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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In Linux can I direct all traffic from a specific ip address or mac address to file

In Linux can I direct all traffic from a specific ip address or mac address to file. I am look of a way to take all traffic from a specific ip address or mac address and put it into a file. Does ...
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How can I check if an iptables rule already exists?

I need to add a rule to iptables to block connections to a tcp port from the Internet. Since my script may be called multiple times and there is not a script to delete the rule, I want to check if ...
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Blocking Skype using snort and iptables

I am trying to block Skype using snort and iptables. I read a lot of papers and blocked the port, keywords and patterns which Skype uses. But it is still not blocked. My question is: if Skype uses ...
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How to block sites with iptables

I would like to block sites using iptables. How do I go about this, and how do I ensure that the iptables rules are saved?
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1answer
395 views

How can a PPTD VPN route traffic to other servers on network?

I a have a number of servers which expose various public services to the web. These are behind a server which is acting as a firewall using IPTables and forwards traffic to and from the servers. All ...
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Setup routing and iptables for new VPN connection to redirect **only** ports 80 and 443

I have a new VPN connection (using openvpn) to allow me to route around some ISP restrictions. Whilst it is working fine, it is taking all the traffic over the vpn. This is causing me issues for ...
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827 views

Firestarter device not ready when booting Ubuntu

I am trying to get firestarter running on Ubuntu 11.10 and I am getting an error: Failed to start Firewall The device eth1 is not ready. Please check your network device settings and make sure ...
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1answer
3k views

Ubuntu 11.10 firewall/gateway - no client internet access

I have read many other posts but cannot figure this out. eth0 is my external connected to a Comcast modem. The server has internet access with no issues. eth1 is internal and running DHCP for the ...
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How to use iptables to forward all data from an IP to a Virtual Machine

OK, in an attempt to get some response, a TL;DR version. I know that the following command: iptables -A PREROUTING -t nat -i eth0 --dport 80 --source 1.1.1.1 -j REDIRECT --to-port 8080 ... will ...
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1answer
341 views

iptables Settings as WAN Input for Router

I have an eee running ArchLinux with wireless access to the Internet. I want to use it as the WAN input for an Asus RT-G32 router into which it is hardwired. The router in turn is hooked up to a ...
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will the left|rightfirewall option of StrongSwan open UDP 500/4500 and protocol number 50 on iptable?

I know the StrongSwan use UDP 500 and 4500 for IKE traffic and IP protocal number 50 for ESP packages. I am not sure the usage of left|rightfirewall ...
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233 views

conectivity problem

I have 2 PCs (anuin and hed), both running Linux that are connected via ethernet (192.168.1.1 and 192.168.1.3). Both PCs can ping each other. anuin is connected to the internet via an USB-stick ...
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Chaining subnet fails

Is it possible to do the following: Machine1 Kubuntu 8.04 desktop wired internet Cable modem Machine2 eepc701 Xubuntu 1O.04 wired machine1 cross ethernet cable Machine3 nokia n900 wireless to ...
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1answer
3k views

Remove port aliases in iptables

How can I make iptables show me port numbers instead of aliases for well known port numbers (eg. http for 80, https for 443 etc.). Is there a way to make it show just port numbers at all times?
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1answer
772 views

iptables + vpnc + Cisco IP Phone 7941

I have a Linux gateway with kernel 2.6.39 connected to a Cisco ASA 5500 with vpnc. I'm using iptables with masquerading and forwarding to give the LAN access to the tun0 device connected to the VPN. ...
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1answer
431 views

Why small TCP connections succeeds, but big ones fails?

Sometimes from Linux system I see the following weird behaviour: I able to ping things and sometimes use some services, but networking is very bad. For example, now I routed connection through my ...
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How can I restrict my Virtual Machine using an iptables rule?

I am using CentOS Linux and am planning to setup a rule on my VM's iptable. I want to restrict all outgoing and incoming packets to the VM for a temporary period and allow only the DHCP packet to ...
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1answer
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How do I block all ports except 22 and 80 in Fedora's iptables? [duplicate]

I am trying to only allow port 22 TCP/UDP and port 80 TCP/UDP from anywhere using Fedora 15 iptables, and all the rest will be never accessible nor scannable from a public network. But it never ...
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iptables ACCEPT policy

In Redhat EL 6, iptables INPUT policy is ACCEPT but INPUT chain has REJECT entry in the end. /etc/syconfig/iptables is as below: *filter :INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [0:0] ...
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1answer
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DD-WRT Setting Up Guest Network

I have a router on which I installed DD-WRT firmware. I am trying to set up a virtual interface to use as a guest network. The guest network should be on the 192.168.8.0/24 subnet while our LAN is ...
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2answers
316 views

Blocking a botting URL to an Linux server running Apache

I have a webserver running OpenSUSE 11.1 and I need to block a URL. The reason I want to block a URL is because it seems to have a different IP address all the time, but the URL stays the same. I'd ...
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I need a traffic monitor for Linux, that only counts in a specific wireless network

I need a simple traffic monitor for Linux, that counts the traffic in a specific wireless network because I have volume restrictions on that one. I tried it using the following iptables rule: ...
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How do you add a MAC-based routing whitelist with DD-WRT and the OpenVPN client?

I have an OpenVPN client set up on my DD-WRT home router which maintains a VPN into my workplace. Slight problem: I don't want random lusers who access my wireless AP to have access to my company's ...
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1answer
575 views

Fedora 14 system-config-firewall-tui gone?

