Source
r/Fios•
jandrese

FiOS link flapping every 5 minutes

My FIOS link was just upgraded to IPv6 (yay!) but it has started flapping every 5 minutes. I'm guessing there is some other bit of configuration I need to do to avoid this, but I have no idea what it could be.

I very much doubt it is a hardware issue, the flapping happens far too regularly:

Jun  8 20:50:01 FreeBSD kernel: igb0: link state changed to DOWN
Jun  8 20:50:04 FreeBSD kernel: igb0: link state changed to UP
Jun  8 20:55:01 FreeBSD kernel: igb0: link state changed to DOWN
Jun  8 20:55:04 FreeBSD kernel: igb0: link state changed to UP
Jun  8 21:00:01 FreeBSD kernel: igb0: link state changed to DOWN
Jun  8 21:00:04 FreeBSD kernel: igb0: link state changed to UP
Jun  8 21:05:01 FreeBSD kernel: igb0: link state changed to DOWN
Jun  8 21:05:04 FreeBSD kernel: igb0: link state changed to UP
Jun  8 21:10:01 FreeBSD kernel: igb0: link state changed to DOWN
Jun  8 21:10:04 FreeBSD kernel: igb0: link state changed to UP
Jun  8 21:15:01 FreeBSD kernel: igb0: link state changed to DOWN
Jun  8 21:15:04 FreeBSD kernel: igb0: link state changed to UP
Jun  8 21:20:01 FreeBSD kernel: igb0: link state changed to DOWN
Jun  8 21:20:04 FreeBSD kernel: igb0: link state changed to UP
Jun  8 21:25:01 FreeBSD kernel: igb0: link state changed to DOWN
Jun  8 21:25:04 FreeBSD kernel: igb0: link state changed to UP
Jun  8 21:30:01 FreeBSD kernel: igb0: link state changed to DOWN
Jun  8 21:30:04 FreeBSD kernel: igb0: link state changed to UP
Jun  8 21:35:01 FreeBSD kernel: igb0: link state changed to DOWN
Jun  8 21:35:04 FreeBSD kernel: igb0: link state changed to UP
Jun  8 21:40:01 FreeBSD kernel: igb0: link state changed to DOWN
Jun  8 21:40:04 FreeBSD kernel: igb0: link state changed to UP
Jun  8 21:45:01 FreeBSD kernel: igb0: link state changed to DOWN
Jun  8 21:45:04 FreeBSD kernel: igb0: link state changed to UP
Jun  8 21:50:01 FreeBSD kernel: igb0: link state changed to DOWN
Jun  8 21:50:04 FreeBSD kernel: igb0: link state changed to UP
Jun  8 21:55:01 FreeBSD kernel: igb0: link state changed to DOWN
Jun  8 21:55:04 FreeBSD kernel: igb0: link state changed to UP
Jun  8 22:00:01 FreeBSD kernel: igb0: link state changed to DOWN
Jun  8 22:00:04 FreeBSD kernel: igb0: link state changed to UP

Unfortunately I can't find any diagnostics other than the connection dropping and coming back. It's entirely unclear what the root issue is to me.

Posted Jun 9, 2022, 3:34 AM UTC

55
jandreseOP•

Update: it was my fault after all. I found a forgotten watchdog process that was triggering because my HE.net tunnel was down.

4
JE163•

Thanks for sharing

2
ifthenelse•

I don't know if this is the same issue but Intel cards and the Verizon ONT's don't get along well. Try disabling hardware checksum offloading or try a different NIC.

3
gadgetboyj•

Are these logs from your router or from a workstation? If this is your router, have you tried power cycling the ONT? If this is a workstation, have you tried rebooting the router? It looks like the physical link state is changing, so I would definitely start with a power cycle, remove power fully if you can.

2
jandreseOP•

This is from the router connected to the ONT. I've tried power cycling both to no effect. 1 second after every 5 minutes (regardless of when they were booted) the link drops for 3 seconds.

I have no idea what Verizon wants.

1