Maximum number of subinterface on a 4232-L3 blade

[sjbauer]

What is the maximum number of subinterfaces that can be configured on the ws-x4232-L3 blade in a cat4000 chasis?

[bsivasub]

I don't think there is any documented limit. How many sub-interfaces are you planning to create ?

[sjbauer]

We were looking to create around 520 interfaces to support our goal of having a vlan per dorm room connection.

[tstevens]

There is a documented limit, it is 250 per interface:

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat4000/inst_nts/78_10164.htm#xtocid77

My understanding is that this limit also applies to a port channel interface, ie, if you channel gig 3-4, you can have up to 250 subi/fs on the port-channel i/f.

[sjbauer]

I knew about that limit... The question is if there is enough memory on the card to handle the full 1000 interfaces since there are 4 gigabit interfaces on the card..

[mleichtfried]

Take care: only 2 of the GE´s are connected to the backplane. The others are directly conected to the Frontpanel. They are routed only and there is no L2 connection to the backplane for them.

The other thing I am thinking of are the Spanning Tree sessions. Are you run SPT and PVST+ or dissabled SPT?. 500 SPT´s might be a problem for the Cat´s.

[sjbauer]

We will not be running SPT since we are looking at setting each port to an individual vlan which would then be routed between the vlan's by the 4232-L3. The fact that two of the routers 4 interfaces are on the front panel is fine for us since we use them to connection to the other two dorms that we are doing the vlan per port setup.