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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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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522 views

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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How to install firewall script in Ubuntu?

https://help.ubuntu.com/community/Router/Firewall In the link above there is a firewall script described. How can I install this script in Ubuntu 10.0.4 desktop?
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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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1answer
581 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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926 views

iptables and NetworkManager on Ubuntu

I want to use iptables configuration on my Ubuntu 10.0.4 desktop, however I read that Network Manager and iptables have some conflicts. Should I uninstall NetworkManager? If yes, how? ...
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234 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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246 views

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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93 views

Network problems that might be related to NAT

I have an odd setup where there is a router(Router 2) routing between network network 1 and network 2. One router(Router 1) with nat for internet access that routes between internet and network 1. ...
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470 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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392 views

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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527 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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Fedora iptables error

I recently installed Fedora 13 and receive this Boot message: iptables: Applying firewall rules: iptables-restore: line 14 failed I am new to Linux and need help in figuring out how to fix ...
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3answers
2k views

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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2answers
4k views

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
258 views

One website not connecting over shared connection

A website is not opening on a computer that's connected via shared connection (not exactly "shared"). Pinging the website gets Packet filtered message. The setup of my home network is done by Ubuntu ...
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2answers
758 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
858 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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113 views

how do i set up this firewall?

i use fedora 13, and i have firewall turned off now. but i want to allow all incoming connections and outgoing connections except to a port P. i want to allow connection to port P only from certain ...
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440 views

iptables - router configuration

I have a router that I am customizing settings for. I want to only allow SSH from the internal network and drop everything else. This is what I have so far. I tried it and I had to reset my router ...
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578 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
1k 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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608 views

Quotas with iptables

pkts bytes target prot opt in out source destination 12770 2385K ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 quota: 2000000 bytes 0 ...
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911 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
399 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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1answer
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tc / iproute2, how to list the configuration

This is my first time using traffic shaping and I am wondering how I can list the rules I applied like you can with iptables? Walter
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320 views

how do I forward *only* http proxy across vlans?

My router has two bridges, br0 and br1. I'm sharing wifi access, and the guest subnet will be 192.168.2.x. The home subnet will be 192.168.1.x. I want all traffic destined for port 80 from the ...
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2k views

DD-WRT OpenVPN client - cannot get “lan” connected device to route traffic

I have OpenVPN client setup on DD-WRT openvpn small. client connects and can use traceroute to verify everything is tunneling out the openvpn connection. ip_forward is 1. iptables -t nat -A ...
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1answer
589 views

iptables firewall rules not allowing ssh from lan to DMZ

Chain INPUT (policy ACCEPT) target prot opt source destination REJECT tcp -- anywhere anywhere tcp dpt:www reject-with tcp-reset REJECT tcp ...
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1answer
507 views

IP Tables won't save the rule

I'm using ArchLinux and I have an IP tables rule that I know works (from my other server), and it's in /etc/iptables/iptables.rules, it's the only rule set in that directory. I run, ...
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537 views

Why does my Tomato router seem to behave badly as time passes

I've set up a Firewall script on my Tomato router (a WRT54G 2.0, actually) that seems to behave correctly at start, but after one or two days, it seems that the script does not work anymore... The ...
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1answer
666 views

Ubuntu 9.04, Firestarter complaints even behind the NAT router

I'm behind a router. In router config, I blocked: all (inbound and outbound) UDP inbound ICMP Local iptables are configures with Firestarter wizard: block all incoming connections allow all ...
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1answer
153 views

no websites loading using iptables nat

I'm using a 3G modem whilst o2 tranfer over adsl. trouble is no websites load but I can resolve domains. I enabled masquerade on the PPP0 ( modem) interface. added the server as default route for all ...
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How to block access to a website on Lucid Lynx?

I am trying to block a few websites on a lucid lynx, I tried editing /etc/hosts and that blocks access via url but the site still open if I enter the ip on the browser, how can I block ip access also? ...
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Why after Accepting Ports 20 and 21 in iptables are they still closed?

I am trying to open the FTP Ports on my server. I have vsftpd installed on the server already. However I am unable to reach the server on ports 20 and 21 Somehow it is allowing me to access port 21 ...
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2answers
286 views

Logging communication between two VMs

I'm trying to set up "malware lab" described in this paper. So far, I've set up Windows guest system, adding one Host-only Network adapter, and setting this (sorry if the names aren't exactely ...
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157 views

How to setting up iptables for traffic fowarding on port 80 from specific sources

Im running a web server on port80, but i want traffic coming from ip 212.333.111.222 on port 80 to be fowarded to port 9020 on the same server that my web server is rinning at that is my sshd port
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iptables: separate clients from each other

is there a way to separate clients in a subnet so that they cannot reach each other? The infrastructure currently looks like this: 192.168.0.1/24 Gateway, a CentOS box with iptables. ...
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How to use FQDN in firewall rules for GNU/Linux?

I'm trying to setup a firewall for one of GNU/Linux systems. AFAIK, iptables and its ilk cannot make use of FQDNs in their configuration, since they're expected to be operational before the network ...