frame-relay map

To define the mapping between a destination protocol address and the data-link connection identifier (DLCI) used to connect to the destination address, use the frame-relay map interface configuration command. To delete the map entry, use the no form of this command.

Syntax Description

protocol	Supported protocol, bridging, or logical link control keywords: appletalk, decnet, dlsw, ip, ipx, llc2, rsrb, vines and xns.
protocol-address	Destination protocol address.
dlci	DLCI number used to connect to the specified protocol address on the interface.
broadcast	(Optional) Forwards broadcasts to this address when multicast is not enabled (see the frame-relay multicast-dlci command for more information about multicasts). This keyword also simplifies the configuration of Open Shortest Path First (OSPF) (see the "Usage Guidelines" section for more detail).
ietf	(Optional) Internet Engineering Task Force (IETF) form of Frame Relay encapsulation. Used when the router or access server is connected to the equipment of another vendor across a Frame Relay network.
cisco	(Optional) Cisco encapsulation method.
payload-compress packet-by-packet	(Optional) Packet-by-packet payload compression using the Stacker method.
payload-compress frf9 stac	(Optional) Enables FRF.9 compression using the Stacker method: If the router contains a compression service adapter (CSA), compression is performed in the CSA hardware (hardware compression). If the CSA is not available, compression is performed in the software installed on the VIP2 (distributed compression). If the VIP2 is not available, compression is performed in the router's main processor (software compression).
hardware-options	distributed (Optional) Specifies that compression is implemented in the software that is installed in a VIP2. If the VIP2 is not available, compression is performed in the router's main processor (software compression). This option applies only to the Cisco 7500 series. software (Optional) Specifies that compression is implemented in the Cisco IOS software installed in the router's main processor. csa csa_number (Optional) Specifies the CSA to use for a particular interface. This option applies only to Cisco 7200 series routers.

Defaults

No mapping is defined.

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.
11.3	The payload-compress frf9 stac keyword was added.

Usage Guidelines

There can be many DLCIs known by a router or access server that can send data to many different places, but they are all multiplexed over one physical link. The Frame Relay map defines the logical connection between a specific protocol and address pair and the correct DLCI.

The optional ietf and cisco keywords allow flexibility in the configuration. If no keywords are specified, the map inherits the attributes set with the encapsulation frame-relay command. You can also use the encapsulation options to specify that, for example, all interfaces use IETF encapsulation except one, which needs the original Cisco encapsulation method and can be configured through use of the cisco keyword with the frame-relay map command.

Packet-by-packet compression is Cisco-proprietary and will not interoperate with routers of other manufacturers.

You can disable payload compression by entering the no frame-relay map payload command and then entering the frame-relay map command again with one of the other encapsulation keywords (cisco or ietf).

Use the frame-relay map command to enable or disable payload compression on multipoint interfaces. Use the frame-relay payload-compress command to enable or disable payload compression on point-to-point interfaces.

We recommend that you shut down the interface prior to changing encapsulation types. Although this is not required, shutting down the interface ensures the interface is reset for the new encapsulation.

The broadcast keyword provides two functions: it forwards broadcasts when multicasting is not enabled, and it simplifies the configuration of OSPF for nonbroadcast networks that will use Frame Relay.

The broadcast keyword might also be required for some routing protocols---for example, AppleTalk---that depend on regular routing table updates, especially when the router at the remote end is waiting for a routing update packet to arrive before adding the route.

By requiring selection of a designated router, OSPF treats a nonbroadcast, multiaccess network such as Frame Relay in much the same way as it treats a broadcast network. In previous releases, this required manual assignment in the OSPF configuration using the neighbor interface router command. When the frame-relay map command is included in the configuration with the broadcast keyword, and the ip ospf network command (with the broadcast keyword) is configured, there is no need to configure any neighbors manually. OSPF will now automatically run over the Frame Relay network as a broadcast network. (See the ip ospf network interface command for more detail.)

Examples

The following example maps the destination IP address 172.16.123.1 to DLCI 100:

interface serial 0
 frame-relay map IP 172.16.123.1 100 broadcast
 

OSPF will use DLCI 100 to broadcast updates.

The following example shows FRF.9 compression configuration using the frame-relay map command.

!
interface Serial2/0/1
 ip address 172.16.1.4 255.255.255.0
 no ip route-cache
 encapsulation frame-relay IETF
 no keepalive
 shutdown
 frame-relay map ip 172.16.1.1 105 IETF payload-compression FRF9 stac
!

Related Commands

Command	Description
frame-relay payload-compress	Enables Stacker payload compression on a specified point-to-point interface or subinterface.