CRC Errors on From Cat4006!!!

[cmalleh]

Hi,

I'm having persistent CRC errors when I connect anything to one of my CAT 4006 switch ports(WS-X4412-2GB-T line card).

All connected switches report rxCRCAlignerrors and users lose connectivity to Servers and the Internet. FCS Rcv errors pile up!!

I've replaced:

i) Line Card (WS-X4412-2GB-T 12 Cat 1Gb/s and 2 Fiber 1Gb/s).

ii) Supervisor II Engine

iii)Patch cables

iv) Changed from 2980 to a 3548 switch

v) Upgraded IOS from 6.3(5) to 7.4(2) on the CAT4K.

vi) Changed Fiber Pairs.

Nothing works so far.

Any Ideas???

[Georg Pauwen]

Hello,

I would check if any remote devices are sending the bad frames. According to Cisco, CRC errors can also come from a remote device attached via an ISL trunk. Most Catalyst line cards do not check the CRC of a packet they receive from the backplane and forward on a trunk. Can you connect a sniffer to your switch ?

Regards,

GP

[rfroom]

Is it happeningly only on 1 switch port of the 12? If so, which port? Or does it happen on all ports. If it happens on any port, then you probably need to look at what is connecting to the switch.

Generally, fcs rcv errors are a result of duplex mismatch.