Hello,
I've found myself in some trouble with configuring VRRP and a backup interface on a 1921 router. My LAN edge has two 1921 routers with VRRP configured between them. VRRP is configured to GigabitEthernet0/0.120 subinterface on both routers and connected to two 2960-S switches in a ring topology. Master selection works just fine.
Now, a third 2960-S switch is also located on the same rack as the primary 1921 router, and also connected to the LAN ring. What I was thinking is, that can I connect the primary 1921 router also to the second switch in the rack and just assign that link as a backup interface? Well of course I can, but the problem arose with VRRP. I tried to configure the backup interface (GigabitEthernet0/1 and subinterfaces) on the router with the same commands as the primary interface, but I received a notification on the CLI stating:
% 10.53.10.254 is assigned to another application on GigabitEthernet0/0.120
Is there any way around this?
Is it not possible to equip the backup interface with identical configurations as the primary, when VRRP is implemented?
A topology illustration and the primary router's interface configurations are listed below.
!
interface GigabitEthernet0/0 #primary LAN connection to SW-01 on RACK1
no ip address
duplex full
speed 1000
no mop enabled
backup interface GigabitEthernet0/1 #GigabitEthernet0/1 and subinterfaces will remain in
"Standby mode" status, so long as GigabitEthernet0/0 is active.
!
interface GigabitEthernet0/0.101
encapsulation dot1Q 1 native
ip address 10.53.254.252 255.255.255.0
ip access-group 120 out
no ip proxy-arp
!
interface GigabitEthernet0/0.120
encapsulation dot1Q 20
ip address 10.53.10.252 255.255.128.0
no ip proxy-arp
vrrp 12 ip 10.53.10.254
vrrp 12 priority 102
vrrp 12 track 20 decrement 30
!
interface GigabitEthernet0/1 #backup LAN connection to SW-02 on RACK1, identical configs.
no ip address
duplex full
speed 1000
no mop enabled
!
interface GigabitEthernet0/1.101
encapsulation dot1Q 1 native
ip address 10.53.254.252 255.255.255.0
ip access-group 120 out
no ip proxy-arp
!
interface GigabitEthernet0/1.120
encapsulation dot1Q 20
ip address 10.53.10.252 255.255.128.0
no ip proxy-arp #For identical interface configs, what is missing here is "vrrp 12 ip 10.53.10.254".
vrrp 12 priority 102
vrrp 12 track 20 decrement 30
!
Anybody able to shed some light on this? Would be greatly appreciated!
-Vesa
