iptables allow creation of rules to define packet filtering behavior.

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83 views

Minimize game server delay with iptables

I have a debian 7 server hosted by Google Cloud running a game server and a rails server. The rails server run on port 80 and the game server on port 8000. I wanna apply a network rule that allow ...
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1answer
171 views

record contents of packets dropped in iptables

I'm trying to find a way to record the entire contents of packets (possibly with tcpdump) that have been dropped according to rules in iptables. At present, I have a rule to log these packets (with a ...
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27 views

Initial iptable rule and knockd operation in vps

Today I launched a vps with Debian 7 x64 and started playing around with it. I installed xampp as well as knock daemon to get my hands dirty. So, all I wanted to do was to actually block all requests ...
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1answer
32 views

How to configure correctly iptables for run Maples with a blocked internet connection?

I would like to be able to run Maple with a blocked internet connection. For doing so I set my iptables by doing something like this for user joe: sudo iptables -A OUTPUT -m owner --uid-owner joe -j ...
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0answers
75 views

I Need Find A Mac Address from a client connected to my Teamspeak

I have a dedicated server and from it I am running a teamspeak 3 server. In teamspeak server there is a client who need to be banned. I have banned him from teamspeak but if you change your windows ...
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33 views

iptables rules to issue with tftp

My requirement is to add iptables rules in such a to allow tftp traffic(as a client) and drop everything else. And in fact using the iptc library programmatically using C code. To start with I tried ...
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2answers
46 views

iptables is ignoring rules?

I've found some strange traffic through tcpdump (traffic is ongoing always): 13:00:13.203754 IP 1.2.3.4.1028 > 188.113.188.16.56881: UDP, length 103 13:00:13.204396 IP 1.2.3.4.1028 > ...
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134 views

Slackware internet gateway with iptables / poor browsing performance

I am running a dual core headless computer as internet gateway via pppoe with two NICs. eth1 (internet interface) no ip, no dhcp eth0 (LAN interface) - 192.168.0.100 static ppp0 - dynamic ip ...
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72 views

Using a VPN client as a VPN gateway

I would like host 1 to use host 2 as a gateway to the remote host 3. I have scoured the web looking for a solution, but it doesn't seem to work for me. VPN client software is ike (shrewSoft VPN) is ...
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0answers
51 views

Set user-wide network proxy settings on Ubuntu (without restart)

Is there any reliable way to set proxy settings user-wide for all traffic on Ubuntu? As far I'm using {http|https|ftp}_proxy variables in /home/$USER/.bashrc which is nice but there's some issues: ...
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97 views

Route VPN traffic through different proxies

I want to setup VPN server and route (based on my routing algorithm) all traffic through different proxy servers. Let's say I have one host, with many users, connected to my VPN. I want to route all ...
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22 views

iptables and applications

I'm trying to set up a little download box. I currently have pyLoadCore, Transmission-daemon and openvpn all running on raspbian (raspberry pi running headless). My problem arises when I have openvpn ...
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1answer
33 views

Iptable forward interfaces for gateway machine

I have two Ethernet interface being configured to use as system gateway ex: eth1: 10.10.1.0 eth2: 10.10.2.0 I want to forward all the packets which are coming to the 10.10.2.0 gateway contacting ...
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1answer
200 views

viewing firewalld logs via remote login to CentOS 7 server

I have firewalld installed in a remote CentOS server. When I log into the server over the internet as root, I type the following command to access the firewalld logs: journalctl ...
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0answers
432 views

Network firewall on CentOS, host cannot be resolved?

I have a centos machine and I am trying install some dependencies using yum. When I do this I keep getting a message saying the host cannot be resolved. I was told the previous person that used the ...
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0answers
109 views

iptables IP address (source and destination IP address) mangling

I tried to understand the concept of iptables mangling part, but somehow failed to understand the IP header manipulative section. For example: Below is the system scenario which I'm trying to ...
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1answer
108 views

conntrack in iptables not working [closed]

I have tried to use conntrack in my iptables rules, however I keep getting an error. I've tried aminimal example with just one line and the error appears as well. admin@server:/home/admin/skrypty# ...
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2answers
124 views

Forward port 22 out a particular interface

The situation I'm in is where we have three separate interfaces on a particular machine. Each connected network only allows servers (by network-based routing/firewalling) to only offer particular ...
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0answers
142 views

how to route traffic on port to ip:port on linux?

I'm trying to route all traffic on port udp 5000 to udp 192.168.0.1:12333 with the following command: $ iptables -t nat -A PREROUTING -p udp -m udp --dport 5000 \ -j DNAT --to 192.168.0.1:12333 ...
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1answer
373 views

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 runs ...
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3answers
30 views

Why did this iptables rule block my webserver?

I was setting up Mathematica on a remote server, and needed access to the UI. I set up VNC according to http://wiki.centos.org/HowTos/VNC-Server , and got it working, which involved making an ...
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0answers
40 views

VPN tunnel to two services on two servers?

I've got 2 CentOS 6.5 servers, each running one service: server A: 10.140.54.1/27 running service MySQL port 3306 server B: 10.140.54.2/27 running service httpd port 443 Server B's httpd service ...
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99 views

iptables: can't open tcp port

I'm running a Raspberry PI B+: Linux pi 3.12.28+ #709 PREEMPT Mon Sep 8 15:28:00 BST 2014 armv6l GNU/Linux The Raspberry is connect via lan (dhcp. ip: 192.168.78.29) to the local network. I'm trying ...
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0answers
57 views

Transparent proxy to other IP of thousand ports

I was bought a service that only allow a IP, the IP that i say, only one, but I need use this from more IP's. I think that I can install in this computer a system to do a transparent proxy for ...
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1answer
100 views

Why are these connections not classified as “established” under conntrack?

