some 2960S switch ports led turn amber even without cable connection

[SaulVilca]

Hi,

Hello. Due to a likely NIC problem, after connecting my laptop to a port on the 2960S (IOS 12.2.55(SE5)) switch, the led turns amber even after disconnecting the cable.

but when I restart the computer is restored to that port connectivity.

anyone know if this is a bug, or a problem with the switch, appreciate your support to resolve the incident.

Regards,

[Bilal Nawaz]

Hello, Most likely that the port is going through the spanning-tree phases of listening, learning, forwarding.

Please see this: https://learningnetwork.cisco.com/docs/DOC-10936

The reason why it may work when you restart you laptop/pc is because the port goes through normal stages, but when it's finished, by that time your laptop would have booted up.

You can make this process faster by using the spanning-tree portfast command under the interface.

Please see: http://m.dummies.com/how-to/content/spanning-tree-protocol-stp-and-portfast.html

If it never goes to forwarding (green) then you have a problem somewhere.

It's strange that it stays amber though...

Even when you're not connected physically.
Could you show us the running config of the interface please:

Show run interface fax/x

And a
Show interface Fax/x
Before and after you have plugged in and unplugged.

Hope this helps

Sent from Cisco Technical Support iPhone App

[SaulVilca]

Thanks for the response

copy the current serial port settings, I'm wrong in writing the issue is resolved by restarting the switch, because the led turns amber even after disconnecting the cable.

interface GigabitEthernet1/0/41

description en revision (ambar)

switchport access vlan 302

switchport mode access

switchport nonegotiate

switchport voice vlan 110

spanning-tree portfast

Regards,

[glen.grant]

On the switch do a "show interface status" and see if the switch is putting the port into a "err-disable" status .  If so then would be fixed by either a switch power off or a "shut then no shut of the port .

[SaulVilca]

Thanks for the response

The port is noconnected state and there is no cable connected but the switch port LED is in amber,
not sure if this related to the bug CSCtr79337.

Regards,

[Leo Laohoo]

Amber?

Can you kindly post the following output:

1.  sh interface status err; and

2.  sh post

[SaulVilca]

Thanks for the response,

I have only the command output "show interfaces gi 1/0/41" before rebooting the switch. I have seen this behavior in other switch, yet I can determine if it was due to the user's network card or cabling problems

GigabitEthernet1/0/41 is down, line protocol is down (notconnect)

  Hardware is Gigabit Ethernet, address is ccd5.3906.69a9 (bia ccd5.3906.69a9)

  Description: en revision (ambar)

  MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,

     reliability 252/255, txload 1/255, rxload 1/255

  Encapsulation ARPA, loopback not set

  Keepalive set (10 sec)

  Auto-duplex, Auto-speed, media type is 10/100/1000BaseTX

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

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

  Last input 1d08h, output 23:22:08, output hang never

  Last clearing of "show interface" counters never

  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 8

  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

     102827 packets input, 26316902 bytes, 0 no buffer

     Received 7435 broadcasts (3047 multicasts)

     0 runts, 12 giants, 0 throttles

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

     0 watchdog, 3047 multicast, 0 pause input

     0 input packets with dribble condition detected

     797759 packets output, 135259122 bytes, 0 underruns

     0 output errors, 32 collisions, 3 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

Regards,

[Leo Laohoo]

GigabitEthernet1/0/41 is down, line protocol is down (notconnect)
  reliability 252/255, txload 1/255, rxload 1/255

Gotcha!  You've got a cable problem.  You can determine WHERE the cable fault is if you run a TDR test.