Virt Int & Vip

[gagansethi]

Hi All

Have few queries to be verified:

1. With VIP & Virtual Interface configuration & couple of server VLAN's below the CSS on server side, I should be able to use both the gigabit interfaces on the 11503 to connect up and down streams as TRUNK. I mean to ask Virtual intf. & VIP has no problems working on the same TRUNK interface?

2. I understand that Fate sharing and critical service helps full failover (client & server side).

As an upstream router or L3 switch fails or the upstream connecting gigabit interface on CSS fails, the failover happens.

Will the same be applicable WITH downstream L2 switch & CSS interface failure? If any of these on the downstream fails, Will the CSS failover to the standby unit ?

Thanks a lot,

Gagan

[Diego Vargas · Accepted solution]

Hi Gagan,

1. It should not be a problem to have VIP and Virtual Interface redundancy running on the same trunk. The CSS cares about the VLANS and the Virtual Routers.

2. When you have Fate Sharing the CSS will do failover of both the front-end and backend VR (Virtual Routers) when a failure occurs. This is based on a critical service that is pointing to the IP of you upstream and downstream device, so if the healtcheck to one of those devices fail the failover will happen.

If you have a L2 switch in the downstream, there is no way for the CSS to check the health of that device (no IP for the critical service to check), so it wont work this way.

However you can configure a critical phy (critical reporter) to check the status of the interface connected to the L2 device, and do failover if the interface goes down.

Since the VR in the backend side fails, the CSS will succesfully use Fate Sharing and failover on the upstream at the same time.

[gagansethi]

My intention behind posting the query was the worry for layer 2 switch failing situation.

I must say this is THE answer i was looking for. Many thanks

Cheers,

Gagan