Re: setting net.link.bridge.member_ifaddrs=0 by default

> On 11 May 2025, at 02:52, Lexi Winter <[email protected]> wrote:
> 
> hello,
> 
> since commit 0a1294f6c610948d7447ae276df74a6d5269b62e we have a new
> sysctl, net.link.bridge.member_ifaddrs.  when set to 0, this has the
> following effects:
> 
> - an interface with an IP address cannot be added to a bridge
> 
> - an interface inside a bridge cannot be configured with an IP address
> 
> - the system will not consider Ethernet frames addressed to link-level
>  addresses of members to be local traffic
> 
> i would like to propose that we set this to 0 by default in 15.0-RELEASE.
> 
> my reasoning for this is that having bridge members with an IP address
> assigned does not work, and has never worked, and it's clear from places
> where users ask for support (such as IRC) that many people run into this
> problem and do not understand what they're doing wrong, until someone
> explains that they should not assign an IP address to bridge members.
> 
> so, enabling this by default has clear benefits for usability (and also
> performance) as well as code simplification later when we can remove the
> relevant code, perhaps in 16.0R.
> 
> thoughts?

Good plan, make it so. 

It is likely to break existing setups, so we should land the change in main soon, and make sure there’s warnings in relevant places. 
A major release is the best place for such a change, and there’s not much point in postponing it to 16.0.

— 
Kristof