In essence, at random moments of the day (0-4x/day, let's say), internet access for the wired devices behind the bridge becomes flaky and slow, to the point of being unusable until I restart the router. Access to the web interface as well as SSH remains largely intact (but is slowed down by DNS lookups failing).
The problem has existed since at least the official 18.x releases and exists despite nightly reboots, but I have recently noticed that ifup stabridge fixes it immediately. Still, I get a bit tired of issuing this fix multiple times a day, and it's certainly disturbing in video conferences.
How can I proceed investigating this?
I have noticed that issuing ifup stabridge randomly does not seem to negatively impact any open connections, so might it help to run that in a cron job every (minute/hour/...)?
Make sure you are following the up-to-date instructions of the current wiki, not the oldwiki.
Keep in mind that relay is a hack, not the optimal way to accomplish what you want, which would be WDS.
You could setup a script to probe some servers for http, dns, and ping and bump the stabridge in case something doesn't respond.
Thanks, good point. I did actually follow these new instructions initially, but Google first showed me the old ones when I was typing my post. I will double-check my setup and play around with ping-based triggers of ifup - thank you!
I have since noticed that these issues were triggered by an IPTV media receiver (MR401) starting scheduled recordings. ifup stabridge did not work reliably, but it turned out that ifup wifi (or whatever the exact command is) triggered a successful WiFi reconnection at least once. So it might not have been an issue with relayd at all.
That issue may also have been related to my switching off some tuning options in the modem router to "improve IPTV" (whatever it does exactly - might be IGMP Snooping in some shape or form).
We'll never find out though - I had to replace the router feeding that media receiver anyway, so I do not expect this issue to come back. (I basically switched the two routers with each other for a number of unrelated reasons.)