Baslinux mailing list

[baslinux AT lists.ibiblio.org]

Message from Steven
===================
Christof wrote:
>
> May be my mistake was that I thought firewall is 
> something what only makes a working connection 
> more secure. 

You are correct, you do not need a firewall for
IP forwarding.  However, a firewall is necessary
for IP masquerading (routing a private network 
to the internet).  I assume you have a firewall
in your wireless router and it is already capable 
of routing local traffic to the internet.

> Now it seems to me that there will not be a 
> connection at all without the firewall. 

That is not correct.  You do not need a firewall
to route traffic from the client machine through
the GW machine to your wireless connection.

CLIENT           GW            WIRELESS ROUTER       
192.168.1.2------192.168.1.1
                 10.0.0.2--------10.0.0.x

> What I did:
> route add default gw 192.168.1.1 on client machine

This tells the client to route traffic for non-local 
addresses to the GW.  Specifically it sends packets
which do not have 192.168.1.x addresses to 192.168.1.1
The GW machine then decides what to do with the packet.

> The result: 
> both machines ping to each other

The 192.168.1.x network is good.

> GW machine is online 

The 10.0.0.x network is good and the GW machine
has a good default gateway to the internet.  Note:
the GW has its own default gateway to the internet
(I'm guessing it is 10.0.0.1).  Each machine has
its own default gateway, and they are different.

> client machine pings to 10.0.0.2

This is the same as pinging 192.168.1.1.  Both
of those addresses refer to the same machine.

> client machine does not ping to 10.0.0.138 and 
> has no connection to the internet

There are two possible reasons for this:
(1) the GW machine is not set for IP forwarding
(2) the wireless router does not know how to
    find the client machine

To fix (1) echo "1" > /proc/sys/net/ip_forward

To fix (2) tell the wireless router where 
to send traffic addressed to 192.168.1.2  
--------------------------------- 
route add 192.168.1.2 gw 10.0.0.2
---------------------------------
The question is:  are you able to edit the
routing table for the wireless router?

Cheers,
Steven