1 router to 2 switches

[gele-piukr]

I'm wondering whether anyone uses a configuration where one router with two interfaces is connected to two different switches, the first interface is the primary with an IP address and the standby interface can take over if the primary goes down (and use the same common IP).

Basically, I'm looking for a feature similar to Teaming NIC's in servers.

Is there a feature in Cisco routers which can support this configuration?

Thanks for your help!

Robert

[Richard Burts]

It sounds like you are asking for HSRP on two interfaces on the same router. This will not work. Cisco will not allow two LAN interfaces on the same router to be configured in the same network.

An alternative that you might consider is to configure the first interface with backup interface pointing to the second interface. With backup interface only one interface is active at a time and I think this would get around the restriction.

I have not configured this on a router and am not certain that it would work. But conceptually it should do what you want.

HTH

Rick

[gele-piukr]

Rick, you are right, I'm looking for an HSRP like feature implemented in one device. I know that I can't use HSRP on the same router due to the "limitations" of IP address assignment.

It's a good idea to use backup interface, however I still don't see how can I use on common IP address for the two interfaces. Maybe I should use unnumbered Ethernet interfaces linked to a single Loopback.

Thanks

Robert

[cpubob]

Your looking for IRB.

you setup the two interface in a bridge group with NO ip addresses. You then configur your BVI "brige virtual interface" that corresponds to the bridge group number with an ip address. Thats the default gateway the clients use, and now you have two paths to the router.

Example.

conf t

bridge irb

bridge 1 protocol ieee

bridge 1 route ip

int e 0

no ip add

bridge-group 1

no shut

int e 1

no ip add

bridge-group 1

no shut

int bvi 1

ip add 1.1.1.1 255.255.255.0

no shut