Two PPP connections to the same ISP with same remote gateway

[Tom Jobbins]

Thanks for replying, Daniel

>On Fri, 13 Jan 2006 08:07, Tom Jobbins wrote:
>  
>
>>This can be demonstrated from the command line with the following:
>>[root at magrathea:~]$ ifconfig tun0 1.2.3.5 1.2.3.250
>>[root at magrathea:~]$ ifconfig tun1 1.2.4.4 1.2.3.250
>>ifconfig: ioctl (SIOCAIFADDR): File exists
>>    
>>
>
>This is really odd, because I don't see this on my machines (as per our discussion on IRC which you mention below), I did..
>
>midget# uname -a
>FreeBSD midget.dons.net.au 5.4-STABLE FreeBSD 5.4-STABLE #4: Mon Aug  1 09:01:42 CST 2005    darius at midget.dons.net.au:/usr/src/sys/i386/compile/MIDGET  i386
>
>midget# cat /dev/tun &
>[1] 21524
>midget# cat /dev/tun &
>[2] 21525
>  
>
I've isolated the difference.   If I repeat exactly what you do - 
including the two cat /dev/tun commands - then it works for me too.   So 
long as the tun0 and tun1 interfaces are created with a cat /dev/tun &, 
I am able to give them matching remote gateway addresses.

However this is not the case when the interfaces are created any other 
way, i.e. via ppp.  Ditto ng0/ng1 created by mpd.

Also, if I then kill the cat /dev/tun commands, leaving tun0 and tun1 
existing, but unopened, I am then no longer able to set the matching 
gateway.   And if I don't kill the cat commands, ppp can't use those tun 
devices because another process has them open.

So it would appear this was just a dead end.  I don't know whats 
different about an interface created with the cat command - perhaps as 
it's not connected to a real network utility, the normal route checking 
does not apply?

If you - or anyone else - has any more ideas as to what I can try to 
make this work, I would be most grateful.  It's incredibly frustrating 
to be limited in this way, given that I'm almost certain that ipfilters 
source-based routing will get around any routing issues if I could only 
bring the interfaces up.


Thanks


Tom