Iptables is used to set up, maintain, and inspect the tables of IP packet filter rules in the Linux kernel.

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Is NAT iptables available in 11.04?

I have an Ubuntu 11.04. I wanted to play around with iptables rules. But I don't see it installed. When I did: sudo iptables -t nat -F chain This is what it returned: iptables v1.4.10: can't ...
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1answer
1k views

Trouble setting up openVPN/VPN

I'm having trouble setting up a VPN on my VPS that's running Ubuntu 11.04. I'm been following this guide http://tipupdate.com/how-to-install-openvpn-on-ubuntu-vps/ I'm able to start the VPN, but the ...
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2answers
38k views

How to save rules of the iptables? [duplicate]

I create the rules to iptables. But, when I restart the computer, the rules don't work! How to save the rules on Ubuntu ? The was problem solved! do: After of the write the commands iptables, do: ...
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1answer
373 views

ubuntu as multi port router

If I have an 4 (or more) ethernet port linux box, How to setup it as router to handle 4 class c subnet ? for example, eth0 => 192.168.1.0/24, eth1 => 192.168.2.0/24, eth2 => 192.168.3.0/24, eth3 => ...
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1answer
1k views

Iptables Not Blocking User

iptables seems to not want to block a user. I'm using a remastered 10.04 live and Firestarter as a firewall. I've made no fundamental changes to the distro, except to update, upgrade and added this ...
4
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1answer
4k views

Do I need to restore iptable rules everytime on boot?

Every time I reboot I loose the iptables rules that took me so looong to enter. I know I can save them and restore them on boot, but is there anyway to save them forever? Do I really need to restore ...
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2answers
4k views

iptables mac address filtering not work

I block every port default by ufw and add iptables rules like this: sudo iptables -A INPUT -p tcp --dport 1723 -m mac --mac-source 00:11:22:33:44:55 -j ACCEPT then I list iptables INPUT rules: ...
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0answers
289 views

Cannot FTP without simultaneous SSH connection? [closed]

I'm trying to set up an old box as a backup server (running 10.04.4 LTS). I intend to use 3rd party software on my PC to periodically connect to my server via FTP(S) and to mirror certain files. For ...
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1answer
1k views

Log destination IP with iptables

I want to log destination IP addresses in my Ubuntu router. I have two network cards eth0 - 10.0.101.254 eth1 - 10.0.101.253 10.0.101.254 is the GW for all hosts on my network. The router ...
0
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1answer
301 views

Access VPN from home is fine but not outside via 3G

I'm a real Ubuntu newbie but at the school where I work I managed to install Ubuntu then install pptpd. I was feeling very pleased with myself when last evening from home with my Apple iPhone through ...
3
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1answer
3k views

Port forward to a port on the same machine

I used to run a service on port 25570 I'm now changing it to run on port 25565 but I still want people who try to access it on the old port to have access to the service. So I'd like to forward port ...
1
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0answers
553 views

PPTP Server - Clients still have original IP [closed]

I have a VPS with an OpenVPN server configured and running without a hitch. However, since I want to be able to use it as a VPN server for my iPhone as well, I've decided to switch to PPTP. I ...
2
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1answer
532 views

Looking for IPTABLES and UFW readily available, the best proven rules

ok i am up with UBUNTU finally, and liked the distro! particularly ufw, synaptic and software manager. as i am pretty blind newbie to linux, i need some help securing Ubuntu desktop. I've gone ...
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3answers
4k views

Is there a recommended default iptables setup?

I've been using ubuntu server for a while, however I have never really invested time into iptables. I was wondering if there was a recommended way to setup iptables on a basic server intall. An ...
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3answers
1k views

Why is Ubuntu permissive with outgoing connections by default?

