Fibre Link issues 3750 - 2960

[TweakMYbox]

OK, I am at my wits end!

Our core switch is a 3750. We just purchased a 2960 with a GLC-SX-MM GBIC transceiver. Our 3750 has 1000BASE-SX GBICS. We are using 50/125 MultiMode fibre.

I have set 'SPEED NONEGOTIATE' on both ends.

When I connect the 2960 to the 3750, a link light comes up on the 3750, but not on the 2960. The 2960 shows DOWN/DOWN.

It appears that the 3750 is receiving, but NOT transmitting. When I pull the fibre from the 2960, I do not see the red-ommiting light, but I do when I pull the fibre from the 3750.

I've compared the Interface config with others, and it looks good. Anyone else ever seen this? HELP!?!

Mike Fegan

http://www.TweakMyBox.com

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[baddos]

I beleive you have to use 62.5/125 multimode fiber for 1000baseSX.

 

[wabob]

The Cisco 2960 has a dual-purpose uplink port (one SFP and one RJ45). You may need to go in to interface config mode and hard-code it as an SFP module:

(config-if)# media-type sfp

I ran into this before when the fiber uplink port on a 2960 did not work properly...



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