In our college they have set up a linux comp as a
gateway to access the internet. ( i am not sure if its
dial up or leased line)


I just wanted to know a few things about gateways:

(1) How to set a gateway on linux?

I have tried to add various routes to networks
using route add 0.0.0.0 0.0.0.0 and things like
that
Please tell me what route to add and what subnet to
add. I have successfully implemented squid proxy on
the linux but cant do so with a gateway..


What i want is that it should be a dial up gateway
with on demand dialling and disconnect on idle for
certain time.

and when even i ping the ip on local net it
shouldnt perform the DNS queries and dial to internet

The big problem i find with diald is that it many a
times performs unwanted queries to internet.
does ne one know any other s/w like diald.



Pls guide me ...


(2) What is a software router?

A few days back i read somewhere that linux
can be used as a software router. Does it mean that it
can work like cisco routers.
What i understand by routers is that a leased
line from exchange goes to leased line modem and then
cat5 cable from that goes to router.
So, can cat5 cable go directly to linux.

If yes how do I then do the routing settings.?