Networking :: IPTables - Redirecting Web Traffic To Single Transparent Proxy Server
Mar 25, 2010
I am new to iptables. We have two Squid proxy servers running in "non-transparent mode" (172.16.0.1 and 172.16.0.2). Currently users have to configure the proxy server they want to use by configuring them in their browsers. Recently I saw an example for redirecting web traffic to a single transparent proxy server.
Can anyone modify this rule to accommodate my current setup of two proxy servers running in non-transparent mode. i.e Redirect web traffic to the 172.16.0.1-172.16.0.2 ip range.
I am trying to set up my squid3 proxy as a transparent proxy - right now, I have to manually configure browsers to access via proxy. I understand that I have to put some rules into Iptables and also some further directives in the squid.conf.
I have a couple of specific questions. The proxy server is running on a Ubuntu 10.04 workstation and this machine also acts as a dhcp server for the network. I have just one subnet , namely 192.168.0.1-254 There is only 1 network card. Is it much easier to put in a second network card or is it just as easy to configure the existing lan card as a dual IP?
Is it necessary to configure these 2 IP's ( whether they are via 2 lan cards or dual IP on single card ) to be on different subnets. i.e ETH0 192.168.0.1 and ETH1 192.168.1.1 or is ok to have something like ETH0 192.168.0.1 and ETH1 192.168.0.254 ( where ETH0 is the one facing the LAN and ETH1 points to the modem router / switch i.e The Internet ) Where specifically do I save the Iptables rule configuration file and what must I call it ?
trying to configure a transparent proxy with squid (and filter content with dansguardian) in Debian/Ubuntu. If i configure firefox to use it, it runs ok. I had seen a lot of iptables rules to use fowarding proxy to a lan, but i would like to use squid and dansguardin in a single pc that run them and filter web content.
I have big problem with correct settings of iptables as a router. My network topology (UTM Hardware router) 192.168.1.1--->eth0 192.168.1.2(centos with apache ftp and transparent squid 8080)--->eth1 192.168.0.1(LAN with dhcp)
eth0=WAN 192.168.1.2 eth1=LAN 192.168.0.1
I have problem with hanging connections through squid which are very slow or connection failed. Sometimes i received DNS timeout error from squid stable 2.6 21
what I am trying to do is use an external transparent proxy for only one of the hosts on my internal network. For example, for an internal host of 192.168.1.8, I want to send all internet requests for ANY port to a proxy server out in the internet at 238.34.232.7 / port: 8080. All other hosts would use the internet without using any proxy server. Is IPTables the way to set this up or is there an easier option?
I need to set up an ip table and a transparent squid proxy as followed: I have 3 machine: Machine 1 works as a squid proxy. It has 2 interface eth1 and eth2.
eth1: 192.168.99.2 (Connect to eth1 of machine 2) eth2: 192.168.98.2 (Connect to eth1 of machine 3)
machine 2 works as a webserver eth1: 192.168.99.4 machine 3 works as a web client. eth1: 192.168.98.4
my responsibility is to send all tcp traffic from machine 3 at port 80 to my squid proxy. In order to fulfill the tasks, I have edited the squid.conf as followed: Code: http_access allow localnet http_access allow localhost and in machine 1, I tried 2 ip tables command: Code: iptables -t nat -A PREROUTING -i eth2 -p tcp --dport 80 -j DNAT --to 192.168.99.2:80 iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 80 -j REDIRECT --to-port 80 I don't know if it is right or wrong.
I have searched for this quite a bit but my lack of knowledge of IPTables makes me doubt whether I have found a solution or not. I have very light experience with IPTables as well.So I thought I'd ask here.Basically, what I am trying to do is use an external transparent proxy for only one of the hosts on my internal network. For example, for an internal host of 192.168.1.8, I want to send all internet requests for ANY port to a proxy server out in the internet at 238.34.232.7 / port: 8080. All other hosts would use the internet without using any proxy server.
I setup squid with transparent proxy and its working, however, when I reboot the server, the proxy server doesnt work unless I run the following.
Code: # squid server IP SQUID_SERVER="192.168.1.1" # Interface connected to Internet INTERNET="eth0" # Interface connected to LAN LAN_IN="eth1" # Squid port SQUID_PORT="3128" [Code]...
I would like to redirect traffic coming from a machine A through a SOCKS proxy (setted on machine B)Machine B run "ssh -D 4242". So that create a SOCKS proxy on machine B.Machine A would like to connect on the internet, but the only way is to use machine B SOCKS proxy. The problem is machine A don't know how to use SOCKS Proxy. (Actually, i can just set ip, netmask and gateway on machine A).So, I would like to set up something on machine B that will redirect all traffic coming from machine A throught the SOCKS proxy.
