Re: default route problem

[Dan Williams <dcbw redhat com>]

On Thu, 2008-11-13 at 13:47 +0000, Roy Marples wrote:
> Carlos Menezes wrote:
> > Dear all,
> > 
> > I don't know if problem I had is the same of yours:
> > When I try to connect to a WiFi network, I can't get a route to default
> > gateway. I discovered that default gateway is not in the same subnet I am;
> > for example, I got IP 10.2.203.20, netmask 255.255.255.0 and default gateway
> > was 10.2.0.1.
> > I solved by, manually, add a static route to 10.2.0.0/255.255.0.0 and a
> > route to default gateway.
> > I noticed that Windows machines do this automatically.
> > Could this detection (of local network and gateway in different subnets) be
> > done automatically? 
> 
> Sounds like it's serving out classless static routes which neither 
> dhclient or NM support. dhcpcd-4 does support them, and you can find a 
> NM-0.7 patch to allow this here [1].

There's also an open bug where NM should be adding a host route to the
gateway when it's out of the current subnet.  I have a patch for that,
but there were some netlink issues that prevented me from finishing it.

Routing is a bit tricky here because netlink thinks you cannot add the
route to the gateway out of the subnet until you add a default route via
0.0.0.0 first, then add the gateway host route, then replace the default
route with one via the gateway.

This isn't purely a netlink problem, since you can see the same issues
with /sbin/ip.

Dan