[Bug 208001] After turning off the jail does not remove network routes

[Allan Jude]

On 2016-05-28 20:30, bugzilla-noreply at freebsd.org wrote:
> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=208001
> 
> --- Comment #5 from Jamie Gritton <jamie at FreeBSD.org> ---
> Yes, of course there are cases where something besides a /32 is appropriate -
> that is why jail(8) allows that.  However, as I mentioned it did appear that
> you had violated the specification that an alias should be on a non-conflicting
> netmask.
> 
> The fact remains that I am unable to reproduce your problem.  Perhaps I could
> if I had your entire configuration - all jails, all other network setup.
> 
> jail(8) simply calls ifconfig(8) with "alias" to add IP addresses, and with
> "-alias" to remove them - see the output of "jail -vc" and "jail -vr".  The
> jail will not be removed if the "ifconfig ... -alias" command fails, which
> implies that the command is succeeding.  Unless of course there actually is a
> bug in the way jail(8) is running this program.  My guess is the command is
> succeeding, but isn't removing some arp entry because the alias when
> incorrectly specified when it was created.
> 
> If it's clear (from "jail -v") that the correct ifconfig commands are being
> run, then this might be considered an ifconfig bug.  If the correct commands
> aren't being run, then it could be a jail bug.
> 


I think that is actually the problem

ifconfig -alias
only accepts the IP address, not with the CIDR.

#ifconfig lo0 alias 10.0.0.1/24
#ifconfig lo0 -alias 10.0.0.1/24
ifconfig: 10.0.0.1/24: bad value

you want to do just:
#ifconfig lo0 -alias 10.0.0.1

So jail(8) needs to strip the /24 off when passing it to ifconfig -alias

-- 
Allan Jude