Re: epair(4)

On 17 May 2025, at 7:15, Konstantin Belousov wrote:
> On Fri, May 16, 2025 at 10:38:58PM +0200, Kristof Provost wrote:
>> As Lexi pointed out in another e-mail: users should assign addresses to the bridge, never to bridge member interfaces.
>>
>
> Could you, please, also explain why this is the requirement, besides stating
> that the configuration is invalid?
>
It breaks multicast. Multicast traffic we’re subscribed to will not arrive unless our address is assigned to the bridge rather than the member interfaces. You mostly get away with that for IPv4 (which is often worse, because “Everything works except for X”), but it totally breaks IPv6.

See also
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=243554
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=247912#c6

There’s also a fairly decent performance improvement, at least in the tests Ivy has done. That’s a secondary consideration, but nice to have anyway.

—
Kristof