same SVI in whole network

[sherrikhan]

Hi

 We have couple of switches in datacentre (old one) and i can see that same subnet SVI is used in many switches. What is the purpose of that???. Like vlan 10 has SVI 10.1.1.0/24 on core switch. The core switch is connected to an access switch which has vlan 10 SVI of  10.1.1.2/24 . The port is trunk between the two switches. I am trying to get my head around why people use that?

[Seb Rupik]

Hi there,

That would be legitimate configuration if VLAN10 was your management network, in the absence of an out of band management network.

cheers,

Seb.

[Joseph W. Doherty]

Two (same VLAN) SVIs, each on different L3 switches, was often used for redundancy. If there's HSRP too, that's likely why.

Another reason to have more than one SVI, would be for load sharing.

More than two SVIs would be rather unusual.

Anytime you have more than one SVI, on different switches, you open yourself up to unicast flooding.