01-29-2009 06:57 AM - last edited on 03-25-2019 04:04 PM by ciscomoderator
Has anyone seen any issue with the 2960's where a member of the portchannel fails, causing the whole Portchannel to fail? We had a situation where both our uplinks failed. They were the only ports to go out, and they are both members of the same portchannel. The uplink switch just reported link and line proto down.. Upon a reboot, 1 of the interfaces can back up, the other stays in shutdown. I have seen this happen before, but not sure why both uplinks fail.
Model number WS-C2960-48TT-L
Version 12.2(25)SEE4
02-04-2009 02:18 PM
Begin troubleshooting Portchannel and trunking issues by verifying that you have completed following actions first:
⢠Use the show port-channel compatibility-parameters CLI command to determine PortChannel requirements.
⢠Ensure that one PortChannel is not connected to different sets of switches. PortChannels require point-to-point connections between the same set of switches.
⢠Verify that either side of a PortChannel is connected to the same number of interfaces.
⢠Verify that each interface is connected to the same type of interface on the other side.
⢠Verify that all required VSANS on a TE port are in the allowed-active VSAN list.
The following commands may be useful in troubleshooting PortChannel and trunking:
⢠show port-channel compatibility-parameters
⢠show port-channel summary
⢠show port-channel database
⢠show port-channel consistency detail
02-04-2009 07:20 PM
Can you post the config?
02-05-2009 05:56 AM
Here is the config. It has run fine for 1.5 years, and all of a sudden both uplinks failed. Reboot brought one uplink back, 2nd stays in permanent shutdown:
interface Port-channel1
description Po41
switchport trunk allowed vlan 1,115,116
switchport mode trunk
load-interval 30
spanning-tree bpdufilter enable
interface GigabitEthernet0/1
description Fa1/0/41
switchport trunk allowed vlan 1,115,116
switchport mode trunk
load-interval 30
channel-group 1 mode passive
spanning-tree bpdufilter enable
interface GigabitEthernet0/2
description Fa2/0/41
switchport trunk allowed vlan 1,115,116
switchport mode trunk
load-interval 30
channel-group 1 mode passive
spanning-tree bpdufilter enable
02-05-2009 06:04 AM
How is the other end configured ?
02-05-2009 06:18 AM
interface Port-channel41
description Po1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1,115,116
switchport mode trunk
load-interval 30
spanning-tree bpduguard enable
spanning-tree link-type point-to-point
spanning-tree guard root
end
interface FastEthernet1/0/41
description Gi0/1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1,115,116
switchport mode trunk
load-interval 30
channel-group 41 mode active
spanning-tree bpduguard enable
spanning-tree link-type point-to-point
spanning-tree guard root
end
interface FastEthernet2/0/41
description Gi0/2
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1,115,116
switchport mode trunk
load-interval 30
channel-group 41 mode active
spanning-tree bpduguard enable
spanning-tree link-type point-to-point
spanning-tree guard root
end
02-05-2009 06:07 AM
Hi,
What is the objective of configuring (spanning-tree bpdu filter enable) on the port channel and member ports??
Etherchannel provides redundancy and loadbalancing scheme but in One condition:
When Spanning-tree Instance treat both physical ports as Single Logicl Interface.
Configuring (BPDU filter enable), will preven BPDUs to be recieved by particular port, thus eleminating Spanning-tree functionality. Basically Disabling Spanning-tree on those Ports.
HTH
Mohamed
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