I am pretty newbie to Linux, as most of computers for resources in my school use Linux, I just installed Ubuntu to learn. By default iptables and ufw sets policy as under: IPTABLES -P INPUT DROP ...
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1answer
7k views

Redirect packages directed to port 5000 to another port

I'm trying to use eboard to connect to the FICS servers (http://www.freechess.org), but it fails because port 5000 is blocked (company firewall). However, I can connect to the server through the ...
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1answer
2k views

How can I set up GUFW so that only firefox connects to the internet

I only want http, https and DNS to be open. I'm having troubles with setting up port ranges in the UFW GUI. How do I input configs into the feilds? Basically, something along the lines of this, but ...
2
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0answers
597 views

Is there an application firewall for Linux, like ZoneAlarm [duplicate]

Possible Duplicate: How to control internet access for each program? I've tried Firestarter and Ufw, but in the end, decided to write my own iptables scripts. I basically let http and ...
2
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1answer
393 views

Shorewall is breaking packets/sessions when connecting out to internet

I am happy to forward any further data if required like firewall rules etc. Would appreciate if someone can skim through my config and see if there are any glaring errors. Problem: Everything working ...
0
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1answer
435 views

Iptables rule for server accessed remotely via DHCP

Sorry to ask this question - but I have been browsing forums and threads on this subject and seem to confuse myself more than actually getting any clarity. All I need is a short and concise answer for ...
2
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1answer
729 views

iptables resets when server reboots

Everytime my server reboots it seems I have to reset my iptables to default, I used to use firestarter but removed it a while ago. Is there any settings that are making iptables change when the server ...
3
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1answer
8k views

iptables-restore failing to load my rules

I've been searching around for some time now, but nothing solves my problem. I'm setting up a mail server, but when writing to the iptables, I get an error: iptables-restore: line 2 failed. I'm ...
2
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1answer
1k views

No client internet access when setting up these iptables rules

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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1answer
2k views

How many instructions can be stuffed into iptables without loosing system sanity?

Say one wishes to have a list of blocked IP addresses. I have seen the following example script: BLOCKDB="/path/to/ip.blocked.file" # omit comments lines IPS=$(grep -Ev "^#" $BLOCKDB) for i in $IPS ...
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1answer
3k views

Squid proxy server (or iptables) will not let my users send or receive mail

I have an Ubuntu 10.04 box that was once configured as Squid Transparent Proxy. Navigation was perfect: my windows clients had no troubles. The problem I had was that users were not able send or ...
2
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1answer
4k views

Which INPUT rules do I need to add to iptables so apt (apt-get, aptitude) can work (update, upgrade, search, install)?

I need to use aptitude to update and install software but it fails. It says... 0% [Connecting to archive.ubuntu.com] ...and halts. I need to type CTRL-C to move out. I'm using Ubuntu Server 10.04 ...
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3answers
17k views

How can I make a specific set of iptables rules permanent?

Is there a "best practice" or standard to make a few iptables rules permanent? I mean: automatically applied upon a system reboot? I am using a VPS with Ubuntu Server 10.04 LTS (Lucid Lynx). Thank ...
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3answers
1k views

Block anything from certain IP, injected from ISP when tethering from phone

My ISP injects JavaScript files - most notabily bmi.js - and certain other unwanted additions to web requests when tethering from my phone. It would be OK if the JavaScript was useful, but it is ...
2
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1answer
813 views

iptables on desktop

I have some iptables rules and a policy that I want to apply to my desktop. Where is the the configuration file that will make these changes permanent? Is there any issues with using iptables and ...
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1answer
2k views

How do I add a dyndns alias to my Iptables?

First of all: I'm aware of this old question: iptables allow dyndns domain name and auto update rules But somehow it doesn't help me. The Problem Iptables on my work pc are configured to drop all ...
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2answers
3k views

potential ufw and fail2ban conflicts

Will running both fail2ban and ufw cause problems? I noticed that fail2ban modifies iptables rules, but ufw already has a ton of iptables rules defined... so I'm not sure if fail2ban will mess these ...
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3answers
4k views

Bash Script: catching errors in a block of statements

I have a large iptables ruleset that I manage with my own bash script. Most of the commands in the script are simple, single-statment iptables commands. I am trying to improve the script by adding ...
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1answer
153 views

What should the source be when using OpenVPN?

