


Configurations
  • Spicey

  • Prasit



debug and show Commands

Use the following show and debug commands to test that your network is operating properly. Before issuing debug commands, please see Important Information on Debug Commands.


  • show frame-relay pvc

  • show frame-relay map

  • show queueing priority

  • debug priority

The output shown below is a result of entering these commands on the devices we are using in this sample configuration.


Spicey

    Spicey#show frame-relay pvc
    PVC Statistics for interface Serial0 (Frame Relay DTE)
    Active Inactive Deleted Static
v     Local 4 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 140, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0.1
    input pkts 106 output pkts 15 in bytes 6801
    out bytes 1560 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 0 out bcast bytes 0
    pvc create time 00:29:22, last time pvc status changed 00:20:37
    Priority DLCI Group 1, DLCI 140 (HIGH), DLCI 180 (MEDIUM)
    DLCI 190 (NORMAL), DLCI 200 (LOW)
    DLCI = 180, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0.1
    input pkts 0 output pkts 51 in bytes 0
    out bytes 2434 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 0 out bcast bytes 0
    pvc create time 00:29:23, last time pvc status changed 00:14:48
    DLCI = 190, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0.1
    input pkts 0 output pkts 13 in bytes 0
    out bytes 3653 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 13 out bcast bytes 3653
    pvc create time 00:29:23, last time pvc status changed 00:14:28
    DLCI = 200, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0.1
    input pkts 0 output pkts 42 in bytes 0
    out bytes 2554 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 10 out bcast bytes 500
    pvc create time 00:29:24, last time pvc status changed 00:14:09
    Spicey#show frame-relay map
    Serial0.1 (up): point-to-point dlci, dlci 140(0x8C,0x20C0), broadcast
    status defined, active
    Priority DLCI Group 1, DLCI 140 (HIGH), DLCI 180 (MEDIUM)
    DLCI 190 (NORMAL), DLCI 200 (LOW)
    Spicey#show queueing priority
    Current priority queue configuration:
    List Queue Args
    1 high protocol ip list 102
    1 medium protocol ip tcp port telnet
    1 normal protocol ip tcp port ftp
    1 low protocol ip
  To verify the priority queue, use the debug priority command.
    Spicey#debug priority
    Priority output queueing debugging is on
    Spicey#ping 123.123.123.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 123.123.123.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 44/45/48 ms
    Spicey#

    *Mar 1 00:32:30.391: PQ: Serial0: ip (s=4.0.1.1, d=123.123.123.1) ->high
    *Mar 1 00:32:30.395: PQ: Serial0: ip (s=4.0.1.1, d=123.123.123.1) ->high
    *Mar 1 00:32:30.399: PQ: Serial0 output (Pk size/Q 104/0)
    *Mar 1 00:32:30.439: PQ: Serial0: ip (s=4.0.1.1, d=123.123.123.1) ->high
    *Mar 1 00:32:30.443: PQ: Serial0: ip (s=4.0.1.1, d=123.123.123.1) ->high
    *Mar 1 00:32:30.447: PQ: Serial0 output (Pk size/Q 104/0)
    *Mar 1 00:32:30.487: PQ: Serial0: ip (s=4.0.1.1, d=123.123.123.1) ->high
    *Mar 1 00:32:30.491: PQ: Serial0: ip (s=4.0.1.1, d=123.123.123.1) ->high
    *Mar 1 00:32:30.495: PQ: Serial0 output (Pk size/Q 104/0)
    *Mar 1 00:32:30.535: PQ: Serial0: ip (s=4.0.1.1, d=123.123.123.1) ->high
    *Mar 1 00:32:30.539: PQ: Serial0: ip (s=4.0.1.1, d=123.123.123.1) ->high
    *Mar 1 00:32:30.543: PQ: Serial0 output (Pk size/Q 104/0)
    *Mar 1 00:32:30.583: PQ: Serial0: ip (s=4.0.1.1, d=123.123.123.1) ->high
    *Mar 1 00:32:30.587: PQ: Serial0: ip (s=4.0.1.1, d=123.123.123.1) ->high
    *Mar 1 00:32:30.587: PQ: Serial0 output (Pk size/Q 104/0)Spicey#
    Spicey#telnet 123.123.123.1
    Trying 123.123.123.1 ... Open
    User Access Verification

