[Asterisk-Dev] Multiple IP's For sip.

[Wolfgang S. Rupprecht]

tilghman at mail.jeffandtilghman.com (Tilghman Lesher) writes:
> On Tuesday 13 July 2004 14:07, Alberto Fernandez wrote:
> > Correct In sip.conf i bind the ip to 0.0.0.0 and it still doesnt let the
> > phones register. Im not folowing what you are trying to tell me. Please
> > elaborate.
> 
> I suspect I have already been too elaborate, and you actually want a more
> simplistic explanation:  the IP that Asterisk uses for SIP is based upon your
> route table.  If there is no explicit route for a destination, then Asterisk
> will use the device associated with the default route to specify that IP.

I think he might be seeing the same bug I see here, but haven't
bothered to track down further.  When Asterisk does a wildcard bind,
something screws up.  I solved it by the expediency of simply choosing
my outside interface and limiting asterisk to binding to that one.

If asterisk really does choose (or let the kernel choose) the source
IP based only on routing then I think I see the problem.  Asterisk
must take the src/dest addresses from the incoming packet and flip
them around (along with flipping the port numbers).  Doing otherwise
prevents the other side from associating the reply packet with its
query packet.

-wolfgang
-- 
Wolfgang S. Rupprecht                http://www.wsrcc.com/wolfgang/
openbsd amd64 http://www.wsrcc.com/wolfgang/ftp/asterisk-openbsd35.patch