Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

I am using PRIVOXY as a transparent proxy on a Fedora Core 11 box. The machine has one interface (eth0) and here is the configuration of the network:

10.0.1.1 - router.foobar.com (connected to ISP) 10.0.1.2 - proxy.foobar.com (proxy) 10.0.1.199 - DHCP server

I have set the default gateway option in DHCP to be 10.0.1.2 so ALL TRAFFIC destined for 0.0.0.0/0 SHOULD pass through it (and 10.0.1.1) on it's way out to the internet.

Here is my problem.... How do I ensure that traffic that is coming in/out of the network follows the correct path and does not create weird routing issues. I see some delays when using the proxy, but when I do a "straight shot" out to the net by changing my default gateway, I see no delays.

Here is my current iptables conf file:

# Generated by iptables-save v1.4.3.1 on Fri Jul 30 17:02:45 2010
*nat
:PREROUTING ACCEPT [1565:151406]
:POSTROUTING ACCEPT [1467:94514]
:OUTPUT ACCEPT [768:48101]
-A PREROUTING -i eth0 -p tcp -m tcp --dport 80 -j REDIRECT --to-ports 8080 
 COMMIT
# Completed on Fri Jul 30 17:02:45 2010
# Generated by iptables-save v1.4.3.1 on Fri Jul 30 17:02:45 2010
*filter
:INPUT ACCEPT [12764:10577001]
:FORWARD ACCEPT [3755:525228]
:OUTPUT ACCEPT [14364:12738086]
-A INPUT -i eth0 -p tcp -m tcp --dport 8080 -j ACCEPT 
COMMIT

I know that I am missing something, I just don't know what... I think that I need to do something like:

-A POSTROUTING -i eth0 -o eth0 -d 10.0.1.0/24 --SNAT 10.0.1.1
share|improve this question
add comment

1 Answer

up vote 0 down vote accepted

The default gateway on 10.0.0.2 has to be 10.0.0.1, /proc/sys/net/ipv4/ip_forward must be 1 and not 0.

Also remember that privoxy is a proxy and it can add some delay.

share|improve this answer
    
My default gw is set to be 10.0.1.1 on the proxy box: 10.0.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth1 0.0.0.0 10.0.1.1 0.0.0.0 UG 0 0 0 eth0 And IP forwarding is turned on: root@proxy ~]# cat /proc/sys/net/ipv4/ip_forward 1 I know that pulling through a proxy is going to add delay, but it seems to be "unnaturally" slow –  QWade Aug 2 '10 at 16:11
    
Isn't privoxy doing something weird, like running tor or something? –  coredump Aug 2 '10 at 18:11
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.