    Password:
    *Mar 1 00:32:59.447: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.451: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.451: PQ: Serial0 output (Pk size/Q 48/1)
    *Mar 1 00:32:59.475: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.479: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.483: PQ: Serial0 output (Pk size/Q 44/1)
    *Mar 1 00:32:59.487: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.487: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.491: PQ: Serial0 output (Pk size/Q 53/1)
    *Mar 1 00:32:59.495: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.499: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.499: PQ: Serial0 output (Pk size/Q 44/1)
    *Mar 1 00:32:59.511: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.511: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.515: PQ: Serial0 output (Pk size/Q 47/1)
    *Mar 1 00:32:59.519: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.519: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.523: PQ: Serial0 output (Pk size/Q 47/1)
    *Mar 1 00:32:59.527: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.527: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.531: PQ: Serial0 output (Pk size/Q 53/1)
    *Mar 1 00:32:59.539: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.543: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.547: PQ: Serial0 output (Pk size/Q 47/1)
    *Mar 1 00:32:59.751: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.755: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:32:59.755: PQ: Serial0 output (Pk size/Q 44/1)
    Password:

  Other IP traffic goes through the low queue.
    Spicey#
    *Mar 1 00:53:57.079: PQ: Serial0 output (Pk size/Q 13/0)
    *Mar 1 00:53:58.851: PQ: Serial0: ip -> low
    *Mar 1 00:53:58.907: PQ: Serial0: ip -> low
    *Mar 1 00:53:58.907: PQ: Serial0 output (Pk size/Q 36/3)
    *Mar 1 00:53:59.459: PQ: Serial0: ip -> low
    *Mar 1 00:53:59.463: PQ: Serial0: ip -> low
    *Mar 1 00:53:59.463: PQ: Serial0 output (Pk size/Q 50/3)
    Spicey#


Prasit

    Prasit#show frame-relay pvc
    PVC Statistics for interface Serial1 (Frame Relay DTE)
    Active Inactive Deleted Static

    Local 1 0 0 0
    Switched 0 0 0 0
    Unused 0 0 0 0

    DLCI = 150, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial1
    input pkts 134 output pkts 119 in bytes 12029
    out bytes 7801 dropped pkts 0 in FECN pkts 0
    in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
    in DE pkts 0 out DE pkts 0
    out bcast pkts 18 out bcast bytes 1260
    pvc create time 00:21:15, last time pvc status changed 00:21:15
    Prasit#show frame-relay map
    Serial1 (up): ip 4.0.1.1 dlci 150(0x96,0x2460), dynamic,
    broadcast, status defined, active
    Prasit#ping 124.124.124.1
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 124.124.124.1, timeout is 2 seconds:

!!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 44/45/48
    Here is the debug output shown on Spicey when you use the command above to ping to Spicey from Spicey#
    *Mar 1 00:33:26.755: PQ: Serial0 output (Pk size/Q 13/0)
    *Mar 1 00:33:28.535: PQ: Serial0: ip (s=124.124.124.1, d=4.0.1.2) ->high
    *Mar 1 00:33:28.539: PQ: Serial0: ip (s=124.124.124.1, d=4.0.1.2) ->high
    *Mar 1 00:33:28.543: PQ: Serial0 output (Pk size/Q 104/0)
    *Mar 1 00:33:28.583: PQ: Serial0: ip (s=124.124.124.1, d=4.0.1.2) ->high
    *Mar 1 00:33:28.587: PQ: Serial0: ip (s=124.124.124.1, d=4.0.1.2) ->high
    *Mar 1 00:33:28.587: PQ: Serial0 output (Pk size/Q 104/0)
    *Mar 1 00:33:28.631: PQ: Serial0: ip (s=124.124.124.1, d=4.0.1.2) ->high
    *Mar 1 00:33:28.635: PQ: Serial0: ip (s=124.124.124.1, d=4.0.1.2) ->high
    *Mar 1 00:33:28.635: PQ: Serial0 output (Pk size/Q 104/0)
    *Mar 1 00:33:28.679: PQ: Serial0: ip (s=124.124.124.1, d=4.0.1.2) ->high
    *Mar 1 00:33:28.683: PQ: Serial0: ip (s=124.124.124.1, d=4.0.1.2) ->high
    *Mar 1 00:33:28.683: PQ: Serial0 output (Pk size/Q 104/0)
    *Mar 1 00:33:28.723: PQ: Serial0: ip (s=124.124.124.1, d=4.0.1.2) ->high
    *Mar 1 00:33:28.727: PQ: Serial0: ip (s=124.124.124.1, d=4.0.1.2) ->high
    *Mar 1 00:33:28.731: PQ: Serial0 output (Pk size/Q 104/0)

    Prasit#telnet 124.124.124.1
    Trying 124.124.124.1 ... Open
    User Access Verification
    Password:
    Spicey>exit
    [Connection to 124.124.124.1 closed by foreign host]
    Prasit#

