[Twisted-Python] UDP answer from different IP

[Justin Warren]

On Wed, 2006-04-05 at 07:08 +0200, Wolfgang Eichler wrote:
> It is as you describe (but on Windows, not Solaris):
> C:\>ipconfig
> Windows 2000 IP Configuration
> 
> Ethernet adapter Local Area Connection 2:
> 
>         Connection-specific DNS Suffix  . : ca.com
>         IP Address. . . . . . . . . . . . : 130.119.127.196
>         Subnet Mask . . . . . . . . . . . : 255.255.255.0
>         Default Gateway . . . . . . . . . : 130.119.127.1
> 
> Ethernet adapter Local Area Connection:
> 
>         Connection-specific DNS Suffix  . : ca.com
>         IP Address. . . . . . . . . . . . : 130.119.127.127
>         Subnet Mask . . . . . . . . . . . : 255.255.255.0
>         Default Gateway . . . . . . . . . : 130.119.127.1

Hmm. I've encountered this kind of issue under Solaris with IPMP in that
if you have more than one active interface on a given network, you can't
easily predict which IP address the OS will choose for outbound packets.
I'm not familiar with the Windows selection algorithm.

Is the SNMP program on the Windows box yours or under your control? Or
are you writing something that does an SNMP GET to this windows box? If
it's your program, have a look at the 'interface' option that Stephen
mentioned. Otherwise it becomes a non-twisted issue around the interface
configuration on the Windows box. You want to be able to set the box up
so that it always sends packets out with a known source IP, or have the
receiving program identify responses in an IP address independant way.

-- 
Justin Warren <daedalus at eigenmagic.com>