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GigaStacking Help Please

Level 2
Level 2

Hi All,

I have a pair of 3750 switches here. I tried to gigastack them.

I increased the priority on switch 1 to make it the master.

I then wrote the configs to memory and shut both switches down while i installed the cables on the back.

When the switches came up, I could get to everything connected to switch 1, but not switch 2.

I then shut both switches down and attempted to revert back. I even factory defaulted switch 2.

No matter what i do.... switch 2 still has...

switch 2 provision ws-c3750g-24ps in the configuration.

I also noticed that all my interfaces changed from G1/0/x to G2/0/x.

I changed the original config file from the original G1/0/x to G2/0/x and now I have restored connectivity to everything on switch 2.

The stackwise cables are not connected at this point.

I am thinking of trying this again, but am a little wary.

Does anyone have any links or information on using Gigastacking.

3 Replies 3

Level 1
Level 1

A few things to keep in mind when gigastacking:

- Gigastacks are not hot swapable

- Always try to upgrade to the newest IOS when using gigastack

- Connecting both stacking cables will have switches revert to half duplex.

So my advise would be : connect only 1 cable from switch to switch, upgrade both ios, reboot. Check if you see a green light on both gigastacks (if you connect both cables, you should get 3 green lights 1 red for spanning tree block)

btw. not sure what you mean with "changed to master".

? Connect only one Gigastack cable ? can you do that?

Yes, in fact it's the only way of getting full duplex. Two cables would increase your redundancy somewhat in a larger stack, but with 2 or 3 switches it's not worth it.