  Here is the debug output shown on Spicey when you use the command above to telnet to Spicey from Prasit.
    Spicey#
    *Mar 1 00:33:54.499: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:54.499: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:54.503: PQ: Serial0 output (Pk size/Q 48/1)
    *Mar 1 00:33:54.527: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:54.531: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:54.531: PQ: Serial0 output (Pk size/Q 56/1)
    *Mar 1 00:33:54.547: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:54.551: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:54.555: PQ: Serial0 output (Pk size/Q 86/1)
    *Mar 1 00:33:54.559: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:54.563: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:54.563: PQ: Serial0 output (Pk size/Q 47/1)
    *Mar 1 00:33:54.571: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:54.575: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:54.575: PQ: Serial0 output (Pk size/Q 47/1)
    *Mar 1 00:33:54.779: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:54.783: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:54.783: PQ: Serial0 output (Pk size/Q 44/1)
    *Mar 1 00:33:56.755: PQ: Serial0 output (Pk size/Q 13/0)
    *Mar 1 00:33:57.143: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:57.143: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:57.147: PQ: Serial0 output (Pk size/Q 44/1)
    *Mar 1 00:33:57.447: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:57.447: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:57.451: PQ: Serial0 output (Pk size/Q 44/1)
    *Mar 1 00:33:57.899: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:57.899: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:57.903: PQ: Serial0 output (Pk size/Q 53/1)
    *Mar 1 00:33:59.491: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:59.495: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:59.495: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:59.711: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:59.715: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:59.715: PQ: Serial0 output (Pk size/Q 45/1)
    *Mar 1 00:33:59.951: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:59.951: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:33:59.955: PQ: Serial0 output (Pk size/Q 45/1)
    *Mar 1 00:34:00.123: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:34:00.123: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:34:00.127: PQ: Serial0 output (Pk size/Q 45/1)
    *Mar 1 00:34:00.327: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:34:00.327: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:34:00.331: PQ: Serial0 output (Pk size/Q 46/1)
    *Mar 1 00:34:00.495: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:34:00.499: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:34:00.499: PQ: Serial0 output (Pk size/Q 44/1)
    *Mar 1 00:34:00.543: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:34:00.543: PQ: Serial0: ip (tcp 23) -> medium
    *Mar 1 00:34:00.547: PQ: Serial0 output (Pk size/Q 44/1)


Frame Relay Broadcast Queue

Broadcast queue is a major feature that is used in medium to large IP or IPX networks where routing and service access point (SAP) broadcasts must flow across the Frame Relay network. The broadcast queue is managed independently of the normal interface queue, has its own buffers, and has a configurable size and service rate. This broadcast queue is not used for bridging spanning-tree updates (BPDUs) because of timing sensitivities. These packets will flow through the normal queues. The interface command to enable broadcast queue follows:

frame-relay broadcast-queue size byte-rate packet-rate

A broadcast queue is given a maximum transmission rate (throughput) limit measured in bytes per second and packets per second. The queue is serviced to ensure that only this maximum is provided. The broadcast queue has priority when transmitting at a rate below the configured maximum, and hence has a guaranteed minimum bandwidth allocation. The two transmission rate limits are intended to avoid flooding the interface with broadcasts. The actual limit in any second is the first rate limit that is reached. Given the transmission rate restriction, additional buffering is required to store broadcast packets. The broadcast queue is configurable to store large numbers of broadcast packets. The queue size should be set to avoid loss of broadcast routing update packets. The exact size depends on the protocol being used and the number of packets required for each update. To be safe, the queue size should be set so that one complete routing update from each protocol and for each data-link connection identifier (DLCI) can be stored. As a general rule, start with 20 packets per DLCI. The byte rate should be less than both of the following:



  • N/4 times the minimum remote access rate (measured in bytes per second), where N is the number of DLCIs to which the broadcast must be replicated

  • 1/4 the local access rate (measured in bytes per second)

The packet rate is not critical if the byte rate is set conservatively. In general, the packet rate should be set assuming 250-byte packets. The defaults for the serial interfaces are 64 queue size, 256,000 bytes per second (2,048,000 bps), and 36 pps. The defaults for the High Speed Serial Interfaces (HSSI) are 256 queue size, 1,024,000 bytes per second (8,192,000 bps), and 144 pps.



Traffic Shaping

Traffic shaping uses a rate control mechanism called a token bucket filter. This token bucket filter is set as follows:

excess burst plus committed burst (Bc + Be) = maximum speed for the virtual circuit (VC)

Traffic above the maximum speed is buffered in a traffic shaping queue which is equal to the size of the weighted fair queue (WFQ). The Token Bucket filter does not filter traffic, but controls the rate at which traffic is sent on the outbound interface. For more information on token bucket filters, please see the Po