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

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Adding firewall rule makes multiple entries

I am trying to add a rule to my Ubuntu 14 iptables to allow NTP (123) though using the command for allowing Incoming Traffic on Specific Ports Basic iptables How to? Here is my command: sudo ...
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2answers
19 views

Unable to share internet via NAT connection sharing

I've been using my Jetson TK1 Remotely via ssh and NAT connection sharing as described here. Earlier everything was working perfectly, but now whenever I try to share my internet connection by running ...
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25 views

Route only traffic on specific port through VPN

I would like to route only traffic on a specific Port. In my case for torrents through a VPN. For Transmission the port is 51413 I think. I only found tutorials how to set this up on a router but I ...
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1answer
31 views

iptables - redirect DNS queries

I already have the following iptables rules applied in order to masq all of the wlan1 traffic through wlan0. *filter :INPUT ACCEPT [48:6144] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [47:6078] -A INPUT -i ...
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1answer
148 views

Why does my firewall reset upon reboot?

I host gameservers on my dedicated server and was setting up the firewall a few days ago (had to set everything up again, hard drive failed and I forgot to back-up). Everything ran fine, firewall ...
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1answer
57 views

Can't connect to a server via SSH (with my PC only) [on hold]

For some days I'm experiencing issues with SSH on my machine (I guess after having installed some software that I don't remember). It's very problematic as I use Git to work on some code projects ...
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15 views

iptables reject issue

Ive tried adding a basic rule to my iptables to drop an IP that keeps establishing a connection. I must admit this is a vm and the image was from bitnami with many of the rules already configured. ...
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1answer
39 views

UFW - How to make it easier and what are stealth ports can UFW have these? [closed]

Let me show u what I jusat wasted 2 hours doing: To Action From -- ------ ---- 22 REJECT Anywhere 23/tcp ...
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27 views

Setting up iptables of poptop pptp vpn on Ubuntu

The VPS I bought has an additional ip address, which shows as eth0:0. main ip -> eth0 second ip -> eth0:0 I want my pptp users to use the second ip to access internet. but I don't know how to do it. ...
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1answer
16 views

iptables nonexistent?

$ iptables sh: 1: iptables: not found $ sudo iptables [sudo] password for [redacted]: sudo: iptables: command not found $ /sbin/iptables sh: 3: /sbin/iptables: not found $ sudo /sbin/iptables sudo: ...
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1answer
65 views

Forwarding interfaces inside a docker container

I have created a docker container executing the following command docker run -it --net=none --cap-add=NET_ADMIN --name firewall ubuntu /bin/bash after I have attached it two interfaces eth0 and ...
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29 views

Setting Up a Routing Table for a Router

I have two network interfaces on my server. They are: eth0 - 192.168.1.2/24 gateway 192.168.1.254 eth1 - 192.168.2.254/24 no gateway as this interface is the gateway for this subnet I want ...
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17 views

Iptables: some ports are closed despite being open by my iptables; can it be something else?

Beginner question. I set up the following iptables rules: #!/bin/sh # Réinitialise les règles sudo iptables -t filter -F sudo iptables -t filter -X # Bloque tout le trafic sudo iptables -t ...
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1answer
87 views

ERROR: problem running ufw-init

I tried setting up ufw on my remote Ubuntu 14.04 server so i installed it and allowed ssh with the command sudo ufw allow ssh after that I tried to enable ufw but I get the following error: ...
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1answer
29 views

nmap showing open ports despite port close

I just set up my iptables with a DROP policy: -P INPUT DROP -P FORWARD DROP -P OUTPUT DROP -N fail2ban-ssh -A INPUT -p tcp -m multiport --dports 22 -j fail2ban-ssh -A INPUT -m state --state ...
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3answers
65 views

Ubuntu / Apache2: I cannot open port 443 [duplicate]

I am trying to install a SSL certificat on my Ubuntu 14 server (using apache 2). For some reason the port 443 appears to be closed I installed and enable ssl /etc/apache2/ports.conf is as ...
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21 views

How many rules can iptable handle in different machin?

I am trying to design a traffic shaping scenario . I am using iptables to create filters but i must create 80,000 rules. I want to know , how many rules iptables can handle ? I read different articles ...
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26 views

How to redirect TCP traffic from one virtual machine to another in Linux?

