This website uses cookies. By clicking Accept, you consent to the use of cookies. Click Here to learn more about how we use cookies.
Accept
Reject
Help
cancel
Turn on suggestions
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
Showing results for 
Search instead for 
Did you mean: 

Flapping on Cisco switch when connected to Extreme Wireless Controller lag2 ports

Flapping on Cisco switch when connected to Extreme Wireless Controller lag2 ports

Steve_Ballantyn
Contributor

‎03-09-2016 02:50 PM

On my C5210 Extreme Wireless Controller, I have a lag2 which consists of esa2 and esa3. These are filled with fiber SFP's which connect to a Cisco C3750 (ports 51, and 51 on a 48 port switch).

On my Cisco side, I am seeing MAC flapping between the two lag ports ...
.Mar 9 14:52:19.071: %SW_MATM-4-MACFLAP_NOTIF: Host 001e.67d0.5b54 in vlan 72 is flapping between port Gi1/0/52 and port Gi1/0/51.Mar 9 14:52:23.374: %SW_MATM-4-MACFLAP_NOTIF: Host 00cd.fe77.18c7 in vlan 190 is flapping between port Gi1/0/51 and port Gi1/0/52
.Mar 9 14:52:44.673: %SW_MATM-4-MACFLAP_NOTIF: Host 4088.05bf.4a47 in vlan 190 is flapping between port Gi1/0/51 and port Gi1/0/52
.Mar 9 14:52:48.850: %SW_MATM-4-MACFLAP_NOTIF: Host 001e.67d0.5b54 in vlan 72 is flapping between port Gi1/0/52 and port Gi1/0/51
.Mar 9 14:52:52.650: %SW_MATM-4-MACFLAP_NOTIF: Host 00cd.fe77.18c7 in vlan 190 is flapping between port Gi1/0/51 and port Gi1/0/52
.Mar 9 14:53:05.477: %SW_MATM-4-MACFLAP_NOTIF: Host 4088.05bf.4a47 in vlan 190 is flapping between port Gi1/0/51 and port Gi1/0/52
.Mar 9 14:53:22.128: %SW_MATM-4-MACFLAP_NOTIF: Host 00cd.fe77.18c7 in vlan 190 is flapping between port Gi1/0/51 and port Gi1/0/52
.Mar 9 14:53:34.786: %SW_MATM-4-MACFLAP_NOTIF: Host 4088.05bf.4a47 in vlan 190 is flapping between port Gi1/0/51 and port Gi1/0/52
.Mar 9 14:53:46.212: %SW_MATM-4-MACFLAP_NOTIF: Host 6045.bdcc.f4c0 in vlan 76 is flapping between port Gi1/0/51 and port Gi1/0/52
Here is what my Cisco config looks like ...
interface Port-channel2 description EXTREME WIRELESS PORT-CHANNEL
switchport trunk encapsulation dot1q
switchport mode trunk
interface GigabitEthernet1/0/51 description EXTREME WIRELESS CONTROLLER LAG2
switchport trunk encapsulation dot1q
switchport mode trunk
channel-group 2 mode on
!
interface GigabitEthernet1/0/52
description EXTREME WIRELESS CONTROLLER LAG2
switchport trunk encapsulation dot1q
switchport mode trunk
channel-group 2 mode on
From what I am reading, this is usually caused by an etherchannel protocol mis-match. I am assuming that both sides are using LACP. But is that not the case? I can change that on my Cisco side. I have tried on, desireable, and passive. But they all give me the same problem.
switch-serveroomb(config-if)#channel-group 2 mode ? active Enable LACP unconditionally
auto Enable PAgP only if a PAgP device is detected
desirable Enable PAgP unconditionally
on Enable Etherchannel only
passive Enable LACP only if a LACP device is detected

0 Kudos
8 REPLIES 8

Jeremy_Gibbs
Contributor
In response to Jeremy_Gibbs

‎03-09-2016 06:17 PM

Can you post some show spantree stuff:

show spanning-tree summary

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750/software/release/12-2_55_se/commmand...
0 Kudos

Steve_Ballantyn
Contributor
In response to Jeremy_Gibbs

‎03-09-2016 06:17 PM

Unfortunately, I am still flapping with this setting.
0 Kudos

Mel78__CISSP__E
New Contributor III

‎03-09-2016 03:00 PM

You should have use passive.

mode "on" is neither PAgP or LACP.

Refer to Cisco description below

EtherChannel On ModeEtherChannel on mode can be used to manually configure an EtherChannel. The on mode forces a port to join an EtherChannel without negotiations. The on mode can be useful if the remote device does not support PAgP or LACP. In the on mode, a usable EtherChannel exists only when the switches at both ends of the link are configured in the on mode.

Ports that are configured in the on mode in the same channel group must have compatible port characteristics, such as speed and duplex. Ports that are not compatible are suspended, even though they are configured in the on mode.

0 Kudos

Steve_Ballantyn
Contributor
In response to Mel78__CISSP__E

‎03-09-2016 03:00 PM

Hello Wong,

Using passive on these two ports gives me the same flapping issue.
interface GigabitEthernet1/0/51 description EXTREME WIRELESS CONTROLLER LAG2
switchport trunk encapsulation dot1q
switchport mode trunk
channel-group 2 mode passive
!
interface GigabitEthernet1/0/52
description EXTREME WIRELESS CONTROLLER LAG2
switchport trunk encapsulation dot1q
switchport mode trunk
channel-group 2 mode passive
!switch-serveroomb#term monswitch-serveroomb#
.Mar 9 17:14:40.623: %SW_MATM-4-MACFLAP_NOTIF: Host 6045.bdcc.f4c0 in vlan 76 is flapping between port Gi1/0/51 and port Gi1/0/52
.Mar 9 17:14:50.362: %SW_MATM-4-MACFLAP_NOTIF: Host a866.7fb1.a11c in vlan 190 is flapping between port Gi1/0/51 and port Gi1/0/52
.Mar 9 17:14:52.081: %SW_MATM-4-MACFLAP_NOTIF: Host 3412.98ef.72a0 in vlan 76 is flapping between port Gi1/0/51 and port Gi1/0/52
.Mar 9 17:15:11.526: %SW_MATM-4-MACFLAP_NOTIF: Host 6045.bdcc.f4c0 in vlan 76 is flapping between port Gi1/0/51 and port Gi1/0/52
.Mar 9 17:15:20.343: %SW_MATM-4-MACFLAP_NOTIF: Host a866.7fb1.a11c in vlan 190 is flapping between port Gi1/0/51 and port Gi1/0/52
.Mar 9 17:15:20.963: %SW_MATM-4-MACFLAP_NOTIF: Host 3412.98ef.72a0 in vlan 76 is flapping between port Gi1/0/51 and port Gi1/0/52

0 Kudos
GTM-P2G8KFN