DNS and internet dropping

[storkinsj]

I'm having a strange issue and I just need some tips on how to debug it.

I have a dual WAN AX11000 router running 3004.388.5.

I have a SanDisk extreme USB drive configured for JFFS that contains some dnsmasq configuration. Diversion is installed but currently off as it was "beating" on the usb drive and I think it caused problems in the past with reads/writes.

I am using the 1Gb WAN for primary (this goes to another router with pass-thru) and ethernet port 4 for secondary wan (uses the apartment building WAN).

I have a routing setup; half the devices (192.168.4.0/24) use primary WAN and the other half (192.168.0.0/24) use the secondary.

When I have it configured to only use the primary WAN (cold standby for secondary), it works seemlessly for months on end.

When I turn on load balancing to enable the secondary WAN and actually enable routing, it works great for almost 24 hours and then DNS fails.

The strange thing is when DNS fails, I also can not connect (ping 1.1.1.1) to the internet from a router ssh session. It seems like "everything is down".

I can fix this by going to the WAN settings and force-resetting the DNS to any other entry (i.e. google). I can even set it back to what I normally use (quad 9). After that, it just starts working again, including the pings!

There is no kind of normal about this. I am thinking that it probably relates back to the JFFS and USB since I had an outage related to that once, but I guess I need to figure out how to look through the logs correctly to see what's going on. I don't see anything weird in the syslog but I just bumped it up to "debug" from "notice" to see if I get more next failure.

Thanks for any ideas.

 

[ColinTaylor]

JFFS is part of the router's internal storage, it's not on the USB drive.

 

[storkinsj]

Noted; not sure what I put the drive on there for at this point but I felt like jffs could be done that way. I know that originally it was completely not doable.

The main thing is figuring out how to debug the problem. If jffs / usb is a red herring glad to hear that.

 

[storkinsj]

Well,
My DNS is a bit more stable; however I now experience complete loss of DNS every time the router reboots.

I actually had the router set to reboot once a week ; now I had to turn this off.

The fix is always the same: go into WAN DNS setting, click "assign" and change the DNS setting to something, and then change it back.

Only after this force resetting of DNS settings will DNS resume working on Dual WAN.