Re: problems with eth0 set-up

["Donald R. Spoon" <dspoon@satx.rr.com>]

Rachel Andrew <lists@rachelandrew.co.uk> wrote:

> further to that last email, I just did:
>
> route
>
> and while localnet appears immediately, the default gateway takes about 5 
> minutes to appear. When it does appear it looks correct (as compared to my 
> other box with a similar configuration) however I still have no access into 
> or out of this box.
>
> Rachel
>
> --snip-- <


Rachel,

Most of the times I have seen this sort of behaviour, It has been due to 
an incorrect DNS lookup.  The DNS servers in /etc/resolv.conf don't have 
any idea about the IP number requested and "times-out".  Five minutes is 
a bit long for this process, however.

Another possiblility is that you have eht0 setup to use dhcp and it is 
trying to get an IP assignment from a dhcp server, and it the server) is 
NOT responding.  Once again the 5 minute delay is a "time-out" from the 
dhcp server...which also will try to set your DNS servers in 
/etc/resolv.conf depending on the dhcp client you are using.

You have not given us much info about your hardware setup, so it is hard 
to determine the EXACT cause.  If your ISDN router is also doing Network 
Address Translation (NAT), and is supposed to be a dhcp server, it 
"should" work if you have eth0 setup to use dhcp.  The main suspect here 
would be the DNS settings in /etc/resolve.conf.  On the other hand if 
your ISDN Router is expecting a "static" IP and eth0 is setup to use 
dhcp, then you probably should change it to use a "static" IP in 
/etc/network/interfaces.  Again, you will have to have some "good" DNS 
servers listed in /etc/resolv.conf.

If you have other machines on the network and can ping them by IP number 
(the gateway after it comes up in "route" is a good one to try) but not 
by name, then this is almost diagnostic of improper DNS servers.  If you 
cannot ping even the gateway, then something is wrong with the NIC 
setup.  I doesn't sound like this is the case here, though.

The results of "ifconfig", "route" and "lsmod" commands would be helpful 
in diagnosing the problem.  Also a copy of your /etc/network/interfaces 
file would be helpful.

Cheers,
-Don Spoon-