[ubuntu] packet forwoading using IPtables

[turki_00]

Hi,

I have 2 Ubuntu boxes sitting in the same subnet; server 1 [130.15.6.68] and server 2 [130.15.6.69]

What I am trying to achieve here is the following:

 

server 1 act as a gateway or proxy to server 2, meaning that server 1 is exposed to the Internet and all traffic to server 2 should go though it (i hope!).

 

server 2 act as application server and I don't want a direct access to it from the internet. I want all the inbound traffic comes through server 1.

 

for testing purposes, i will limit the traffic to simple http or port 80

 

in server 1, i have done the following settings:

iptables -t nat -A PREROUTING -p tcp -i eth0 -d 130.15.6.68 --dport 80 -j DNAT --to 130.15.6.69:80

iptables -A FORWARD -p tcp -i eth0 -d 130.15.6.69 --dport 80 -j ACCEPT

 

Also,

In server 1, I've edited the value of net.ipv4.ip_forward to equal 1 (uncomment that line in /etc/sysctl.conf)

 

Currently, both server 1 and server 2 has its own apache2 servers with different index.html files.

 

the problem is, when i browse to server 1, I am still seeing its index page rather than being forwarded to the index page of server 2.

 

how can i achieve the traffic forowrding from server 1 to server 2 when my browser pointing to server 1?

 

Thank you in advance

[NixNerd]

Hello turki_00

 

Try following the instructions here:

 

Port forwarding for iptables (DMZ)

 

You'll need to specify eth0 - rather than eth1 (of course), you may note the --state NEW and --m state flags (see man iptables for more info), you may or may not need those - depending upon which version of iptables you're running.

 

Good luck and hope you manage to get it sorted out