[H-GEN] dialup under linux

[Tony Nugent]

[ Humbug *General* list - semi-serious discussions about Humbug and     ]
[ Unix-related topics. Posts from non-subscribed addresses will vanish. ]

On Wed Mar 12 2003 at 09:17, Shaun Nykvist wrote:

> It has been a while since I have used dialup under linux and I know that I
> am missing something here.  I have helped a friend set up a connection to
> the internet on his debian linux laptop.  He uses the laptop at work on the
> local area network (static ip) and accesses the internet there with no
> problem.  At home he also wants to access the internet.  His current setup
> dials the number and negotiates a connection.  plog shows that it has
> connected and the ip addreses etc.,

Ok so far...

> however he cannot access the
> internet.  I think the issue lies with the fact that he has already got a
> default gateway set from his static settings.  can someone offer some
> guidance on this issue

Bingo, that is exactly the reason... pppd will not add a default
route via a new connection if one already exists.  Check the logs
(with "pppd debug") and you'll notice messages to that effect.  The
reason for this is because in many cases if a default route already
exists, then the assumption is that the box is to act as a gateway
for the remote peer.

You'll need to add a "defaultroute" parameter to the ppp config
(options or peers) file in order to force it to happen.

If doing that is problematic, then you have another recourse...
after the networking on the ppp link comes up, pppd runs a script
called /etc/ppp/ip-up which is given a number of parameters
pertaining to the connection (see man pppd).  You can add to that
script so that it uses these parameters to run /sbin/ip or
/sbin/route to reset a default route to the ip address of the remote
peer on the ppp interface.  And in /etc/ppp/ip-down you can also add
similar things to restore it to its previous settings.

> Thanks
> Shaun

Cheers
Tony

--
* This is list (humbug) general handled by majordomo at lists.humbug.org.au .
* Postings to this list are only accepted from subscribed addresses of
* lists 'general' or 'general-post'.  See http://www.humbug.org.au/