NPTv6 does not work with Track Interface

[STRUBartacus]

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Describe the bug

If NPTv6 is configured with a ULA prefix that is statically configured on a LAN interface with a GUA prefix via the “Track Interface” function, no translation takes place. If the same GUA prefix is configured manually, a correct translation takes place.

To Reproduce

• Firewall - NAT - NPTv6
• Change Track Interface from LAN to None
• Manually enter the LAN GUA prefix under “External IPv6 Prefix (target)”
• Save

Expected behavior

NPTv6 works correctly with the “Track Interface” function, so that the translation is automatically adjusted when the prefix is changed.

Environment

Software version used and hardware type if relevant, e.g.:

OPNsense 25.1.1-amd64
FreeBSD 14.2-RELEASE-p1
OpenSSL 3.0.16
Supermicro A2SDi-4C-HLN4F
Intel Atom Processor C3558

[funtowne]

Are you using the LAN as your NPTv6 translation target or WAN? I’ve used WAN without issue on a similar setup, for example.