Re: review request: changing the default ifconfig(8) address format to CIDR

On 4 May 2024, at 16:34, Lexi Winter <lexi@le-fay.org> wrote:

> hi,
> 
> i've just submitted this PR:
> 
> https://github.com/freebsd/freebsd-src/pull/1216
> 
> which contains this commit:
> 
> commit 57d273c90ee1c17446236aba25ed0bd291c4f126 (HEAD -> lf/main, hemlock/lf/main)
> Author: Lexi Winter <lexi@le-Fay.ORG>
> Date:   Sat May 4 16:11:21 2024 +0100
> 
>    ifconfig(8): change default IP address format to 'cidr'
> 
>    'netmasks' haven't been used in IP networking for decades.  Change the
>    default address format for both IPv4 and IPv6 addreses in ifconfig(8) to
>    'cidr', which prints addreses in the format most users will be more
>    familiar with.
> 
>    The previous format is still available using -finet:hex or -finet6:numeric.
> 
> imp@ suggested i should ask arch@ and net@ about this, so here i am!
> 
> i understand there might be some backward-compat concerns with scripting
> here, but it's well past time this change was made, and anyone who
> really can't update their scripts can use ifconfig -f or
> $IFCONFIG_FORMAT to retain the old behaviour.

Do we need to care about supporting (/ do we currently support)
historical non-contiguous netmasks? At a glance the CIDR code doesn’t
handle that and will stop at the first 0, so changing to that by
default would break such setups.

Jess