IPv6 regression, update 25.7 -> 25.7.2, WAN IF no longer reliably acquires IPv6

[Reiikz]

OPNSense is running completely virtualized on Proxmox using VirtIO type network adapters. Everything is working fine until I attempt to upgrade from 25.7 -> 25.7.2 through the web UI

Now (25.7.2) the WAN IF won't get an IPv6 reliably unlike with 25.7

WAN IF configuration:

I rolled back to an even older version using a proxmox snapshot and I noticed in OPNSense 24.7.12 that this option "Use IPv4 connectivity" I needed because that's how my ISP hands out IPv6 is now missing from Point to Point configuration in OPNSense 25.7.2 and 25.7

OPNSense 24.7.12 screenshot of relevant setting

Additionally weird is that after the upgrade to 25.7.2 IPv6 still works and My DHCPv6 server still hands out IPv6 to the LANs. However I need the WAN IF to have an IPv6 as well for the sake of other infrastructure but I can't seem to get it get one now.

The issue seems to be slightly intermitent tending to just not work most of the time?

I saw it get an IPv6 once. So far.

At the moment I will revert back to 25.7.

I attaching the log from https://opnsense/ui/diagnostics/log/core/system filtered by "WAN"

system.log

Working OPNSense verion:

Broked OPNSense version:

Let me know if I can provide any further information.

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[fichtner]

"Use IPv4 connectivity" has been removed from the GUI and is now set by default for a while now. I don't see any changes in 25.7 to 25.7.2 either that change interface or boot code that would explain this. Timing differences in the boot sequence may exist due to performance improvements in config.xml reading, but that would also mean the IPv6 acquire timing is circumstantial at best.

Cheers, Franco

[Reiikz]

I'm sorry for messing with the issue status the webpage jerked and I'm on mobile.

I was able to reproduce the issue in a different manner. I had since added some more port forwarding on IPv4 and so I made a backup of the config just in case when I went to update to 24.7.5 to see if the issue had been solved. which is not.

Case and point I reverted the snapshot with Proxmox (OPNSense in on a Proxmox VM) and everything was fine,I went to restore the config backup I had made for this situation and behold the WAN's IPv6 was gone again without updating.

So there must be some bug in the configuration system that's causing this.

[Reiikz]

Now that I was able to find some time to mess with it.

I've updated to

OPNsense 25.7.9-amd64 FreeBSD 14.3-RELEASE-p5 OpenSSL 3.0.18

Upon further investigation I've found the WAN interface does get an IPv6 address eventually and it takes a seemingly random amount of time no less than 10 minutes. Worthy of note is that during this time where the WAN doesn't have an address ISC DHCPv6 is working correctly and IPv6 connectivity is fully functional.

It seems explicitly giving the WAN interface a prefix fixes the issue.

I will make another comment if this fails again in the comming days.