On Fedora I used to be abble to configure custom ports into the Firewall by going to setup and following the required steps till I got to something like this: Well that menu is here no more. I can ...
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Properly portforwarding the external IP with iptables

I am trying to forward all the incoming internet/LAN requests on port 80 to my local machine (running Apache), current iptables work (forward incoming internet traffic to my desktop, but if I try to ...
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Ubuntu 11.04 server iptables port forwarding

I'm pretty new to iptables. My server has two Ethernet cards (eth0, eth1) and an ADSL router that is in bridge mode connected to the eth0 which created ppp0 when dialed. I'm trying to forward ...
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Rackspace Firewall/Gateway Setup

I have rackspace account and wish to have this sort of setup: Firewall/Gateway eth0 - Public IP (56.X.X.X) eth1 - Private IP (10.X.X.X) Ubuntu 10.10. Accepts connections from the internet and ...
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iptables openvpn forward selectively from eth to tun

Simple for those who know, indecipherable for those who don't... I'm running openVPN on (hypothetical) 66.66.66.66, I want to FORWARD incoming traffic, arriving on interface eth0 to interface tun0. ...
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How do I get an iptables redirect to survive a reboot on SuSE 11?

I've set up iptables to forward from port 80 to port 8090: iptables -t nat -I PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8090 However the redirect is gone after rebooting. What's the ...
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2answers
233 views

Blocking ports with iptables

I have a server with multiple interfaces (IPs). I'd like to block all ports on one of the IPs (I don't want to change anything for other IPs/interfaces), but allow outgoing connections from it. For ...
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Can ipmasq and ufw be used together?

If both ufw and ipmasq manipulate iptables, can I use ipmasq for a quick easy setup and then use ufw afterwards to add security or will the two just trample all over the iptables "stuff"? I'm playing ...
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453 views

iptables drop fake ip packets

I'm trying to drop all packets from the internet that use a fake ip address so they appear to come locally. Do I need both lines or only the first ? --append INPUT ! --in-interface lo --source ...
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iptables rules revert on Ubuntu

I'm using iptables on Ubuntu 10.04 and whenever I set iptables rules they will revert after a while. I set them with iptables -I INPUT or iptables -D INPUT and they work immediately and I see them in ...
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1answer
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Disable or block outgoing email

To do web site testing, how can I disable or block the Centos server to not send out emails. Now, if I run in command line mail xxx@gmail.com I can send out emails. This is not good for website ...
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iptables restrict ssh session by mac address

I'm in the process of restricting access to my Linux production box, where ssh access needs to be limited to only a few MAC addresses. I've followed the instructions outlined in this guide and ran ...
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Setting up a Linux server with a public Static IP

I have setup a Ubuntu Linux server in an office. It should have a public IP so that outside users can access the internet. Currently, it is set with a public IP, but is it supposed to have a local ...
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1answer
852 views

Iptables prerouting and IP forwarding

I have a linux machine used as gateway for a Win XP machine. Both are in Virtual machine for testing purpose. Now I want to trick the Win XP user (me) with the forwarding of an IP address: I want to ...
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351 views

Is this firewall completely secure?

I'd like to know if there's any holes/flaws in this firewall setup. I want to lock down the server as much as possible so it is impossible to hack in to. The only services running are openvpn and ssh. ...
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751 views

How evade firewall port blocking?

I have a serious problem with my institute's firewall. I have a Rackspace Cloud server instance that is configured to accept SSH connections on port 6xxx. When I was using port 22 there wasn't any ...
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1answer
571 views

Removing/Disabling Firewall on Linux CentOs seem to happen temporarily

I tried following the instructions in this link to disable and remove iptables firewall using commands: # service iptables save # service iptables stop # chkconfig iptables off # iptables -F # ...
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1answer
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iptables equivalent in windows-xp,win7?

I want to do port forwarding in win7,what's the iptables equivalent in win7?
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1answer
516 views

Save iptables when iptables-save doesn't exist?

I'm working on a Soekris net4801 that is running an unknown distro of Linux. The kernel is 2.4.29, and iptables is v1.3.4. I can't work out how to save the iptables. I searched the whole system for ...
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iptables for transparent TCP proxy

Here's my situation. I have an iPad, a TiVo, and an dd-wrt router on my network, along with a machine that I'd like to use to sniff/decrypt draffic between the iPad and the TiVo. The iPad has an app ...
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1answer
673 views

Feedback to router users during access-restricted hours for DD-WRT

Following router schedule rules that I change often, the stock firmware on my D-Link 825NA rev. B redirects HTTP requests to a built-in "Access denied!" warning at appointed times. I just upgraded ...
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442 views

Firewalling all incoming traffic with custom rules

How do you automatically block all incoming traffic by creating custom rule for every connection (in real time) using iptables? To clarify - the situation is that my linux box is being DDOSed via ...
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Howto compile a kernel module on CentOS [required packages]

What yum commands do I need to get available packages installed on CentOS to build a iptables MATCH kernel module.
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872 views

Internal working of rules in forward chain for NAT

I am trying to understand how exactly NAT works to solve another bigger problem, here is my linux box setup: Interface eth0 connected to internet (public IP address) eth1 connected to local network ...
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1answer
993 views

loopback error, home network

I've setup my router to forward port 80 through to my computer, so I can access it from a dyndns.org domain. The domain and the ip both seem to be totally working, externally (can access it from ...
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1answer
395 views

Linux box acting as wireless access point to share the internet connection

A linux machine is connected to internet over two interfaces ppp0 and ppp1 using two modems. Also this machine acts as wireless access point through an interface say, eth0 with ip address 192.168.1.1 ...
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Home network to accept only certain MAC addresses from LAN

I have Ubuntu 10 as router with WAN(eth0) and LAN(eth1). How can I restric eth1 to accept only packets from certain MAC addresses and drop the rest? I am also about to setup DHCP to certain MAC ...