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New Member

why would trunk port go in "err-disabled"? bpduguard isn't configured for this port.

Hi,

why would trunk port go in "err-disabled"? bpduguard isn't configured for this port. following is the port info.

sw#sh run int TenGigabitEthernet3/2

Building configuration...

Current configuration : 203 bytes

!

interface TenGigabitEthernet3/2

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 35-37, 42, 43

switchport mode trunk

no ip address

end

sw#sh int TenGigabitEthernet3/2

TenGigabitEthernet3/2 is down, line protocol is down (err-disabled)

  Hardware is C6k 10000Mb 802.3, address is b0fa.eb0f.3e84 (bia b0fa.eb0f.3e84)

  Description: UCS

  MTU 1500 bytes, BW 10000000 Kbit, DLY 10 usec,

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

1 ACCEPTED SOLUTION

Accepted Solutions
New Member

why would trunk port go in "err-disabled"? bpduguard isn't confi

Hello Gavin,

Before you go out and start replacing things, please have a log in your buffer. Lets see if you have a log entry still on your device which provides a clue as to why this port went down . (I assume it went down recently)

show log | i TenGigabitEthernet3/2

Have a log if you see anything.

If you dont have a log entry, please go to the affected interface and perform a shut and after a few seconds a no shut to see if the port comes up again.

I assume it will stay up for a short period and then retrun into err-disable state based on your recent statement. In any case, i hope that the    show log | i TenGigabitEthernet3/2

Regards

marQes

3 REPLIES
New Member

why would trunk port go in "err-disabled"? bpduguard isn't confi

Hello Gavin,

I have come across this problem a few times in the past. Most of my problems were encountered during install activies as I kept constantly disconnecting and moving the GBICs in and out but of course there are other reasons:

There are various reasons for the interface to go into errdisable. The reason can be:

  • Duplex mismatch
  • Port channel misconfiguration
  • BPDU guard violation
  • UniDirectional Link Detection (UDLD) condition
  • Late-collision detection
  • Link-flap detection
  • Security violation
  • Port Aggregation Protocol (PAgP) flap
  • Layer 2 Tunneling Protocol (L2TP) guard
  • DHCP snooping rate-limit
  • Incorrect GBIC / Small Form-Factor Pluggable (SFP) module or cable
  • Address Resolution Protocol (ARP) inspection
  • Inline power

The most common reason (for me anyhow) was donw to cable and GBIC so I assume this would be the best place to start.

Hope that helps

Regads

marQes

Hall of Fame Super Gold

why would trunk port go in "err-disabled"? bpduguard isn't confi

why would trunk port go in "err-disabled"

The answer to this question is the command "sh interface status err".

New Member

why would trunk port go in "err-disabled"? bpduguard isn't confi

Hello Gavin,

Before you go out and start replacing things, please have a log in your buffer. Lets see if you have a log entry still on your device which provides a clue as to why this port went down . (I assume it went down recently)

show log | i TenGigabitEthernet3/2

Have a log if you see anything.

If you dont have a log entry, please go to the affected interface and perform a shut and after a few seconds a no shut to see if the port comes up again.

I assume it will stay up for a short period and then retrun into err-disable state based on your recent statement. In any case, i hope that the    show log | i TenGigabitEthernet3/2

Regards

marQes

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