Routed Access Layer - Page 2

lamav · ‎08-13-2008

How important is it to have a routed connection between 2 switches in a routed server farm access layer?

So, what we have are 2 server farm switches in an HA configuration with L3 uplinks from each to a routed distribution layer, as well as L2 trunks between access switches.

Question:

How important is it to have a routed connection between the 2 routed access layer switches?

My answer is that it is important. The logic is that the 2 switches are in an HA setup, and that makes it all the more imperative that the IP routing and forwarding information in each switch be the same -- identical/synchronized/converged. This will speed up network convergence in the event of a failure of one of the access switches.

There are others who say that for an ACCESS layer, it is not so important because -- and this is where I get fuzzy regarding the stance -- that L2 switching is faster than routing and therefore....I dont know the rest of the argument. maybe you can fill me in. :-)

Thanks

Victor

lamav · ‎08-14-2008

Gotcha.

I thought maybe there was an industry best practice, a rationale that permeates the industry, that says that it is a good idea to have that routed connection.

Thanks

Victor

By the way, I didnt rate your post with a 3. I gave it a 5.

andrew.burns · ‎08-15-2008

Hi,

Regarding best practise, Cisco have a Design Guide on this very topic that makes excellent reading.

http://www.cisco.com/application/pdf/en/us/guest/netsol/ns107/c649/ccmigration_09186a008073377d.pdf

Chapter 6 covers the access-layer, where all options validated by Cisco are described in detail - and I couldn't see that routed connection mentioned anywhere...

HTH

Andrew.