Err-disable on 3550 giga port

[ifabrizio]

Dear all,

I have one of my two giga ports on the 3550 in the following state:

C3550_Rack06#sh int gig 0/2

GigabitEthernet0/2 is down, line protocol is down (err-disabled)

Hardware is Gigabit Ethernet, address is 000e.d712.8532 (bia 000e.d712.8532)

MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Full-duplex, 1000Mb/s, link type is auto, media type is SX

output flow-control is off, input flow-control is off

ARP type: ARPA, ARP Timeout 04:00:00

Last input 6d21h, output 6d21h, output hang never

Last clearing of "show interface" counters 12w0d

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

283555797 packets input, 2679907662 bytes, 0 no buffer

Received 141184107 broadcasts (0 multicast)

0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog, 79286040 multicast, 0 pause input

0 input packets with dribble condition detected

116201518 packets output, 3720972769 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 babbles, 0 late collision, 0 deferred

0 lost carrier, 0 no carrier, 0 PAUSE output

0 output buffer failures, 0 output buffers swapped out

How I can determine the cause of this problem ?

Thanks & Regards

Igor.

[Prashanth Krishnappa]

Issue a sh log and the switch should have logged a message indicating why the port was err-disabled.

[ifabrizio]

I found the message :

Mar 24 11:09:00: gbic_security_remove_gbic() gbicEntryStorage is NULL (gbic_secu

rity_unique not initialized)

I have traied to serch the meaning of this message in the "Catalyst 3550 Multilayer Switch System Message Guide" but i didn't found it.

I suppose that this message is logged when I removed and insert again the Gbic.

[b-ulrich]

Hi,

Try this command. show interface gi0/2 status err-disabled. It should tell you why it is in that state.

[ifabrizio]

Hi,

Thank you for the precious help,I do the command above and the status is :

C3550_Rack06#show interface gi0/2 status err-disabled

Port Name Status Reason

Gi0/2 err-disabled loopback

What means this status ?

[Prashanth Krishnappa]

Loopback means a keepalive was looped back on the interface. Check out the following bug.

http://www.cisco.com/cgi-bin/Support/Bugtool/onebug.pl?bugid=CSCea46385

[miclacs13]

you can make a workaround if the port is always being diabled because of the loopback error and you dont have to shut/no shut the port.

issue the command for port autorecovey:

errdisable recovery cause loopback

errdisable recovery interval 30

[neclink]

it seems like excessive amount of broadcast traffic is causing the link to become disable. cheack for STP loop etc.