[On 15/11/2020 16:02, Andrew Lunn wrote: > What might be interesting is running > > ip monitor > > and > > bridge monitor > > Look for neighbours being timed out do to inactivity.
Funny you write that! This afternoon I've narrowed it down although I still don't understand the 'why'. Watching on the 'good' (lab) and 'bad' (gateway) Mox devices I noticed that: # bridge -d -s mdb show 23: br-lan br-lan ff02::2 temp 257.05 23: br-lan br-lan ff05::2 temp 257.05 23: br-lan br-lan ff02::6a temp 257.05 23: br-lan br-lan ff02::1:ff77:2b20 temp 257.05 23: br-lan br-lan ff02::1:ff00:ffff temp 257.05 23: br-lan br-lan ff02::fb temp 257.05 23: br-lan br-lan ff02::1:ff00:0 temp 257.05 23: br-lan br-lan ff02::1:2 temp 257.05 23: br-lan br-lan ff05::1:3 temp 257.05 indicates that the entries time out on 'bad' but are reset to a high value on 'good' # bridge monitor on 'bad' reported: Deleted Deleted 23: br-lan br-lan ff02::2 temp Deleted Deleted 23: br-lan br-lan ff05::2 temp Deleted Deleted 23: br-lan br-lan ff02::6a temp Deleted Deleted 23: br-lan br-lan ff02::1:ff77:2b20 temp Deleted Deleted 23: br-lan br-lan ff02::1:ff00:ffff temp Deleted Deleted 23: br-lan br-lan ff02::fb temp Deleted Deleted 23: br-lan br-lan ff02::1:ff00:0 temp Deleted Deleted 23: br-lan br-lan ff02::1:2 temp Deleted Deleted 23: br-lan br-lan ff05::1:3 temp On the laptop I'm testing from (tcpdump always on the laptop): Using tcpdump I *think* enp2s0 (wired link direct into lan1 on 'good') always showed the laptop sending multicast listener report v2 packets on a regular cadence of about 60-100 seconds as well as the DHCPv6 solicit/renews and that cadence matched when the timers on the output of "bridge -d -s mdb show" reset to approximately 258. But for wlp4s0 (wifi to 'bad') the DHCPv6 solicit/renew didn't seem to be accompanied by multicast listener reports and the mdb timers expired. I need to re-affirm that tomorrow because I've got slightly lost attempting to compare multiple aspects on both 'good' and 'bad' and seem to be seeing inconsistent results. On the laptops we are using Xubuntu 20.04 amd64 with NetworkManager. I'll try to test from a range of different devices tomorrow in case this is only affecting staff laptops. Many thanks for the pointers.