What is the simplest way to redirect all TCP traffic from one virtual machine to another in Ubuntu Linux and reverse? And what type of connection I suppose to use in VirtualBox?
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1answer
53 views

How can I allow ap-hotspot in ufw Ubuntu 14.04?

When ufw is enable android stuck in obtaining ip address and cannot connect to wifi. I try sudo ufw allow dhclient and sudo ufw allow dnsmasq bot both had ERROR: Could not find a profile matching ...
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1answer
71 views

IPTABLES - Forwarding 80 to 8080 to vagrant's apache

I was trying to forward my 80 access to 8080 with IPTABLES without success, then I read this answer And it finally worked for me, after all the IPTABLES configurations I tried this command made it.. ...
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2answers
69 views

iptables/netfilter: What's the difference between PREROUTING and FORWARD?

I am trying to understand how this system works and I have problems to understand the difference between using NAT PREROUTING or filter FORWARD. From what I understand, the PREROUTE can send the ...
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1answer
49 views

loading “explicit” iptables rules on boot or interface up

I'like to load iptables rules on boot or interface going up on Ubuntu. Made a search on StackExchange and other places and looks like the most commonly agreed approach is either use ...
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19 views

set up iptables of poptop pptp on ubuntu

The VPS I bought have an additional ip address, which is shows as eth0:0. I want my pptp users to use this ip to access internet. but I don't know how to do it. I am using this right now -A ...
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1answer
84 views

Trying to block YouTube

I've tried two different commands in IPTables to block YouTube. They briefly work, but then, hours later, or the next day, I test it again, only to find that it comes through when I DON'T want it to. ...
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1answer
50 views

Configuring NAT with ufw instead iptables

I want to apply this iptables rule: iptables -t nat -A PREROUTING -d 87.13.180.182 -j DNAT --to-destination 192.168.0.13 (87blabla is my public ip and 192blabla is my private ip). People ...
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1answer
49 views

Can't connect from outside to my apache webserver using a free dynamic dns and IP

I am running ubuntu 12.04 and a web server apache v.2.2 on port 80.My connection to internet is based on a dynamic ip and in order to connect to my web server I want to use a free dynamic dns ...
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1answer
60 views

How to open local apache website to the world? [closed]

I'm trying to enable HTTP port to be accessible from outside of my network. I currently have a public IP from my ISP. Do I need to set this up using iptables? sudo iptables -vL -n Chain INPUT ...
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1answer
41 views

How would I use ulogd2 on Ubuntu with IPv6?

I am trying to make use of ulogd2 (package ulogd version 2.0.3-1ubuntu2) on my Ubuntu server and I run into the problem that ip6tables fails: $ ip6tables -A INPUT -m limit --limit 5/sec --limit-burst ...
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1answer
57 views

How to redirect URL:PORT traffic to multiple external IP:Port?

Currently, I'm using iptables to redirect incoming requests for "website.com:27015" to "xx.xx.xx.xx:27015". Problem is, since iptables redirects via the port 27015, I can only redirect to one single ...
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0answers
30 views

VSFTPD acess only localhost

I configured a ftp server but I can't acess it. If I try ftp localhost in server terminal it works but if I try ftp SERVERIP it doesn't work....neither from filezilla. The server doesn't have ...
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1answer
42 views

Unable to run iptables commands

When I try running sudo iptables -L (or any other iptables related command) I receive the following error: modprobe: ERROR: could not insert 'ip_tables': Cannot allocate memory iptables v1.4.21: ...
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1answer
420 views

How can I open port 80?

I'm new in Ubuntu, and I'm trying to open port 80. I have already set my router in order to do so, and I also set ufw. Status: active To Action From [ 1] 22/tcp ...
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1answer
92 views

Forwarding ports with iptables not working?

I have an ubuntu server (14.04.1) which is asking as a router for my network. It has an internet facing interface, eth0, and a second interface, eth1, for connecting to my 10.0.0.0 network. I am ...
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3answers
85 views

Where are my iptables?

