Messages

Two dhcp6c instances? I thought we'd fixed that years ago! That used to be an issue in about 2017/18 but haven't seen it since. OK, try this, we're testing not fixing. Kill any dhcp6c instance and then leave the system alone for about thirty minutes.
From the shell restart dhcp6c, if you didn't do a full grep here's the command:

# /usr/local/sbin/dhcp6c -c /var/etc/dhcp6c.conf -p /var/run/dhcp6c.pid -D

I added the -D for full debug, does it now get the addresses?
The thirty minutes is important as it might be an ISP issue, I've seen it before.

If your IPv6 PD is going to change then just leave everything as tracking. If your address allocation changes then that will be advertised to your internal LAN by the dhcp6 server and radvd.  If you want a server on your LAN that can be accessed from the WAN then use a dns provider that supports dynamic DNS such as Cloudflare and use DDNS to update it. I've been there and got that t-shirt.

24 hours later and still solid.... bloody gremlins.

Now I'm completely baffled. I rebooted again and sat there running the ndp -r command and watching the timer countdown and reset, and reset, and reset....
It's working fine now.

I'm 99% sure the default route is stripped by a zero lifetime RA which the kernel reacts to by removing its default route and you can't even see it.

# ndp -r

should reveal that default route and if it's gone afterwards.

Funnily enough I just saw there is a "ndp -I xxx" which can set a default route via one particular interface if the route disappears for any reason but I've never tried it.


Cheers,
Franco

Interesting... I see this:
fe80::8ff:fe61:e32b%igb0 if=igb0, flags=MO, pref=medium, expire=2m59s
So that explains it.

But we don't force reloading the routes on RENEW either because ideally they would still be there.

I'm assuming this fixes the issue?

# /usr/local/etc/rc.routing_configure

So that would be:

https://github.com/opnsense/core/blob/8684443b6/src/etc/inc/interfaces.inc#L2957-L2963

But as noted the default route shouldn't be removed. DHCPv6 doesn't handle routes. We only do it "by accident".


Cheers,
Franco

Yep, that restores it.

But we don't force reloading the routes on RENEW either because ideally they would still be there.

I'm assuming this fixes the issue?

# /usr/local/etc/rc.routing_configure

So that would be:

https://github.com/opnsense/core/blob/8684443b6/src/etc/inc/interfaces.inc#L2957-L2963

But as noted the default route shouldn't be removed. DHCPv6 doesn't handle routes. We only do it "by accident".


Cheers,
Franco

I'll play later and let you know on this. But why is the default being removed is the question..

It's definitely NOT dhcp6c, I had already replaced the current version with one from quite a while back and the same thing happens. It's definitely a weirdo. I'll have a play this evening when I have the house to myself and see if I can narrow it down a bit more.

Here you go, dhcp6c seems OK to me. Something is removing the default route.


If I restart rtsold that will restore the route for a few minutes before it loses it again. If I restart dhcp6c then the route restores and holds, if I manually add the default route that also holds. Odd, very odd.

Let me have the dhcp6c debug log and I'll take a closer look.


Thanks,
Franco

The logs for dhcp6c look normal, all appears OK. As I said, restarting dhcp6c manually restores IPv6 functionality. However I've just done a netstat -r and there's no default route, restarting dhcp6c restores the default and it will stay that way until I reboot. Looking deeper now.




+++


So, the default route is set at boot and all is normal, the default route then disappears from the table at around 5 minutes after boot. Manually adding the route from the shell and leaving dhcp6c alone also restores IPv6 and then we are all good again.

I'd already tried that one. I'm leaning to it not being dhcp6c per say but some sort of race condition at boot. Killing dhcp6c and restarting it restores things. If it was dhcp6c I would expect the issue to happen again, it doesn't. I think because my ISP gives me a stupidly short lease time only 300 seconds that may be part of the issue. I'll play and see what I can find out.

I'm going to load it now. Seeing some weird IPv6 issues.


I'm running 25.1*. Yesterday I rebooted, everything came up OK, ten minutes later IPv6 stopped working, interfaces all have the correct addresses it just appears there's no route. dpinger is still saying all good. BTW, my ISP runs a five minute lease renewal, even though the address ranges are reserved!


I then killed and restarted dhcp6c and hey presto IPv6 started working and it's been working fine for 24 hours. I'll load the test dhcp6c and reboot, and see what happens.

++++


Same thing, five minutes after a reboot no route, restart dhcp6c all good again; may not be dhcp6c related but it's a pita. The only good thing is it appears I can cause the problem just by restarting opnsense.

Can confirm all is good. I've just done a fresh VM ( dev v25.1a_9 ) plus Franco's magic trick to get 1.9.1 and the dashboard looks as I intended.

It's still working on my system but the GUI is screwed. I'll see if I can find out what's broken it in 24.7.

I do my best for the community. But I would also be grateful to anyone who would leave me some "karma". thank you for the kind words.

Buckets of karma from me. :)