Showing results for 
Search instead for 
Did you mean: 

GigaStacking Help Please


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


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.

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Recognize Your Peers