Example:
!Router A
RP/0/0/CPU0:RouterA(config)# router isis ring
RP/0/0/CPU0:RouterA(config-isis)# net 00.0000.0000.0001.00
RP/0/0/CPU0:RouterA(config-isis)# address-family ipv4 unicast
RP/0/0/CPU0:RouterA(config-isis)# metric-style wide
RP/0/0/CPU0:RouterA(config-isis-af)# exit
!Router B
RP/0/0/CPU0:RouterB(config)# router isis ring
RP/0/0/CPU0:RouterB(config-isis)# net 00.0000.0000.0002.00
RP/0/0/CPU0:RouterB(config-isis)# address-family ipv4 unicast
RP/0/0/CPU0:RouterB(config-isis-af)# exit
!Router C
RP/0/0/CPU0:RouterC(config)# router isis ring
RP/0/0/CPU0:RouterC(config-isis)# net 00.0000.0000.0003.00
RP/0/0/CPU0:RouterC(config-isis)# address-family ipv4 unicast
RP/0/0/CPU0:RouterA(config-isis)# metric-style wide
RP/0/0/CPU0:RouterC(config-isis-af)# exit
Step 3
Configure IPv4 and IPv6 address families on the loopback interfaces of Routers A, B, and C.
Example:
RP/0/0/CPU0:Router(config-isis)# interface loopback0
RP/0/0/CPU0:Router(config-isis-if)# address-family ipv4 unicast
RP/0/0/CPU0:Router(config-isis-if-af)# exit
RP/0/0/CPU0:Router(config-isis-if)# address-family ipv6 unicast
RP/0/0/CPU0:Router(config-isis-if-af)# exit
RP/0/0/CPU0:Router(config-isis-if)# exit
RP/0/0/CPU0:Router(config-isis)#
Step 4
Configure the link metrics on the router interfaces.
Example:
! Configuration for Router A Interface GigabitEthernet 0/0/0/0 with Router B is shown here. Similarly,
configure other router interfaces.
RP/0/0/CPU0:RouterA(config-isis)# interface GigabitEthernet 0/0/0/0
RP/0/0/CPU0:RouterA(config-isis-if)# address-family ipv4 unicast
RP/0/0/CPU0:RouterA(config-isis-if-af)# metric 10
RP/0/0/CPU0:RouterA(config-isis-if-af)# exit
RP/0/0/CPU0:RouterA(config-isis-if)# address-family ipv6 unicast
RP/0/0/CPU0:RouterA(config-isis-if-af)# exit
RP/0/0/CPU0:RouterA(config-isis-if)# exit
RP/0/0/CPU0:RouterA(config-isis)#
Step 5
Confirm your configuration by viewing the route prefixes on Routers A, B, and C.
Example:
! The outputs for Router A are shown here. Similarly, view the outputs for Routers B and C.
RP/0/0/CPU0:RouterA# show route
Tue Oct 13 13:55:18.342 PST
Codes: C - connected, S - static, R - RIP, B - BGP, (>) - Diversion path
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 - ISIS, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, su - IS-IS summary null, * - candidate default
U - per-user static route, o - ODR, L - local, G - DAGR, l - LISP
A - access/subscriber, a - Application route
M - mobile route, (!) - FRR Backup path
Gateway of last resort is not set
Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide, Release 5.3.x
398
Implementing IS-IS
Example: Configuring IS-IS To Handle Router Overload