Iptables is a module that provides the Linux operating system functions of firewall, NAT and logging of data traveling over a computer network.

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IP forwarding on the same network

I have a raspberry pi that I have put wifi on. I am also using its ethernet connection to bring internet to my XBox 360. I want to bridge these connections AND keep them both on the same network. For ...
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166 views

Block brute-force on server with http auth behind cloudflare proxies

My server is behind Cloudflare proxies. I have configured simple http authentication to restrict access to some server resources. I'm trying to block brute-force attacks on http auth with fail2ban. ...
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126 views

IPTables masquerading stops working

In a classical SOHO setup I am running a Debian box as router/firewall. For an unknown time now I have an issue, where the MASQUERADING on the output connection (PPPoE) stops working for one of the ...
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163 views

Iptables: allow specific ips on specific port

I am trying to allow a few IPs on port 80 and disallow all other from access port 80. Can someone suggest the iptables rules needed for this to occur?
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How do I configure DD-WRT to forward IPSec traffic to an internal server to support a road warrior configuration?

I use dd-wrt as my home router setup and that's been working fine. Now I wanted to figure out a way to be able to use my iPad to set up a IPSec tunnel to my home network while I'm on the road. PPTP ...
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Using iptables SNAT based on source interface and ip address

I would like to change source ip address according to ip address and interface it came in. Let's consider following example: ----------------------------- | | | ...
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539 views

Sharing transparently proxied Internet connection with PS3

I am trying to play a Japanese karaoke game on a PS3 but the latency is just horrendous and downloading songs takes forever. One recommendation I got was to turn my laptop into a SOCKS proxy by ...
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1answer
705 views

DNS resolving broken after installation of bind due to iptables

I successfully configured my web server (Apache, PHP etc.) and blocked the ports I don't need using iptables, which was working perfectly fine. Today, I installed BIND and configured it, which also ...
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66 views

Accessing ports remotely

I have a fedora server on a local network which I can access through VNC. I am trying to install a JIRA plugin called Activity timeline, these are both built using Java. When I log into VNC and ...
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434 views

set https proxy with squid and iptables

have a Linux as router, eth0 (192.168.0.60) connect to LAN, eth1 (10.100.33.239) connect to Internet. squid works well, I can set 10.100.33.239:3128 or 192.168.0.60:3128 as proxy in web browser and ...
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282 views

Port 6667 can't be reached outside of localhost

I've got IRCD-Hybrid installed with the following listen config: /* listen {}: contain information about the ports ircd listens on (OLD P:) */ listen { /* port: the specific port to listen ...
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2answers
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How to use iptables to connect proxy server

In my company, all http and https must connect to a proxy server, which means we must set proxy in our web browser. Our department has an internal network (192.168.0.xxx). I use a Linux server as ...
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236 views

Open up firewall automatically to anybody who has successfully connected via SSH

I have a server which runs a few services. However, for security reasons, I configured the server so that nothing, except for SSH, is accessible from outside. What I'd like to do instead, though, is ...
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1answer
2k views

How to configure a firewall on Centos using Vagrant and Chef

I've created a server box using Vagrant and Chef and everything is up and running correctly. However, when the box is installed from scratch the default iptables rules are in place and so I need to ...
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1answer
383 views

Filter multicast from WAN to specified vlan

I'm using ebtables to filter multicast IPTV from my Wireless and Wired Lan. Right now its configured like this: Router ( DD WRT ) VLAN1 (PC Network) VLAN2 (IPTV) I am using this command: insmod ...
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330 views

tc/netem and iptables: Delay traffic only from specified ip and port

I have a Ubuntu Router with 2 network interfaces. eth0 is the private network and eth1 is the internet. What I want is the following: All packages (mostly udp) comming from a specified private ip ...
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684 views

iptables: How to redirect port in Red Hat Linux (RHEL)?

