Re: Can we make NM automatically handle the need for proxy arp?

["Darren Albers" <dalbers gmail com>]

On 8/27/06, Darren Albers <dalbers gmail com> wrote:
> On 8/27/06, Darren Albers <dalbers gmail com> wrote:
> > So I don't think this is a Network Manager issue but a Linux
> > networking issue, can you run ethereal and post the output from
> > windows and linux?
>
> Actually I don't even think this is a linux networking issue, in
> retrospect letting any device running proxy-arp route your traffic
> seems to be a VERY bad idea.  I suspect that the Linux networking
> stack is doing the smart thing in this case.  I wonder if you just
> remove the default gateway will Linux let any device that is arping
> that it knows the route to something take the traffic?
>
> If you boot into windows and run route print does it show some strange
> routes in it?

Ok I just confirmed that Windows is brain-dead in this regard, I
slapped up a Cisco 2600 I have sitting in my lab and enabled proxy-arp
on the directly connected interface and then setup a second interface
(So the router has someplace to send traffic to).  So on my windows
machine I have a default gateway set to another router but windows
ignored that and sent my traffic for the test network to the router.
This is brain-dead, if I specify that 0.0.0.0 0.0.0.0 needs to go to
1.1.1.1 then it should not let some device arbitrarily tell my system
that it has a better route to that network unless that is something I
/want/ it it do.

With my Linux laptop if I have a default route it ignores the router,
but when I remove the default route it adds the route to my system.

I personally think Linux is doing the right thing, imagine the havoc
if someone plugs in a device on a public wifi that arps that it knows
the way to 2.2.2.2 which also happens to be the IP that hotmail uses.
They then sit there and collect all the logins....