Catalyst 3550 with GBIC

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Aug 21st, 2008
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I'm trying to connect two identical Catalyst 3550 via GBIC. When I connect the two switches port g0/1 on both switches becomes up, but they can't talk to each other. They both have the same IOS, Version 12.1(12c)EA1.

Usually when I GSTACK two 3750, the second switch becomes part of stack automatically and I can do a show inter and see inter g1/0/48 to g2/0/48, but this is not the case with these 3550.

Is there any commands that I need to do on these 3550 to join them together in one stack?


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sachinraja Thu, 08/21/2008 - 21:36
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with 3550 you do a cascading and not stacking. stackwise technology is supported only in 3750's. when you cascade 3550 switches, you need to apply trunking configurations (dot1q or ISL) and make them talk over different VLANs. How are you testing reachability between the switches ? You can configure a common management VLAN (say VLAN 10) , configure trunk, and you should be able to ping between the switches.


satish_zanjurne Thu, 08/21/2008 - 21:40
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Using 3750 you do stack , where you use special stack cable, that's why it shows as Gi1/0/48 & 2/0/48.

For 3550 are you trying to create cluster, then find below link.

If you are not trying to create cluster, and you are using GBIC, it means you are trying to connect both 3550 through fiber.

Can you attach the config of both 3550 , and also "show interface gi0/1" of both switches ??


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