Layer 2 Data Center Access Layer Redundancy for VMWare Servers

Jul 23, 2009 2 Replies

I am stumped on designing a layer 2 redundant design for our data center. Right now we are the 3 tier Cisco model, core, dist, access and the vmware servers are located on 2 trunked access layer switches each with routed uplinks to the distribution switches. We need to add



2 more switches to the same vlans for vmware vmotion to work properly, i.e. trunk those vlans over to 2 other switches. Do I turn the distribution switches into layer 2 or add more switches? I am unable to come up with a bullet proof design. Everything except using vss or a nexus 7000 vpc has at least one point of failure. The servers are all dual nic teamed.

Just curious if anyone else is having this delima and how they figured out how to make it into a reliable design.


Doesn't the current version of VM support vmotion over layer

3....thought I read that somewhere. Other than that, your options are limited. Keep the existing model and extend fiber between the two access pairs for that one private vlan is probably the least intrusive, as starting to run spanning-tree defeats your distributed layer 3 model. Long term, vss/vpc will be the answer. Or move some of the non vmotion connections to the second pair, freeing up individual ports for vmotion that you can run back to the original pair. Of course this gets tough if you have structured cabling.

vmotion is a layer 2 protocol only. This is primarily why cisco is preaching vpc's.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required