I'm new to linux, but enjoy using it very much, especially without a GUI, console is fun! I need to set up port forwarding. We have 3 servers, 1x running Ubuntu server 8.04 (used as transparent proxy), 1x server 2003, 1x windows xp.
The linux box has the following ips: eth0 (internal) 192.168.1.5 eth1 (external) 192.168.0.7
Windows server 2003: 192.168.1.6
Windows XP: 192.168.1.9
Router: 192.168.0.1
The router automatically forwards specific ports to 196.168.0.7 (Linux eth0). From there I want to forward port 8585 to 192.168.1.6 and 3000 to 192.168.1.9. Is there a way that I can do this using iptables?
The commands that I think I'm gonna use look like this: iptables -A FORWARD -s 192.168.0.0/24 -p tcp --dport 8585 -d 192.168.1.6 -j ACCEPT iptables -A FORWARD -s 192.168.0.0/24 -p tcp --dport 3000 -d 192.168.1.9 -j ACCEPT
Would this be a correct way of doing it? My biggest problem is that I can't test it without going live, and if I go live and something doesn't work, the entire building will be left without internet, people will hate me. Also, The proxy captures all data on port 80 and forwards it to 3128 so that the proxy can monitor the usage, and a few systems runs fine with it, others however can ping websites, and internet explorer says "website found, waiting for reply" but the webpages cannot be displayed.
I got it set up in the NetworkManager applet (imported the client.ovpn), but when I connect it sends ALL my traffic through the VPN. I would prefer all accesses to the internet go over my normal default gateway, rather then all the way through to the VPN's default gateway.When I connect through the command line:
Code: openvpn --config client.ovpn I don't have this problem, and accesses to the internet still go over my default gateway on
I'd like to use ssh as a proxy/socks server and redirect all connections through this proxy. It would look like : ssh -D 123 -N host iptables ... I've never used iptables before and I did not manage to find any useful for this particular case solutions on the internet. So, what's the good way to do that ?
i've got a software that uses a specific tcp port e.g 11111. i want to redirect all the traffic from 11111 to squid port 3128. i'm using the following commands to redirecting:
my ubuntu server has two interfaces. eth0 is for local network (dhcp assigns ips) and eth1 is for internet. my ubuntu server acts as a gateway and as an authentication server for users.
at squid also i have the following configuration regarding my port:
acl myport port 11111 http_access allow CONNECT myport. my squid installation is not transparent as users need to authenticate in order to access the web.
my application is a windows application and of course is not working. i examined the packets with wireshark and i noticed that when the program tries to access the internet, squid replies with err_invalid_request (the packet contains that data). the program is trying to send some plain text via port 11111 and as far as i can image, somehow squid declines the data. i cant get rid off squid as i want to pass the traffic from squid. what is the problem?
I'm trying to setup a Centos 5.6 Squid Proxy Server with Content Filtering & Antivirus Scanning Incoming HTTP Traffic from the Internet
I then proceeded to setup an configure the Proxy Server, i was able to test and confirm that Squid and Dansguardian Content Filter is working, however i dont know if Clamav is scanning HTTP traffic before it hits the client/server. Is there a way i can check if the Antivirus scanning is working.. is there some log file or real world test i can i can do to confirm that Clamav is scanning incoming traffic or even blocking potential viruses ??
Anyone who has squid proxy server with Clamav configured and its working can share there settings/setup with me and how they tested it ??
I've been trying to redirect all outgoing packets (destined for a specified ip address) from my slack box back to itself. I thought this could be done with iptables, but if I fire up wireshark I can clearly see that the packets are getting out to the real server and I'm getting responses from it.
So here's what I tried:
All looks good and fine, and then I even try to visit 194.28.157.42 with firefox (by the way I am running a webserver, that is set to show a page when you visit 127.0.0.1) and I get an error page that reads: 502 Bad Gateway.
I ignored this message to see what the program I'm trying to interrupt does, and when I start wireshark and then start the program that is using that website, I can clearly see that the packets make it to the real 194.28.157.42 and get back responses.
I'm using Fedora Core5.0 I have using Iptables for forward port 80 to port 3128(Squid) in the same of server.I need to forward using Iptables to use the other proxy server because this server i am use for vpn and mail tranfer.What a Commnand for i use?ase 1. Server 1 >Ip 192.168.0.4 SQUID WITH PORT(3128)2. Server 2 IP 192.168.0.254 PF SENSE (3128) I will use server 2 for using internet connect only.
I had been running my SMTP server with WINE, as the SMTP server software is a Windows-based program (MERCURY), but I cracked the shits with WINE and removed it. Now I am running my SMTP server in a Windows virtual machine.This virtual machine has a different IP address from my host machine, so what I need is for my computer (the host) to redirect incoming traffic on port 25 to the virtual machine at 192.168.56.101 on port 2525.Can someone please help me with it? I think its done with iptables.
