Catalyst 2950 stackability

[pc2]

Hi,

I'm trying to find information about the stackability of Catalyst 2950. Do I need aditional SW or HW or is it possible to connect the ports together just like that? What's the limit for the number of Catalysts I can connect together?

Thanks in advance.

Patricia

[millerv]

Do you plan on using Cisco cluster manager ? If So, keep it to 9 or less.

My biggest concern would be making sure I knew who the root bridge was in spanning tree.

[pc2]

Thank you! I don't think we'll be having more than 6, so from what you say I think it will be OK.

Regards.

[sluke]

Why 9? I've just run a stack of 16 past Cisco and they said it should be ok, I intend running it as two stacks of eight in terms of clustering so I'd have a cluster manager for each stack, however, in stacking terms, I'd have 16.

[millerv]

origianl spec for cm limited it to nine, if you can do more great!

[sluke]

A misunderstanding here I think. I have proposed 16 switches in the same STP domain but two separate clusters each having eight. I believe the clustering spec originally limited cluster stacks to 3 and then later on expanded it to eight (no more than seven bridge hops between CM Master and furtherest switch) but I think this is not the same as the STP bridge hop limit. Any ideas what the STP bridge hop limit is? I think the STP to cluster relationship is not one-to-one, i.e. you can have several clusters in the same STP domain. Any views?

[sluke]

Further clarification:

I've spoken to Cisco about this. It looks like they advocate a seven hop limit where possible, so root bridge placement is critical, but also say that STP timers can be tuned to allow more switches per stack. My original design of 16 switches has been canned, we are going for max of 8 per stack. This assumes root bridge placement on aggregator switches for multiple stacks.

HTH