Mapping local and remote DLCIs in Frame Relay involves associating the DLCI values with the appropriate IP addresses of the local and remote endpoints. This mapping allows the routers to forward data packets to the correct destination over the Frame Relay network. Here's how you can map local and remote DLCIs on Cisco routers using Cisco IOS commands:
1. Mapping Local DLCIs to Remote IP Addresses:
To map local DLCIs to remote IP addresses, use the `frame-relay map` command:
```bash Router(config)# interface serial interface_number Router(config-if)# frame-relay map ip remote_ip_address dlci ```
- Replace `interface_number` with the number of the serial interface.
- Replace `remote_ip_address` with the IP address of the remote endpoint.
- Replace `dlci` with the DLCI value associated with the remote endpoint.
For example:
```bash Router(config)# interface serial 0/0 Router(config-if)# frame-relay map ip 192.168.1.2 102 ```
This command maps DLCI 102 to the remote IP address 192.168.1.2.
2. Mapping Remote DLCIs to Local IP Addresses:
Similarly, you can map remote DLCIs to local IP addresses using the `frame-relay map` command:
```bash Router(config)# interface serial interface_number Router(config-if)# frame-relay map ip local_ip_address dlci ```
- Replace `interface_number` with the number of the serial interface.
- Replace `local_ip_address` with the IP address of the local endpoint.
- Replace `dlci` with the DLCI value associated with the local endpoint.
For example:
```bash Router(config)# interface serial 0/0 Router(config-if)# frame-relay map ip 192.168.1.1 101 ```
This command maps DLCI 101 to the local IP address 192.168.1.1.
3. Verification:
Verify the mapping using the `show frame-relay map` command:
```bash Router# show frame-relay map ```
This command displays the mapping between DLCIs and IP addresses configured on the router.
4. Optional Parameters:
- You can include additional parameters in the `frame-relay map` command, such as specifying the broadcast keyword to support broadcast traffic over the Frame Relay network or configuring quality of service (QoS) parameters.
- You can also use inverse ARP (Address Resolution Protocol) to dynamically map DLCIs to IP addresses, eliminating the need for manual configuration. Inverse ARP is enabled by default on Cisco routers.
By mapping local and remote DLCIs to their respective IP addresses, you establish the necessary connectivity between the endpoints over the Frame Relay network, allowing for the transmission of data packets between the devices. Ensure consistency in DLCI mapping on both ends of the Frame Relay connection to ensure proper communication.