Re: Series of IPv6 Improvements

On 23.02.2026 at 10:12, Pouria Mousavizadeh Tehrani wrote:
> Hi,
>
> I've recently completed a series of changes focused on enhancing our 
> IPv6 stack, particularly around several important RFCs related to 
> Neighbor Discovery Protocol (NDP). These changes not only resolve 
> long-standing issues but also introduce new features that align with 
> modern networking standards.
>
> Here's an overview of what I've done:
> - Implemented Gratuitous Neighbor Discovery (RFC 9131 + RFC 4861 
> Section 7.2.6, which is also addresses one of the IPv6 deployment 
> issues in RFC 9898 Section 3.9.)
> - Implemented Optimistic DAD (RFC 4429)
> - Added support for delayed anycast and proxy addresses during 
> Neighbor Advertisement (RFC4861 7.2.7, + 7.2.8)
> - Introduced support for multiple PREF64 in Router Advertisement (RFC 
> 8781)
> - Implemented support for Route Information option (RFC 4191)
> - Simplified `nd6_ra_input()`
>
> While implementing the RFC 4191, I found out some of the route 
> expiration facilities are broken. So I fixed it myself:
> - rtnetlink(4): Add support for nexthop expiration in new route
> - route(8): Fixed the -expire argument when using netlink
> - netstat(1): Fixed expire column values in -r flag when using netlink
> - snl(3): Remove duplicate `rta_expires` member in the route parser
>
> These improvements should enhance our IPv6 capabilities significantly 
> and resolves many /* XXX */ comments + some long-standing issues like 
> lack of route option support (see PR263982).
>
> You can find those reviews here:
> https://reviews.freebsd.org/search/query/FpCNDQh8WgIb
>
> I'd appreciate any review or testing these proposed changes on 
> Phabricator.
>
Hi Pouria,

That’s really good news - it’s great to hear that our long-neglected 
IPv6 stack is finally getting some fixes and enhancements. It’s a bit 
unfortunate that the reviews are progressing so slowly, but that’s the 
reality sometimes.

Thank you very much for your work. I’ll keep my fingers crossed, and I 
promise to test at least some of these patches.

 From a tester’s perspective, it would be much easier if the changes 
were available as ready-to-apply commits (for example, something that 
could be applied with |git am|). Picking patches one by one from 
Phabricator and committing them manually into a local repository isn’t 
the most convenient workflow.

Thanks again for the effort - it’s very much appreciated.

Best regards,

-- 
Marek Zarychta