Hello all,
I'm currently running into some issues and the result is that we have mac-flapping between a port-channel and a normal uplink.
There's one AP connected to the switch using an Etherchannel, and the config is like this:
Switch#show run int P11
Building configuration...
Current configuration : 263 bytes
!
interface Port-channel11
switchport trunk native vlan 55
switchport mode trunk
logging event trunk-status
logging event bundle-status
logging event spanning-tree
logging event status
logging event subif-link-status
spanning-tree portfast edge trunk
end
The members of the port-channel are 2 ports (G1/0/13 - G1/0/14:
Switch#show run int G1/0/13
Building configuration...
Current configuration : 322 bytes
!
interface GigabitEthernet1/0/25
switchport trunk native vlan 55
switchport mode trunk
logging event trunk-status
logging event bundle-status
logging event spanning-tree
logging event status
spanning-tree portfast edge trunk
spanning-tree bpduguard enable
channel-protocol lacp
channel-group 1 mode active
end
Switch#show run int G1/0/26
Building configuration...
Current configuration : 322 bytes
!
interface GigabitEthernet1/0/14
switchport trunk native vlan 55
switchport mode trunk
logging event trunk-status
logging event bundle-status
logging event spanning-tree
logging event status
spanning-tree portfast edge trunk
spanning-tree bpduguard enable
channel-protocol lacp
channel-group 1 mode active
end
The issue starts when you connect the 2nd LAN interface of an Access point to this G1/0/14 interface.
After a couple of minutes, assuming broadcast traffic, things get started and network is deteriorating.
The logs show that there's mac flapping between the port-channel & the uplink to the core switch:
testswitch#show int G1/0/25 etherchannel ~~~~~~~~~
Aug 29 15:12:23.385: %SW_MATM-4-MACFLAP_NOTIF: Host a44c.c891.ea2f in vlan 1 is flapping between port Po11 and port Gi1/0/48
Aug 29 15:12:23.627: %SW_MATM-4-MACFLAP_NOTIF: Host 0050.5683.255d in vlan 1 is flapping between port Po11 and port Gi1/0/48
Aug 29 15:12:23.668: %SW_MATM-4-MACFLAP_NOTIF: Host 0017.9a54.f1b9 in vlan 1 is flapping between port Po11 and port Gi1/0/48
Aug 29 15:12:23.668: %SW_MATM-4-MACFLAP_NOTIF: Host 0050.56aa.7656 in vlan 1 is flapping between port Po11 and port Gi1/0/48
It only happens when we change the native vlan of the Access point to be VLAN 55 instead of VLAN1
We need to do this, because otherwise we have other issues with a SSID.
I have configured STP and the root is configured with Prio 0.
I've read that this could be due to misconfiguration with spanning-tree, but I don't see what we've could have configured wrong?
If we try the same setup, use the same etherchannel, between 2 switches, we don't see this issue.
When we don't use the Access Point I mean, the issues don't show.
This would rule out the fact that we might have misconfigured something.
I'm struggling with this for some time now and I'm wondering if this could be a bug or not?
Since you can find somewhat same issues:
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCut87285/?rfs=iqvred
And we have changed the firmware already a couple of times:
Cisco IOS Software, C2960X Software (C2960X-UNIVERSALK9-M), Version 15.2(2)E5, RELEASE SOFTWARE (fc2)
System image file is "flash:/c2960x-universalk9-mz.152-2.E5/c2960x-universalk9-mz.152-2.E5.bin"
Cisco IOS Software, C2960X Software (C2960X-UNIVERSALK9-M), Version 15.2(2)E6, RELEASE SOFTWARE (fc2)
System image file is "flash:/c2960x-universalk9-mz.152-2.E6/c2960x-universalk9-mz.152-2.E6.bin"
Cisco IOS Software, C2960X Software (C2960X-UNIVERSALK9-M), Version 15.2(2)E7, RELEASE SOFTWARE (fc2)
System image file is "flash:/c2960x-universalk9-mz.152-2.E7/c2960x-universalk9-mz.152-2.E7.bin"
Kind regards,
Gerrit
