Stack to Stack connection

[ifoam]

We currently have a 4 switch stack of 3750's.

We want to order two more 3750's. I think it would be a better idea to make two stacks of 3 each.

What kind of connection options are available to interconnect the stacks? I know there is 16gbps between the switches but what about between the stacks?

I'd like for them to be separate.

 

[brianinms]

You can use etherchannel and join up to 8 ports per group. For bandwidth sake you would be better by stacking them.

 

[vipergg]

I see no advantage to separating them and then trying to connect them togther with something like a etherchannel , it kind of defeats the whole reason for the stacking technology . you can stack up to like 9 together i believe.

 

[ifoam]

thanks for that etherchannel suggestion.

the reason is redundancy.

 

[brianinms]

They are just as redundant if you stack them.

 

[vipergg]

Brian is correct , they are fully redundant when stacked . Every switch in the stack has the complete configuration of the entire stack . The configuration is handled by the stackmaster , if for some reason the stackmaster dies a new stackmaster is elected and the stack continues to run as normal . Where you have to think about things is if you have multiple uplinks out of the stack do not put them all on one switch , put them on different switches within the stack and this will give you full redundancy .

 

[ifoam]

well, if the stackmaster dies, so do all the clients connected to it, correct?

In our case, the reason for two stacks, is to have each server (34), connected to each stack...buuutttt i guess that doesn't make sense because a failure is confined to the switch.

hmmm, thanks braininms and vipergg, you are correct.

 

[johnilu]

If the stack master dies a new master is elected. Your uplink should be to the first and second switch in the stack so that if one uplink dies (connected to the master) the secondary link will take up the load. In the mean time under normal operations they can be set up as an etherchannel