I ran the code: iptables-save -t nat -A PREROUTING -d 79.3.191.226 -j DNAT --to-destination 192.168.0.14 But I don't know if it worked since I cannot find the iptables file inside my directory. ...
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29 views

Redirect traffic between two Virtual Machines using iptables

The situation is this: I have an host machine running ubuntu and 2 Virtual Machines (Ubuntu and Windows) running in host-mode, so that I can see them from the host machine. Now what I want to do is ...
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30 views

Allowing Longview in UFW firewall; how do these iptable rules translate to UFW-commands?

Linode has some documentation on allowing its product "longview" to go through the firewall. It offers two commands for iptables: iptables -I INPUT -s longview.linode.com -j ACCEPT iptables -I OUTPUT ...
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1answer
72 views

dport is not working on iptables command

In terminal I type : iptables -A INPUT --dport 443 -j DROP And it tells me : iptables v1.4.21: unknown option "--dport" what is wrong with --dport?
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93 views

ufw rules don't block deluge

I'm trying to keep deluged on my headless Ubuntu Server 14.04.1 from functioning when the server isn't connected to a VPN (I know many threads exist discussing the best way to accomplish that; I'm not ...
0
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1answer
83 views

linux gateway / firewall IPtables config

The KVM host is acting as a gateway / firewall for all of the virtual machine's it runs. It has a /26 public IP space configured on LAN interface em1: 1.1.1.1/26 It has a /30 rfc1918 IP configured on ...
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1answer
29 views

Can Using Git over SSH be distinguished from normal SSH traffic?

So, I set up my iptables configuration so that repeated attempts to SSH into my private server cause a blacklist. # iptables -N SSH # iptables -A INPUT -p tcp --dport ssh -m conntrack --ctstate NEW ...
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2answers
137 views

Restricting internet access of some client systems of LAN to a few websites using ubuntu gateway

How to limit internet access of most systems in my LAN to a few websites and block all the other websites? Also want to bypass that restrictions for some systems. All systems have static IP address ...
0
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2answers
75 views

Can I use iptables to forward vm guest requests to host

This is a bit complicated, but I have a Windows 7 vm (virtualbox) and I need create a persistent connection to the MySQL instance on my host machine. Binding... I can do this using mysql address ...
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0answers
87 views

routing through ubuntu server

Im having issues with routing from Windows/Linux/Mac machine through server and from desired interface out. So this is my configuration: My example will be Ubuntu -> Ubuntu -> out First machine: ...
0
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1answer
85 views

How to allow a WAN connection via a forward port?

My home internet connection has a static IP address (eg: 123.123.123.123) I have configured my router to forward port 9000 to an internal host (192.168.1.101), which is running Ubuntu 14-04. I run ...
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16 views

Is there a backport of ulogd2 for 12.04 precise?

I have a server with Ubuntu 12.04 running on Rackspace cloud, configured to use the latest kernel. A week ago or so I rebooted the server and it booted on a new kernel 3.17.1 (that had been released ...
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1answer
90 views

iptables - unable to initialize table filter

I have a firewall file saved in /etc/firewall.conf. Everything is ok, I can use it for "iptables-restore /etc/firewall.conf" with success. So, starting from this file, I created a php script(that ...
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16 views

No able to connect to WiFi after installing iptables-persistent

I am using ubuntu 14.04. I was trying out how to add entries to iptables. I executed the following commamd. sudo iptables -A INPUT -p tcp --dport 80 -j ACCEPT To persistent the above changes I ...
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0answers
53 views

Using iptables to detecting SSLv2 and SSLv3 initial connection packets, drop them, and log them

This is going to sound like an odd issue, but I'm trying to detect SSLv2 and SSLv3 connection attempts, log the packets so I can find the source for those IPs, and then drop the packets silently. Is ...
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0answers
81 views

Blocking specific programs from accessing the internet isn't working (iptables / apparmor) [closed]

I'm using this guide to try to block a few programs from sending or receiving data from anything other than 127.0.0.1, but it's not working. First off, the suggested way of only allowing an IP block ...
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27 views

What is wrong with knockd?

I am trying to implement port knocking for ssh service on my personal server. I have two other public services that will always be open. My iptables rules look like this: Chain INPUT (policy DROP 0 ...