Multi-link LACP group interface flapping on a VAP group running any routing protocolA VAP group configured for multi-link LACP group interface and running dynamic routing protocol may experience system instability.
The following messages are repeatedly seen in the /var/log/messages file. <snip> Jul 8 18:08:31 test_1 kernel: veth: port 2,1 stop distributing. Jul 8 18:08:31 test_1 kernel: veth: port 2,2 stop distributing. Jul 8 18:08:31 test_1 kernel: veth: port 2,3 stop distributing. Jul 8 18:08:31test_1 cbsvapcfgd[31880]: [I] Removed alias inside:1 for cct 1021 - 192.168.1.1 Jul 8 18:08:31 test_1 cbsvapcfgd[31880]: [I] Removed alias outside:1 for cct 1071 - 172.16.1.1
Jul 8 18:08:35 test_1 cbsinitd[2541]: [I] daemon 'daemon.cbshagentd' (prcnam:cbshagentd) is running with 2 pid(s) Jul 8 18:08:36 test_1 cbsinitd[2541]: [I] starting daemon 'daemon.ospfd' using command '/etc/rc.d/init.d/ospfd start' Jul 8 18:08:36 test_1 cbsinitd[2541]: [I] starting daemon 'daemon.nsm' using command '/etc/rc.d/init.d/nsm start
Jul 8 18:08:36 test_1 kernel: veth: port 2,4 start distributing. Jul 8 18:08:37 test_1 kernel: veth: port 2,3 start distributing. Jul 8 18:08:37 test_1 kernel: veth: port 2,2 start distributing.
Cause
The LACP flaps if the routing protocol logs are 2GB in size and, when the routing protocol daemon is started, it is unable to write to this log.
Resolution
Workaround
Delete the logfile and restart the routing protocol.
For example To delete the ospfd.log from the test VAP group:
From the CPM:
rsh test_1 cd /crossbeam/logs rm ospfd.log
To prevent the routing protocol logs growing to 2GB in size over time, rotate the log files daily. Refer to articles 000006066 and 000006067 How-to-rotate-default-routing-protocol-logs?