[Techtalk] network trouble

[Dennis Wheeler]

I'm stumped.

I have a linux gateway for a windows lan but I can't communicate  with the
linux box on it's exteranl interface

dsl network:
  x.x.x.136   netmask 255.255.255.248   gateway (dsl router) x.x.x.142

linux eth0  x.x.x.138
      eth1  192.168.0.2

windows 192.168.0.15 (or any other os machine for that matter)

from my windows machine I can ping the gateway 142 and any other external
server (google, etc)

from the linux gateway I can ping any server on the interanl interface
192.168.0.x, but not the dsl gateway x.x.x.142 nor any other external
address

as far as I can tell, I've temporarily turned off all firewalling

I can bring the interface down and up again

I don't know what the problem is, and I don't know where to look next.

Any pointers would be appreciated.

-- Dennis