Re: Display of bridge member interfaces cut short - bug or intention?

On Wed, 20 Dec 2023 21:32:45 +0100
Michael Gmelin <freebsd@grem.de> wrote:

> On Wed, 20 Dec 2023 18:04:36 +0100
> "Patrick M. Hausen" <hausen@punkt.de> wrote:
> 
> > Hi all,
> > 
> > as some probably know we provide web hosting services and we use
> > jails for that.
> > 
> > On some particular host we have 255 vnet jails all of which are
> > connected to the external interface of the host - renamed to "inet0"
> > in our environment - via if_bridge(4) and all managed with iocage.
> > 
> > root@ph003:~ # grep inet0 /iocage/jails/vpro*/config.json|wc -l
> >      255
> > 
> > Of these 251 also have a second epair interface connected to a
> > private bridge named "priv1". These are used for connections to the
> > central database server which should not be exposed to the Internet.
> > 
> > root@ph003:~ # grep priv1 /iocage/jails/vpro*/config.json | wc -l
> >      251
> > 
> > While looking for a different problem to my great suprise I found
> > today that ifconfig truncates the list of member interfaces for both
> > bridge instances. And both to the same value of 102, although the
> > member numbers are (albeit slightly) different:
> > 
> > root@ph003:~ # ifconfig inet0|grep member:|wc -l
> >      102
> > root@ph003:~ # ifconfig priv1 | grep member: | wc -l
> >      102
> > 
> > All 255 jails are connected to the external network and perfectly
> > reachable from the Internet. That's why I conclude that the display
> > is wrong, not the bridge configuration.
> > 
> > What's happening here? Is this intentional or shall I file a bug
> > report?
> > 
> > More importantly: either way is this only cosmetic or will we hit
> > another unexpected limit of the number of interfaces that can be
> > members of a bridge any time soon?
> >   
> 
> Hi Patrick,
> 
> I could reproduce the issue and created a fix:
> https://reviews.freebsd.org/D43135
> 
> As far as I can tell the issue is cosmetic (unless, of course, you
> have automation based on libifconfig or the output of the ifconfig
> command).
> 
> Best
> Michael
> 

The fix landed in main[0] and will be MFCed to releng/13.2.

Cheers
Michael

[0]https://cgit.freebsd.org/src/commit/?id=3d36053ca6d6a17d408c8f92c504e6135dc9d8df


-- 
Michael Gmelin