At the moment I have a proxy and all the users have to configure it in the browser to access internet. I want to make the users able to browse even without configuring the proxy in the browser. but eventually it should be received in the proxy rather than giving an error to the user. I heard with transparent proxy I can redirect all the traffic from a particular network, to a particular host( ie my existing proxy).
I tried this using firewall rules. But then the existing proxy doesn't understand the protocol of the requests. I heard that it should be in the kind of proxy protocol.
fedora (iptables) eth0 -private :192.168.1.1 eth1 -public : 186.117.50.6 squid proxy 192.168.1.10:3128 my clients range 192.168.2.0/24
how can i make my clients to browse internet only from proxy server my network is NAT 'ed. Please specify a iptable rule to allow internet access for my clients to browse ONLY if they come through proxy server.
I have installed and tried both squid version as transparent proxy but they just don't work.
I have eth0 which is where my internet comes in and eth1 which is my local network 192.168.1.0/255.255.255.0.
My default firewall policy is to drop input output and forward, i have already set my firewall to accept and workout the squid and it is working.
Here is the relevant rules i have on my firewall:
Code:
Here is the sample conf i am using for squid:
Code:
Always_direct allow all When using version 2.7.x i was able to make it transparent when i used the below rules:
Code:
I readed the Docs on the squid page but the above rules can't be reproduced to 3.1 and i don't wish to use such rules to make it transparent or hidden so i want some help to figure out why it inst transparent.
I am using Fedora 9, I have compile the squid with source code, i also deleted the old RPM of squid. i then edited the squid.conf in /usr/local/squid/etc and set http_port 3128 transparent and allowed in my acl to my local network but the transparent proxy is not working. if i remove transparent proxy then squid works fine. when i try to make it transparent the squid access.log file does not show any request coming to it (no activity). i have also forwarded all the incoming traffic to squid port 3128. Can anybody tell me why my transparent proxy is not functional.
I can very well configure squid transparent proxy on gateway server.But i want the squid transparent proxy on non-gateway system as i already have hardware firewall installed.i.e i want to redirect all the traffic coming through my gateway (hardware firewall) 192.168.200.1 to my squid server 192.168.200.3 on port 3128.How it is possible? Without transparent proxy by directly giving proxy ip in browser i can access internet but how to do it in transparent mode?
I want to make a transparent squid proxy server in centos. The squid proxy version is 2.6 stable. I made a normal squid server but want to make it transparent so that users do not need to enter the proxy settings in web browser. Even i searched about this on google but not getting it properly.I have two lan cards on centos system. ETH1 used for LAN and ETH2 used for WAN. And in this squid.conf i written "http_port 172.16.31.1:3128 transparent" and i also added a rule in iptables which is "iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 80 -j REDIRECT --to-port 3128" but still i have to enter proxy settings at client's web browser to use internet
I have a problem in Eclipse for accessing update sites (for plugins). I am behind a NTLM proxy. Strangely, this proxy asks for a password while in Linux but not when in Windows� To get around this annoying password issue, I already setup a working cntlmd proxy. I can use this proxy for mounting a remote DavFS2 share, for example. But the issue I have with Eclipse seems to involve proxy configuration. So I decided a transparent proxy could solve this issue. I installed tinyproxy on top of cntlmd, and added the following rule to the firewall:
Now, I can configure Firefox for direct access to the Internet, and display a web site only if I give this web site's IP instead of its name! I surmise that it's because when configured for direct access, Firefox performs DNS lookups using the local (intranet) DNS, instead of squeezing its lookups through the proxy and accessing a broader DNS (I wonder which). How can I make all DNS lookups go transparently through the transparent proxy?
I am playing around with transparent proxies, unfortunately I do not have two machines to test it out with. The current way I am doing things is the program makes a request to a computer on port 80, I use
Code:
iptables -t nat -A OUTPUT -p tcp --destination-port 80 -j REDIRECT --to-port 1234 to redirect to my proxy that is listening on port 1234. The proxy will send out a request to port 81 (as all outbound port 80 are being fed back in to the proxy and if it sent out to port 80 it would just be a infinite loop) so I want to do something like
Code:
iptables -t nat -A OUTPUT -p tcp --destination-port 81 -j DNAT --to-destination xxxx:80 The problem lies with the xxxx part. How do I change the destination port without changing changing the destination ip?
I'm trying to setup a linux box with 3 NICs (2 WAN links and 1 LAN). All http traffic (port 80) should go to WAN 1 via squid proxy and the rest to WAN 2. I already setup MASQUERADING in iptables and I already configured port 80 to redirect to port 3128 for squid. My default gateway is WAN 2. But the problem is squid uses the default gateway - WAN2. setting up the iptables / routing for squid to use WAN 1?
can anyone give me the solution how to configure dansguardian on squid transparent proxy.i m using linux - slackware squid - squid-2.6-stable18 dansguardian - 2.10.1.1
