I've been having this issue since I first got my R7800 with OpenWRT 18.06, and now I'm on 19.07.6 and am still getting it.
In short, sometimes I notice my internet connection is gone, and I find that my router is not responsive. I cannot log onto the LuCI interface or to the router through SSH. I can sometimes access other devices on my local network, so it seems like the WAN is down. The only way I can fix this is to completely restart the router from power.
The problem is, I can't find any logs indicating unusual behavior. I have logs in logread only for the last time I rebooted the device. Below are some of the logs - Jan 21 is the last time I restarted the device.
Thu Jan 21 12:07:00 2021 daemon.notice netifd: Interface 'wan6' is now up
Thu Jan 21 12:07:00 2021 daemon.info dnsmasq[638]: reading /tmp/resolv.conf.auto
Thu Jan 21 12:07:00 2021 daemon.info dnsmasq[638]: using local addresses only for domain test
Thu Jan 21 12:07:00 2021 daemon.info dnsmasq[638]: using local addresses only for domain onion
Thu Jan 21 12:07:00 2021 daemon.info dnsmasq[638]: using local addresses only for domain localhost
Thu Jan 21 12:07:00 2021 daemon.info dnsmasq[638]: using local addresses only for domain local
Thu Jan 21 12:07:00 2021 daemon.info dnsmasq[638]: using local addresses only for domain invalid
Thu Jan 21 12:07:00 2021 daemon.info dnsmasq[638]: using local addresses only for domain bind
Thu Jan 21 12:07:00 2021 daemon.info dnsmasq[638]: using local addresses only for domain lan
Thu Jan 21 12:07:00 2021 daemon.info dnsmasq[638]: using nameserver redacted
Thu Jan 21 12:07:00 2021 daemon.info dnsmasq[638]: using nameserver redacted
Thu Jan 21 12:07:00 2021 daemon.info dnsmasq[638]: using nameserver redacted
Thu Jan 21 12:07:00 2021 daemon.info dnsmasq[638]: using nameserver redacted
Thu Jan 21 12:07:00 2021 daemon.info dnsmasq[638]: using nameserver redacted
Thu Jan 21 12:07:00 2021 user.notice firewall: Reloading firewall due to ifup of wan6 (eth0.2)
Tue Jan 26 19:39:42 2021 authpriv.info dropbear[2144]: Child connection from redacted
Tue Jan 26 19:39:43 2021 authpriv.notice dropbear[2144]: Password auth succeeded for 'root' from redacted
Nothing from before or when it went down. If it helps, here's my list of packages:
The only notable thing I'm running on my router is a dynamic DNS service. I'm running my own DHCP and DNS server on a LAN device, which the router points to.
I'd appreciate any pointers to help debug this and hopefully resolve it soon. Thank you very much!
I'm on 19.07.7 and I'm still getting this issue. logread still doesn't indicate anything noteworthy to me. The log output level is currently set to Debug - is there a way to get even more detailed logs?
This issue happens seemingly randomly. The router has been on for several months with absolutely no issues, and now I got this problem within a few days of each other.
I would sincerely appreciate any pointers to further debug this.
logs are stored in RAM buffer (to avoid flash writes), so if you really talk about router crash & reboot, the reasons do not get stored into log. The log after boot shows only the happenings after the reboot.
At this point it would probably makes sense to just try 21.02.0-rc1, before spending a lot of time on trying to debug 19.07.x. There have been considerable changes since 19.07.x (and more are pending, so testing a kernel 5.10/ DSA branch might be even more interesting).