Re: iptables

On 2011-06-22 Manu wrote:
> In my home network, I have a linux machine with debian6.
> My debian has to do dhcp server with isc-server.
> I have 2 network card, eth0 = public Ip (adsl modem)
> eth1 = lan.
> My dhcp server runs.
> But I can't connect to internet with pc's.
> Description :
> 
> network  : 10.20.30.0
> mask : 255.255.255.0
> Windows server: 10.20.30.2
> Linux server (Debian6) : 10.20.30.1 (DHCP a    nd gateway to wan)
> Accesspoint Wifi : 10.20.30.3
> NAS server : 10.20.30.4
> MAO PC: 10.20.30.5
> laptop : 10.20.30.6
> IP phone : 10.20.30.7, 10.20.30.8, 10.20.30.9
> I can connect to lan machines but not to wan.

Do the hosts in your LAN have a default gateway, i.e. does your DHCP
server pass out a router option with the leases? Check with "ipconfig"
on Windows or "route" on Linux hosts.

> cat /proc/sys/net/ipv4/ip_forward is 1
>  
> What are routes I have to create with route command ?

Normally you shouldn't have to create any for that kind of setup.

Please post the output of "iptables -nL" and "iptables -t nat -nL".

> How can I routed 80 port to 10.20.30.1  with iptables ?

That is called port-forwarding, not routing. It's done via DNAT. See [1]
for instance.

[1] http://www.debian-administration.org/articles/73

Regards
Ansgar Wiechers
-- 
"All vulnerabilities deserve a public fear period prior to patches
becoming available."
--Jason Coombs on Bugtraq