Cisco Switch question

[rn4it]

I have a Cisco Catalyst 3750 that had a connection go out to a WAN. We had lost connection to our WAN branches, we moved the patch over to another port, and shortly afterwards the connections came back. I just started looking into the origional port and noticed the status being

GigabitEthernet1/0/24 is down, line protocol is down (err-disabled) <= Does the last bit in brackets mean that there has been a port failure?
thanks

 

[ADB100]

You should have had a message logged as to why the port error-disabled. There are various reasons it could happen:

bpduguard
etherchannel misconfiguration
dhcp-rate-limit
dtp flapping (trunking)
gbic invalid
link-flap
loopback
pagp-flap (etherchannel)
psecure-violation - port security violation
security-violation - 802.1x security violation
udld
unicast flooding

I suggest you have a look through the logs (I assume you have syslog or at least the internal buffer enabled?) and try to work out why it error disabled. Once you have this information you can look deeper as to the cause.

Andy

 

[vipergg]

To renable the port just do a no shut on the port , and like the previous poster said you need to check out why the port went errdisable . You can shut off this feature but that is kind of self defeating and I would leave that alone and figure out what caused it to errdisable in the first place .

 

[rn4it]

when I did a sh int I noticed just over 2000 late collisions and 2 interface resets. Could this do it? I'm still looking into some of the Items ADB100 sugested. I don't have alot of experience with Cisco switches, primarily work with Extreme gear. thanks for your assistance.

 

[vipergg]

If you are getting late collisions then it's likely thats what caused it to go errdisable , usually this is caused speed,duplex mismatches , both ends must match , auto-auto, 100/full etc . this sounds lie one end was set as half duplex and the other was full duplex .