CISCO WS-C3560G-48TS Ports 1-48 not negotiating 1000M with neighbor switch

manjesh.michael · ‎07-07-2009

We have two switches CISCO WS-C3560G-48TS in our network. When we connect these two switches via cross cable through any of the ports (1-48) and trying to hard code the speed on both sides as 1000M, interface is going down physically. We have enabled dot1Q trunking. Link is working fine with 100M/Full duplex settings. But not working with 1000M speed. Is this an expected behaviour of ports 1-48 (non SFP ports)? SFP Ports are working fine with 1000M/Full. Please suggest.

Giuseppe Larosa · ‎07-07-2009

Hello Michael,

first of all the switches may support MDXI that is the capability to adapt to the cable type.

If a crossover cable is needed or used it has to be of a special type:

1000 Mbps over UTP uses 4 pairs not 2 pairs so a cable that crosses 1,3 and 2,6 is not enough to get a GE link

see

http://www.cisco.com/en/US/docs/app_ntwk_services/data_center_app_services/css11500series/v7.50_v7.40/installation/guide/Pinouts.pdf

pag 8

Hope to help

Giuseppe

manjesh.michael · ‎07-07-2009

Hi Giuseppe,

Thanks for the lightning response.You mean to say that four twisted-pair Cat5e cable is required to establish back-to-back switch connectivity that supports 1000M speed. We cannot achieve this connectivity using normal cat5 cable.

Thanks and Regards,

Manjesh Michael