[oclug] Weird Network Error

[tommaxwell at home.com]

Hello,

I've got a really really weird problem with my NICs which I just can't 
figure out.

I have two Network cards, one being for the LAN the other being 
connected to the Cable Modem.

The Internal NIC is working fine I can ping the other computers on 
the network and they can communicate normally.

With the other NIC connected to the Internet it's a different story.
The NIC comes up fine with all it's IP details as per usual.
When I try to ping ANY IP address I don't see any ping replies, 
BUT when I am in another task window and run TCPDUMP on the 
Interface (while it is pinging) I can see the ping requests and the 
replies coming through fine.  There is also ARP and various other 
connections protocols.

Does anyone know what could be the result? It was working fine 
untill I shuffled around the NICs trying to get something else 
working.

Details:
NE2-PCI	ETH0 = Rogers IP
RTL8139	ETH1 = LOCAL LAN
Mandrake 7.0 running default kernel 2.2.17

The connection is up as I am writing this email through my 
Windows BOX with is directly connected to the Cable Modem.

The only thing I can figure out which MIGHT be the problem is the 
inherited Mandrake security policies.
I've turned off my firewall and ipchains states that all polcies are on 
ACCEPT.
Another error which has been sprouting up is in my 
/var/log/messages where it's stated that there is too much 
information on interrupt #### ( I can only assume that's my NICs 
address as it's the one causing me grief ).