Re: IPv6 networking problems in 14.3

I would try running the 14.3p2 system without the VLAN configuration and a direct connection to the upstream provider hardware (no switch) and see if the problem persists. That will determine if it’s a VLAN issue.

Tom

> On Sep 15, 2025, at 2:20 PM, Chris Ross <cross+freebsd@distal.com> wrote:
> 
> Okay.  Apologies to those who like the whole thread to be in each email, but
> I’m starting again here after a discovery.
> 
> I rebooted my router after copying the 14.1p5 kernel I was running earlier,
> and while the system failed to come up very well (due to 14.3 userland), I
> was able to manually start up dhcpcd, the same actual binary, and it was
> able to set up my IPv6 connectivity through my ISP just like before.  So
> there’s a regression here.  Or something subtle I need to change that I
> am so far missing.
> 
> Summary:
> When booted with FreeBSD 14.3-RELEASE-p2, dhcpcd gets an RA from my ISP,
> sends a NS, but never gets the NA response.  Therefore no outgoing packets
> ever get out.
> 
> % ndp -an | grep vlan0
> fe80::3e8a:b0ff:fe3e:4dce%vlan0      (incomplete)       vlan0 1s        I 
> fe80::6e8:e675:f359:3465%vlan0       a4:53:0e:79:b9:82  vlan0 permanent R
> % tail /var/log/dhcpcd.log
> Sep 15 14:03:14 [10047]: vlan0: soliciting an IPv6 router
> Sep 15 14:03:14 [10047]: vlan0: sending Router Solicitation
> Sep 15 14:03:14 [10047]: vlan0: Router Advertisement from fe80::3e8a:b0ff:fe3e:4dce
> Sep 15 14:03:14 [10047]: vlan0: executing: /usr/local/libexec/dhcpcd-run-hooks ROUTERADVERT
> Sep 15 14:03:17 [10047]: vlan0: fe80::3e8a:b0ff:fe3e:4dce is unreachable
> [...]
> 
> When booting with 14.1-RELEASE-p5, dhcpcd works as expected:
> 
> % cat 14.1-ndp-success
> fe80::3e8a:b0ff:fe3e:4dce%vlan0      3c:8a:b0:3e:4d:ce  vlan0 29s       R R
> fe80::a653:eff:fe79:b982%vlan0       a4:53:0e:79:b9:82  vlan0 permanent R 
> % (lines from dhcpcd.log)
> Sep 15 13:50:44 [57415]: vlan0: soliciting an IPv6 router
> Sep 15 13:50:44 [57415]: vlan0: sending Router Solicitation
> Sep 15 13:50:44 [57415]: vlan0: Router Advertisement from fe80::3e8a:b0ff:fe3e:4dce
> Sep 15 13:50:44 [57415]: vlan0: no global addresses for default route
> Sep 15 13:50:44 [57415]: vlan0: executing: /usr/local/libexec/dhcpcd-run-hooks ROUTERADVERT
> Sep 15 13:50:45 [57415]: vlan0: multicasting REBIND6 (xid 0x142ec7), next in 1.1 seconds
> Sep 15 13:50:45 [57415]: vlan0: REPLY6 received from fe80::3e8a:b0ff:fe3e:4dce
> Sep 15 13:50:45 [57415]: vlan0: renew in 3600, rebind in 5760, expire in 7200 seconds
> Sep 15 13:50:45 [57415]: vlan0: writing lease: /var/db/dhcpcd/vlan0.lease6
> Sep 15 13:50:45 [57415]: vlan0: delegated prefix 2600:4040:2c9d:5200::/56
> [...]
> Sep 15 13:50:45 [57415]: vlan0: adding default route via fe80::3e8a:b0ff:fe3e:4dce
> [...]
> Sep 15 13:50:45 [57415]: vlan0: executing: /usr/local/libexec/dhcpcd-run-hooks REBIND6
> Sep 15 13:50:45 [56455]: forked to background
> [...]
> 
> So.  What other information can I help gather?  I might be able to run tcpdump
> when I’m up in 14.1 kernel, though the system is kinda broken in a number of
> ways.  Let me know anything else I can gather to help track this regression.
> 
> -Chris
>