Tip

This is the documentation for the 25.06 version. Looking for the documentation of the latest version? Have a look here.

IS-IS over Ethernet Interface¶

In this example R1 and R2 are connected via private link connected to an Ethernet interface. This could be RJ-45 copper, fiber, DAC, or other types so long as it appears as an Ethernet interface to the dataplane.

This example configures R1 first, followed by R2.

Note

This example assumes other configuration not mentioned is already present in TNSR as described in Required Information.

Configure R1¶

The first item to configure is the interface connected between R1 to R2. Enable the interface and add an IP address:

r1 tnsr(config)# interface CCLINK
r1 tnsr(config-interface)# ip address 10.127.0.1/30
r1 tnsr(config-interface)# enable
r1 tnsr(config-interface)# exit

Now define and configure the IS-IS server using the NET for R1 which is formed by combining the AFI, Area ID, System ID, and NSEL:

r1 tnsr(config)# route dynamic isis
r1 tnsr(config-frr-isis)# server vrf default
r1 tnsr(config-isis)# area-tag exco
r1 tnsr(config-isis)# net 49.0001.0100.0200.0001.00
r1 tnsr(config-isis)# is-type level-1
r1 tnsr(config-isis)# exit

Configure the interface connected to R2 for IS-IS with the same ID as the server and enable IPv4:

r1 tnsr(config-frr-isis)# interface CCLINK
r1 tnsr(config-isis-if)# area-tag exco
r1 tnsr(config-isis-if)# ipv4
r1 tnsr(config-isis-if)# exit

Configure the LAN interface for IS-IS with the same ID as the server and for IPv4, but mark the LAN as passive as there are no routers connected to the LAN:

r1 tnsr(config-frr-isis)# interface LAN
r1 tnsr(config-isis-if)# area-tag exco
r1 tnsr(config-isis-if)# passive
r1 tnsr(config-isis-if)# ipv4
r1 tnsr(config-isis-if)# exit

Lastly, enable IS-IS and exit:

r1 tnsr(config-frr-isis)# enable
r1 tnsr(config-frr-isis)# exit

Configure R2¶

The first item to configure is the interface connected between R2 to R1. Enable the interface and add an IP address:

r2 tnsr(config)# interface CCLINK
r2 tnsr(config-interface)# ip address 10.127.0.2/30
r2 tnsr(config-interface)# enable
r2 tnsr(config-interface)# exit

Now define and configure the IS-IS server using the NET for R1 which is formed by combining the AFI, Area ID, System ID, and NSEL:

r2 tnsr(config)# route dynamic isis
r2 tnsr(config-frr-isis)# server vrf default
r2 tnsr(config-isis)# area-tag exco
r2 tnsr(config-isis)# net 49.0001.0100.3000.0001.00
r2 tnsr(config-isis)# is-type level-1
r2 tnsr(config-isis)# exit

Configure the interface connected to R1 for IS-IS with the same ID as the server and enable IPv4:

r2 tnsr(config-frr-isis)# interface CCLINK
r2 tnsr(config-isis-if)# area-tag exco
r2 tnsr(config-isis-if)# ipv4
r2 tnsr(config-isis-if)# exit

Configure the LAN interface for IS-IS with the same ID as the server and for IPv4, but mark the LAN as passive as there are no routers connected to the LAN:

r2 tnsr(config-frr-isis)# interface LAN
r2 tnsr(config-isis-if)# area-tag exco
r2 tnsr(config-isis-if)# passive
r2 tnsr(config-isis-if)# ipv4
r2 tnsr(config-isis-if)# exit

Lastly, enable IS-IS and exit:

r2 tnsr(config-frr-isis)# enable
r2 tnsr(config-frr-isis)# exit

Next Steps¶

The configuration is now complete. Proceed to Finish Up for information on testing.