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Router reboot adds unwanted 'conntrack-sync mcast-group ''' line to configuration
Open, Requires assessmentPublicBUG


I use conntrack-sync at home between my two Vyos routers, this gives great failover and all my sessions just keep working. I love it, it's a great Vyos feature.

I recently realised however that the multicast traffic it uses was also forwarding onto my Wireless APs creating a lot of unnecessary multicast traffic. So I moved to using the Unicast (UDP) conntrack-sync feature, which works just as well.

The problem is, if I reboot my router, the mcast config re-appears in the configuration.


tim@ferrari-backup:~$ show configuration commands | match mcast
tim@ferrari-backup:~$ reboot
Are you sure you want to reboot this system? [y/N] y
Connection to closed by remote host.
Connection to closed.
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Last login: Fri Nov 20 13:07:11 2020 from
tim@ferrari-backup:~$ show configuration commands | match mcast
set service conntrack-sync mcast-group ''

You can see that after the reboot, the mcast-group command has re-appeared in the config.

The whole conntrack-sync config now looks like:

tim@ferrari-backup:~$ show configuration commands | match conntrack-sync
set service conntrack-sync accept-protocol 'tcp,udp,icmp'
set service conntrack-sync disable-external-cache
set service conntrack-sync event-listen-queue-size '8'
set service conntrack-sync expect-sync 'all'
set service conntrack-sync failover-mechanism vrrp sync-group 'failover-group'
set service conntrack-sync interface eth1 peer ''
set service conntrack-sync mcast-group ''
set service conntrack-sync sync-queue-size '8'

Conntrack sync is still using the UDP peer:

tim@ferrari-backup:~$ show conntrack-sync statistics

<snip snip>

UDP traffic (active device=eth1):
               57392 Bytes sent              3981432 Bytes recv
                1359 Pckts sent                49281 Pckts recv
                   0 Error send                    0 Error recv

so it appears that the bug is mostly cosmetic.

However, I don't think rebooting the router should cause additional lines of configuration to be added to the router.



Difficulty level
Unknown (require assessment)
Why the issue appeared?
Will be filled on close
Is it a breaking change?
Unspecified (possibly destroys the router)

Event Timeline

tjh created this task.Fri, Nov 20, 12:20 AM
pasik added a subscriber: pasik.Fri, Nov 20, 7:47 AM