I'm trying to use OpenVPN on my Ubuntu 10 VPS. I'm trying to route my traffic using this command: iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -j SNAT -to The error I get is: iptables v1.4.4: ...
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0answers
343 views

Set and save iptable rules forver! [closed]

I'd like to set and save forever this Iptables rule, but i don't how i can do: iptables -I INPUT -p icmp --icmp-type 8 -j DROP This rule is very useful because it blocks ping requests and my pc is ...
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9answers
14k views

How to control internet access for each program?

I would like to use a software to control which program may connect to the internet. I know that this behaviour is associated with the word "firewall", but some Linux users are very upset if somebody ...
2
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1answer
4k views

How do I load iptable kernel modules onto a VPS?

I have two servers, using one for prod and one for dev. They are with different providers, and one is running Xen and the other OpenVZ (both running Ubuntu but 8.04 and 10.10 respectively). I've ...
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2answers
281 views

How do I interfere with domain access?

I've just installed Self Control for Ubuntu. It looks like it just tweaks /etc/hosts and defines some rules in iptables. Some sites aren't getting blocked, and I think it's because they're ...
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1answer
575 views

When do iptables rules become active?

I have an script that bans selected IPs from my server. Example: iptables -A INPUT -s 123.123.123.123 -j DROP My question is: When this rule will start working? I'm asking this, because yesterday ...
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1answer
693 views

The problem of Virtual LAN and iptables's configuration

I added the Virtual LAN eth0:3 in /etc/network/interfaces ifconfig eth0 Link encap:Ethernet Hwaddr:00:1e:ec:11:97:dc inet address:10.16.31.179 broadcast:10.16.31.255 ...
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5answers
19k views

How to secure ubuntu server from bruteforce ssh attacks?

I have my passwords secure, but I heard people complaining about perfomance of a server going down drastically when a bruteforce attack is taking place. How can I secure my ubuntu 10.10 server from ...
1
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1answer
872 views

Iptables unresolved dependencies

I'm trying to setup OpenVPN Access Server on a VPS running Ubuntu 9.10 for a friend so she can play games from her uni campus. The problem is I keep running into this error when trying to start ...
10
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1answer
30k views

Redirect requests to my external IP/port to a different external IP/port?

Is it possible to redirect connections to a specific IP/port to an external IP/port? Example: Server A has the external IP xxx.xxx.xxx.xxx Server B has the external IP yyy.yyy.yyy.yyy User sends a ...
4
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5answers
13k views

How can I fix the iptables error message “unable to initialize table 'filter'”?

When I try to use iptables command on one of my Rackspace cloud server, I'm getting the following error. In an attempt to apply iptables rules with iptables-apply -t 120 /etc/iptables.rules and ...
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2answers
5k views

What are fail2ban's log iptables “returned NNN” entries? (Fail2ban is failing to ban)

In my fail2ban.log there are some entries the meaning of which I don't understand (and haven't found searching around)... I have several "jails", and I have created one particular one that bans IP's ...
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4answers
14k views

How can I block ping requests with IPTables?

and stealth specific ports?
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3answers
47k views

Reloading iptables

I made changes to iptables config file in /etc/iptables/filter in ubuntu and want to reload them. I read the man page and also googled but couldn't find the information. Any help will be appreciated. ...
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2answers
3k views

iptables rule to force all browsers to use proxy

I have installed squid as my proxy server in Ubuntu 10.04 standalone system which has a single NIC. Why i have installed Squid in a standalone system is because of my friends who uses my system to ...
2
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1answer
2k views

Weird issue with iptables redirection

I am trying to redirect all incoming traffic on UDP port 5060 to port 56790, and all outgoing traffic from 5060 to the port 56789. I used these iptables rules: iptables -t nat -I PREROUTING -p udp ! ...
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2answers
3k views

iptables allow dyndns domain name and auto update rules

I have registered with dyndns domain for my dynamically changing public ip address to use with iptable rules. On a server I've allowed some ports for this domain in the iptables configuration like the ...
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2answers
1k views

iptables & nmap on ubuntu

The following are my iptable rules on a ubuntu cloud server: cat /etc/iptables.rules: *filter :INPUT DROP [598:41912] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [456:35354] -A INPUT -i lo -j ...