Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

Bronze

portchannel issue on C3750E

Hi all,

 

Just wanted to inform you on a strange thing we have seen. We have a 3-link portchannel to a NetApp device, configured for LACP.

Last night, one link went down and this brought down the whole portchannel. For some reasons Gi2/0/5 went to "not-connect / 100 Mbps speed"

 

This caused the other two ports to go into suspend mode (?):

 

%EC-5-CANNOT_BUNDLE2: Gi2/0/4 is not compatible with Gi2/0/5 and will be suspended (speed of Gi2/0/4 is 1000M, Gi2/0/5 is 100M)

%EC-5-CANNOT_BUNDLE2: Gi2/0/6 is not compatible with Gi2/0/5 and will be suspended (speed of Gi2/0/6 is 1000M, Gi2/0/5 is 100M)

 

First remark: a port that is in the "NOT-CONNECT" state in a portchannel should not influence other ports that are still up (even if there is a speed, or duplex mismatch), at least that is what i am thinking.

Is this a bug maybe ?

 

 

 

NOTE: Version 12.2(50)SE2

regards,

GN

 

Config of portchannel:

 

interface GigabitEthernet2/0/4
 switchport trunk encapsulation dot1q
 switchport trunk native vlan 999
 switchport trunk allowed vlan 312,610
 switchport mode trunk
 switchport nonegotiate
 load-interval 30
 no snmp trap link-status
 no mdix auto
 storm-control broadcast level 10.00
 storm-control action trap
 no cdp enable
 channel-group 47 mode active
 spanning-tree portfast trunk
 spanning-tree bpduguard enable

 

interface GigabitEthernet2/0/5
 switchport trunk encapsulation dot1q
 switchport trunk native vlan 999
 switchport trunk allowed vlan 312,610
 switchport mode trunk
 switchport nonegotiate
 load-interval 30
 no snmp trap link-status
 no mdix auto
 storm-control broadcast level 10.00
 storm-control action trap
 no cdp enable
 channel-group 47 mode active
 spanning-tree portfast trunk

 

interface GigabitEthernet2/0/6
 switchport trunk encapsulation dot1q
 switchport trunk native vlan 999
 switchport trunk allowed vlan 312,610
 switchport mode trunk
 switchport nonegotiate
 load-interval 30
 no snmp trap link-status
 no mdix auto
 storm-control broadcast level 10.00
 storm-control action trap
 no cdp enable
 channel-group 47 mode active
 spanning-tree portfast trunk
end

1 REPLY
New Member

I don't think it's a bug. It

I don't think it's a bug. It seems like all ports in a port-channel must be the same speed and duplex to be compatible.

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750x_3560x/software/release/12-2_53_se/configuration/guide/3750xscg/swethchl.html#wp1275881

If improperly configured, some EtherChannel ports are automatically disabled to avoid network loops and other problems. Follow these guidelines to avoid configuration problems:


Configure all ports in an EtherChannel to operate at the same speeds and duplex modes.

40
Views
0
Helpful
1
Replies
CreatePlease login to create content