[rhn-users] ip_forward problem

[Corné Beerse]

diego soares wrote:
> Hello to all.  
> I am with a well strange problem and I do not know
> more what to make.  
> 
> I have an ADSL sharing the Internet for the internal
> net.  The modem is in eth0 with IP 10.0.0.140 the net
> is in eth1 with IP 192.168.0.1 
> 
> Has squid making proxy/cache, everything functioning
> perfectly.  But at the active moment that I
> ip_forward(echo 1 >/proc/sys/net/ipv4/ip_forward)
> constraint everything!  
> ping for out is not, traceroute done of the proper
> server and of you scheme them of the net stop in the
> IP of modem(10.0.0.138) 
> 
> If I to disactivate 
> (echo 0 >/proc/sys/net/ipv4/ip_forward) 
> return everything to function Have only this rule in
> iptables 
> iptables -t nat -A POSTROUTING -s 0.0.0.0 -o eth0 -j
> SNAT --to 10.0.0.140
> 
> somebody can help me?

I think this is in the used IP range... Both the 10.x.y.z addresses and the 
192.168.a.b are so-called private ranges (there is an other one in the B-class, 
don't know it by head). By default, most routers are configured not to route 
these addresses, except when direct connected.

To solve this, you might need to configure hard-routes. Most easy: use the 
gateway on the remote network as gatway on the local network and define a static 
route to that remote gateway. There are many other ways to address this.

Best to check your provider for how to configure a router at your side. Good 
change that you get an other IP address on your internet-side. If you are not 
allowed to, then your provider is realy cheap on IP addresses, get an other 
provider.


CBee