3750 and stackwise

emadehsan · ‎04-12-2008

Dear all

I have two 3750g and four 2960.

i want to connect each 2960 in both 3750

for redundancy. can you give and idea about the solution?

should i connect 3750(s) with stack or with normal cable ?

Edison Ortiz · ‎04-12-2008

You should connect the 3750s with the stackwise cable (maximum throughput this way) and uplink the 2960s to these devices by using the Giga uplink ports.

HTH

__

Edison.

emadehsan · ‎04-12-2008

by the way how can STP root and other issued configure on 3750 stacked?

Edison Ortiz · ‎04-12-2008

The stacked switches will run as a single switch. The STP process will occur between the stacked 3750 and the 2960, not within the 3750.

With that said, I recommend forcing the 3750s to be the root of all Vlans as you will have greater redundancy with that design in case of hardware failure.

HTH,

__

Edison.

Joseph W. Doherty · ‎04-13-2008

If supported on the 2960, make a dual Etherchannel and connect one link to each 3750G that's been stacked with the other. This allows usage of both unlink ports without one needing to be blocked in a spanning tree configuration. (It also precludes the need for STP since there are no logical loops, but good idea to have it enabled; preferably using one of the newer rapid variants.)

PS:

Using the stack cable between 3750s effectively provides an eight gig link between them. Becoming one device offers different advantages. For instance, you can route between VLANs just by activation of "ip routing", a routing protocol or explicit statics isn't needed as might be if the two 3750G were kept as individual L3 devices.

If routing on the 3750Gs, use HSRP so the gateway MAC doesn't change with failure of the stack master.