I'd like to forward port 80 to 8080. So I tried to edit /etc/syscongfig/iptables: -A PREROUTING -t nat -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 8080 But got: # service iptables restart ...
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685 views

iptables routing marked packets from router to PC and routing them back to router

I'm trying to do deep packet inspection on HTTP packets. The purpose of this is to collect HTTP payload data and then create some proxy/cache-independent reports. Following this, the idea is to ...
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123 views

How to unblock jabber on TI ADSL router with iptables

I have old but reliable Texas Instruments ADSL router. Board AR7RD; BUILD=061005; VERSION=3.7.1 If that matters... One thing that bothers me is that it somehow blocking my jabber (Pidgin ...
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1answer
370 views

IPTables - unknown error 4294967295

I've moved an old Slackware 11 installation from a physical PC to a virtualized in ESXi. Everything seems to work fine except for one rule in iptables, namely the row: iptables -t filter -I INPUT -m ...
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1answer
1k views

Access Apache server running in Fedora guest VirtualBox from host

I have trouble accessing Apache server from host. I’ve Fedora 15 VM VirtualBox installed on Windows 7. Within this VM I have Apache server running and working fine within the guest. Not sure what ...
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1answer
170 views

amule, Fedora 14, iptables

I need to set iptables rules for aMule, but I am not sure which one are the right ones. Googling around, I have seen something like: iptables -I INPUT -p tcp --dport 4662 -j ACCEPT iptables -I ...
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429 views

How to “shut off” all networking on Linux from bash?

I'd like to write a bash/shell script that "turns off" the machine's ability to communicate over it's network card, effectively shutting down all networking. From the command line: # To turn all ...
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355 views

how to telnet redirect ip and host using iptables

I try to telnet from PC 3 To PC 1 and it's redirect to PC 2 PC 1 : 192.168.0.1 PC 2 : 192.168.0.2 PC 3 : 192.168.0.3 i have command like this in PC 1: iptables -t nat -A PREROUTING -p tcp -d ...
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187 views

What is command to look list of redirect rules, iptables

im using command like this : iptables -t nat -A PREROUTING -p tcp -d 192.168.1.118 --dport 4080 -j DNAT --to-destination 192.168.1.118:4088 My question what is command to look all rules in the ...
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706 views

How to route specific traffic through OpenVPN?

I'm running a server at home with rtorrent and apache2. I would like to route my rtorrent traffic via OpenVPN and since im kinda new to OpenVPN and iptables i would like to have a user friendly guide. ...
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1k views

iptables port based routing

I've been Googling this for days with no success. I connect to a VPN from my server from time to time and I'm trying to configure my Debian server to only use port 80 and 443 through the VPN and all ...
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61 views

why does this iptable rule work at a specific position in the chain

I'm running OpenWrt on my router, which allows me to run applications such as apache and emule. I installed emule but I keep getting lowid, indicating that my port is misconfigured. I was able to ...
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No output returned when curl ing any URL in Red Hat 6 but the same url works in lynx browser

I am trying to install some packages in Python using easy install. But i get a 'Download Error' for any package i try to install. So i tried to test if internet is accessible at all from the machine ...
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2answers
3k views

How to route specific traffic through OpenVPN?

I'm running a server at home with rtorrent and apache2. I would like to route my rtorrent traffic via OpenVPN and since im kinda new to OpenVPN and iptables i would like to have a user friendly guide. ...
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OSX: Mimic Ubuntu IP Masquerading via iptables with ipfw

Good day, I am attempting to replicate a setup I have between a router and an Ubuntu PC, and have the same setup working on my MacBook (10.6, Snow Leopard). First, I have a router that has a USB ...
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132 views

How to resolve conflict in iptable rules

In Ubuntu 12.04 and above there are no iptable rules defined by default. I added the following rule and it works fine:(Update) iptables -A INPUT -p tcp -j QUEUE -m string --string xyz --algo bm ...
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120 views

1:1 NAT IP address using iptables

Suppose I have 2 internal networks: 1.1.1.0/24 and 1.1.2.0/24 I would like to NAT a specific IP address from one network to the other, in which the new address would be obtained via DHCP. For ...
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417 views

