How to configure Cisco Gigastack GBIC Interfaces

Unanswered Question
Dec 16th, 2008


I want to connect two 3550-12T (with current ios version) by using two gigastack gbics. Is there any software configuration necessary or do I just have to interconnect the 2 switches?

Furthermore are there any ios commands which show the current state of the stack like you know from 3750 stacks?

Best Regards,

Thorsten Steffen

I have this problem too.
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ohassairi Tue, 12/16/2008 - 01:21

just connect them, but you will not obtain a stack like 3750. you will only have a 1g cascade. consider it as a normal cascade

thorsten.steffen Tue, 12/16/2008 - 06:37

In this scenario, would there be any difference between using the gigastack gbics and normal 1000BaseT gbics? In other words, are there any benefits when using the gigastack gbics?

milan.kulik Tue, 12/16/2008 - 06:44


there is one benefit: price.

If I remember correctly, gigastack GBIC is half price of 1000BaseT GBIC.

If stacking more switches, you can even use half-duplex gigastack connection and reduce the number of GBICs necessary.



glen.grant Tue, 12/16/2008 - 08:34

Gigastack gbics are also 1000/half duplex and with the associated collision domain .

milan.kulik Tue, 12/16/2008 - 08:43

They are full-duplex if only one cable connected (i.e., only one of two ports occupied on stacking GBIC).

Which means, with two switches connected via stacking GBICs, you get full-duplex.




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