Allowing routing table visibility in jails to make multiple IPs work properly

[Ian Smith]

On Fri, 3 Jan 2014 08:05:55 -0500, Alejandro Imass wrote:
 > On Fri, Jan 3, 2014 at 3:00 AM, Rudy (bulk) <crapsh at monkeybrains.net> wrote:
 > >
 > > I'm having issues when putting multiple IPs on a jail... one external, one
 > > internal (on a different vlan).  The source IP from the jail is always the
 > > first IP, so a solution is to use ipfw_nat to nat when using the internal
 > > vlan to the 'second ip'.  Ugly hack. and it doesn't work when there is an
 > > MTU difference between the vlans:
 > >
 > 
 > Greetings Rudy,
 > 
 > I had the same exact problem and found that the problem is natd.
 > Actually it is mentioned in natd's documentation.

Alejandro, hi,

can you point out where in natd(8) it indicates .. what exactly?

 > If you want to get rid of this problem you need to get rid of natd and
 > nat your jail traffic with some other means. Kernel nat should be a
 > solution but I've never gotten around to test if it actually solves
 > the problem. Please share if you find a way to fix this.

I may have missed it, but I've yet to see anyone report any functional 
differences between natd and ipfw_nat, ie of something working in one 
but not the other.  Both use the underlying libalias(3) after all.

cheers, Ian