Troubleshooting a group-interface (LACP port-channel) for partner ID and state changes.If there is a scenario where there is group-interface interface flapping (LACP link status going down/up), you may want to monitor the partner ID and state changes.
Flapping LACP group-interfaces can be difficult to troubleshoot, especially if the issues are happening intermittently. One way to do this is to use the attached script which runs a
'vethcfg list' every 2 seconds and pipes the output to a file on the APM. This can be helpful to aggressively watch the for state changes on a group interface including partner ID changes, MUX state, and LACP BPDU status.
In order to use this troubleshooting method you will need to do the following.
Create the veth_script.sh in the
/tftpboot/<vap-group_index>/root/ directory of an APM participating in the group-interface. Make the file executable.
1. Create the file:
touch veth_script.sh /tftpboot/fw_1/root/
2. Make the file executable:
chmod +x /tftpboot/fw_1/root/veth_script.sh
3. Add the following contents to the file and save it.:
while true; do
date >> vethcfg.txt
vethcfg list | head -3 >> vethcfg.txt
4. Test the script with the following command. You should see the MLT status scroll as the script continues echoing out the command.
tail -f vethcfg.txt
When the script is run you will see similiar results to:
Tue Mar 25 09:05:14 CDT 2014
S Port Agg A_KEY P_KEY P_SYS_PRI PARTNER_SYS MUX RECV PERIO A_STAT P_STAT