Re: default route problem

[Dan Williams <dcbw redhat com>]

On Sun, 2008-11-23 at 23:22 +0300, Kuznetsov Vjacheslav wrote:
> > On Mon, 2008-10-06 at 15:51 +0400, Vitja Makarov wrote:
> > > Hi, all!
> > > 
> > > Home ISP often use the following network configuration scheme:
> > > 
> > > - Lan IP address is assigned using DHCP
> > > - PPTP is used for internet connection
> > > 
> > > If pptp server is in your network, that should be ok to replace
> > > default route with ppp one,
> > > but when pptp server is routed via DHCP provided default route, you
> > > can't simply do it,
> > > you have first provide manually route for pptp server, then remove
> > default.
> > 
> > NM should be adding a specific route to the PPTP server via the
> > underlying device so that you can always get to the PPTP server while
> > connected. Then, it should be changing the default route to route
> > everything through the VPN _unless_ you've added your own specific
> > routes via the connection editor or the server has sent you specific
> > routes.
> > 
> > It seems it's not doing that here, correct?
> 
> I have a similar issue trying to use PPTP for internet connection. I
> have wrong default gateway device after the pptp connection established.
> Here is the routing table before pptp:
> 
> ---
> $ route -n
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags Metric Ref    Use
> Iface
> 10.73.197.0     0.0.0.0         255.255.255.0   U     0      0        0
> eth0
> 0.0.0.0         10.73.197.1     0.0.0.0         UG    0      0        0
> eth0
> 
> $ ip route show
> 10.73.197.0/24 dev eth0  proto kernel  scope link  src 10.73.197.6
> default via 10.73.197.1 dev eth0  proto static
> ---
> 
> and following I get after connection is done:
> 
> ---
> $ route -n
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags Metric Ref    Use
> Iface
> 0.0.0.0         10.73.197.1     255.255.255.255 UGH   0      0        0
> eth0
> 10.73.100.1     10.73.197.1     255.255.255.255 UGH   0      0        0
> eth0
> 10.73.197.0     0.0.0.0         255.255.255.0   U     0      0        0
> eth0
> 10.73.0.0       0.0.0.0         255.255.0.0     U     0      0        0
> eth0
> 0.0.0.0         10.73.100.1     0.0.0.0         UG    0      0        0
> eth0
> 
> $ ip route show
> 0.0.0.0 via 10.73.197.1 dev eth0  proto static
> 10.73.100.1 via 10.73.197.1 dev eth0  src 10.73.197.6
> 10.73.197.0/24 dev eth0  proto kernel  scope link  src 10.73.197.6
> 10.73.0.0/16 dev eth0  scope link
> default via 10.73.100.1 dev eth0
> ---
> 
> As you can see it does not use the ppp0 device. And I have to correct
> the default route to have the internet:

Have you defined any custom routes in the UI?  AFAIK pptp cannot return
custom routes from the VPN server, so that means you probably configured
custom routes.   These are pointless when the VPN is meant to be the
default route (since the traffic to that device would usually just be
routed over the VPN anyway when the kernel hits 0.0.0.0 in the routing
table).

Dan