In rec.crafts.metalworking on Tue, 03 Jan 2006 10:51:28 GMT
Gunner wrote:

Well..with the kind help of you good folks..I managed to bumble my way
into getting this bitch online..but its still not right. If I closed
etho0, it will allow me to go on line. The moment I start it..it cuts off
the internet. This after inputting the proper dns numbers. Ive got some
clues where to start looking..but this is still a whole new ball game to
me.
Many thanks so far G

Well, if you are going via dialup, you aren't using eth0. You are
using an ethernet device called ppp0. (if you are using ADSL not
dial up then everything changes...)

So don't bother messing about with eth0, ignore it. Do everything you
were thinking of doing with eth0 but do it with ppp0 instead.

Which includes your firewall....

What's going on is that eth0 is waking up and going "OK, I have been
told to set a default route of x. So I will tell all packets that are
going to the internet to go through me."

So if you need eth0 for something else, like an internal network, find
out where eth0 is setting the default route and tell it to stop.

How to do that is distro dependent.

You can see if this is the problem by starting an xterm or rootshell
and
netstat -rn

You are looking for aline like
0.0.0.0 192.168.1.124 0.0.0.0 UG 0 0 0 eth1

The 4 zeroes on the left are the default route, they say "everything
that's not specifically mentioned elsewhere takes this route". So any
packet addressed to a host that isn't mentioned elsewhere in netstat
(meaning the whole internet) goes out that route.

You can see on mine there's eth1 on the right. If you have only eth0
and not ppp0 then eth0 has stolen the default and you have to tell it
not to.

If you have 2 such lines, one for ppp0 and one for eth0 then all the
packets are confused and don't know which one to use. So you have to
delete both and recreate one.

To save yourself that hassle, before you start ppp edit whatever it is
that starts eth0 and tell it not to set a default route. How you do
that is distro dependent, so unless you are using a redhat one I can't
help.

THen bring up ppp. Use netstat -rn to see if the default is going out
ppp0.

Next bring up eth0, and check that it isn't grabbing the default.

Zebee