MIxing RFC1918 NATed and public IP addresses using IPTABLES

I wish to host a SIP server and DNS at the end of an ADSL2 connection. My current network sits behind an iptables firewall which runs on a Linux box with two Ethernet interfaces, the WAN interface ...
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IPTables Allowing Access without Rules

I'm sure this is mostly my misunderstanding of how iptables works, but I've set up some rules... -A INPUT -p tcp --dport 22 -m state --state NEW,ESTABLISHED -j ACCEPT -A OUTPUT -p tcp --sport 22 -m ...
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1answer
704 views

How to configure port forwarding for an IP camera

I need to configure port forwarding for my IP camera so that I can access it from internet. UPNP is not supported on my gateway. My network configuration is the following: Gateway (Ubuntu Server 12) ...
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2answers
779 views

How to route the incoming connections through a specific interface?

I have multiple ethernet cards with two different set of networks configured on them. The output of route -n is given here:: Kernel IP routing table Destination Gateway Genmask ...
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1answer
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Load balancing with multiple gateways

I have to different ISPs, each on each own network. The main connects via ethernet and the secondary via wifi. The two networks have no relation at all. I just connect to them simultaneously. The ...
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2answers
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need to route the traffic through a specific network card

I have two network cards and they both have a different network. I need the outgoing connections to go only through a specific network card. Any help ? Update: I ran a route -n command and got this ...
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1answer
140 views

Why does Firefox need a loopback connection?

I was playing around with firewalls and iptables. When I blocked any traffic except HTTP and DNS I was able to establish a connection to google.com via wget google.com. But I wasn't able to open ...
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557 views

iptables block everything except http

I'm trying to configure my iptables to block any network traffic except HTTP: iptables -P INPUT DROP #set policy of INPUT to DROP iptables -P OUTPUT DROP #set policy of OUTPUT to DROP iptables -A ...
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Centos iptables blocks after reboot

I have a Centos5 installation with kvm on my server. I am using nat portforwarding to ssh my virtual machines. I have several iptables rules and saved then in /etc/sysconfig/iptables. After reboot, I ...
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228 views

IP forwarding with iptables

Suppose there are hosts A and B. A is allowed SSH access to B based on its IP address. Consider now another host C. C does not have access to B, but if we could route its traffic through A, then C ...
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2answers
7k views

CentOS 6 - iptables preventing web access via port 80

I'm setting up a new web server with CentOS 6.2 and am not able to connect via the web. Everything looks set up correctly in httpd.conf and Apache is running, so I'm assuming it's an iptables issue. ...
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1answer
204 views

dd-wrt: Keep source ip after port forward

I just started using dd-wrt on my wndr3700, but now all my incomming connections to a server inside the network gets the same source ip as the router. How can I change this back so I get the real ...
2
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1answer
241 views

Different routing rules for a particular user using firewall mark and ip rule

Running Ubuntu 12.10 on amd64. I'm trying to set up different routing rules for a particular user. I understand that the right way to do this is to create a firewall rule that marks the packets for ...
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293 views

IP tables gateway

I am trying to make an iptables gateway. I ordered 3 dedicated server from my hosting company all with dual nics. One server has been given all the ip addresses and is connected directly to the ...
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1answer
806 views

Pinging an external server through OpenVPN tunnel doesn’t work

I have an OpenVPN server and a client, and I want to use this tunnel to access not only 10.0.8.0/24 but the whole internet. So far, pinging the server from the client through the tun0 interface works, ...
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1answer
162 views

CSF Unresolved issue

I began receiving service failures for CSF/LFD once the limit was reached in iptables preventing the service from working properly. I flushed all iptables rules, and redid by rules using CIDR rather ...
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iCloud stuff stops working while connected to OpenVPN

I have a fairly simple OpenVPN setup on an OpenVZ VPS with Ubuntu 11.10. Client is the Viscosity client on Mac OS X 10.8.2, and after some testing, we can rule out the client as being part of the ...