I have the following rule for iptables: -A OUTPUT -m conntrack --ctstate ESTABLISHED -j ACCEPT such that outgoing connections not classified as established will be logged. Occasionally, the ...
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51 views

Port randomly closing (iptables)

I'm running CentOS 6.5 on a VPS and one of the services I have running is murmur/mumble (A voip application). The issue I'm having is that the port clients connect on will be open when I initially ...
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23 views

iptables packet header capture and compare

We are using multicast program to listen up multicast data from our provider, there are couple cases where the multicast having issue: 1. their server hang, hence no multicast data received from our ...
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0answers
145 views

how to open up socks/SSH on different network interfaces?

iptables -A PREROUTING -i usb0 -t mangle -p tcp --dport 8080 -j MARK --set-mark 1 iptables -L Chain INPUT (policy ACCEPT) target prot opt source destination Chain ...
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1answer
2k views

can not telnet to a server connection refuse

I have two server with these specifications: IP address: 192.168.1.94 IP address: 192.168.1.221 I want to telnet to the first one from the second one (to port 5029) but I get this error: ...
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0answers
72 views

How to route pakets from an aliased interface towards a gateway?

I'm having trouble setting up the following: Router IP: 192.168.1.1 PC Eth0 - 192.168.1.104 Eth0:1 - 10.0.0.1 (must be an alias) Besides ip_forward enabled, what should I add to iptables rules, so ...
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3answers
118 views

Bridge/Router with custom logic

I've a Linux box with 3 network adapaters, which I'd like to configure as follow: Adapter A is connected to computer A Adapter B is connected to computer B Adapter C is connected to the Internet. ...
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0answers
64 views

Forwarding DNS traffic for specific domain

I'm trying to control which IP address I use for DNS based on the domain string. I'm on Fedora with firewalld and have tried the command: firewall-cmd --direct --add-rule ipv4 filter PREROUTING 0 -t ...
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1answer
161 views

iptables NAT on Debian openvz

So i want to create a nat rule for an openVPN server. After getting trouble with the TAP/TUN Devices, it's finally working i think. Now i have to make a nat rule like so : >iptables -t nat -A ...
5
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1answer
331 views

How does a transparent SOCKS proxy know which destination IP to use?

There are two SOCKS proxies that I know about that support transparent proxying for any outgoing TCP connection: Tor and redsocks. Unlike HTTP proxies, these SOCKS proxies can transparently proxy any ...
2
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1answer
63 views

iptables, what is truly open?

We have an RSA appliance, I've reviewed the firewall rules on this appliance to determine what ports are enabled. To me, it looks like its wide open; but the vendor states that I am wrong about this, ...
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1answer
39 views

How to wrap iptables commands around Ruby webrick server going up and down in a single command/script?

I would like to use this Ruby WEBrick server solution for on-demand showcasing of some random web pages. So I set up some forwarding exception on my adsl modem local web interface(192.168.2.1). Then ...
2
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1answer
217 views

How to completely block a website like Facebook?

I'm trying to block Facebook access from my home system (Ubuntu). I could add facebook.com to /etc/hosts, but that would only prevent accessing facebook.com. There are many other ways I could use ...
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2answers
200 views

Is there a specific reason why iptables would return an exit code of 3 (instead of 1?) when executed without sufficient privileges?

I simply forgot to use sudo: usr@arch ~[0] $ iptables -L iptables v1.4.21: can't initialize iptables table `filter': Permission denied (you must be root) Perhaps iptables or your kernel needs to be ...
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1answer
109 views

Dovecot/Postfix mail server replies to [SYN] with [RST, ACK] when user attempts to connect (POP3). Likely iptables?

Currently I'm trying to troubleshoot an e-mail server that will allow users to send e-mail, but not log in to the server (POP3) or receive e-mail using their Outlook clients. Previously this was ...
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0answers
18 views

Making sense of this iptables http proxy config

I've never touched iptables before and I'm trying to understand exactly what these three lines do. I have ip_forward switched on and I know the end effect is that all traffic on eth0 is forwarded ...
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0answers
80 views

iptables rate limit error

This is on centos 6.5, I want to limit number of maximum connections using iptables: iptables -A INPUT -p tcp --syn --dport 80 -m connlimit --connlimit-above 15 --connlimit-mask 32 -j REJECT ...
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1answer
95 views

Can I forward all traffic on a port to a complete different IP address?

Here's my situation. I own a VPS that provides 3 public IPs / public interfaces. let's call these IP address V1 (on eth1), V2(on eth2) and V3 (on eth3) At home, I have a router. The home WAN IP is H. ...
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1answer
21 views

iptables fowarding rules

I have an iptables rule in the FORWARD section that looks like this: 17 0 0 CONFIRMED tcp -- * * 0.0.0.0/0 172.16.30.240 tcp spt:587 dpt:587 ctorigdst ...
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1answer
34 views

What means the numbers besides my default policy chain rules?

I am investigating a potential security issue in one of my system. My firewall tables currently look as, :INPUT ACCEPT [527:57388] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [189:35832] -A INPUT -p tcp -m ...
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66 views

Only allow http and SSH traffic

I ran the below. What I expected was to be able to browse websites without issues. No sites work and I have no idea what. When I executed iptables -P OUTPUT ACCEPT it works so I'm assuming I missed an ...
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0answers
71 views

IPTable rules for transparent outbound proxy

I've recently installed MITMProxy (similar to Squid) which I'm currently using to route outbound HTTP requests from my Ubuntu machine to another server (adding a header along the way). When I use ...
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0answers
163 views

Setting up a 802.11s mesh network for mobile devices to communicate with a wired server

I'm in the process of developing an android app that maintains a device's connectivity to a linux-based WiFi mesh network, and periodically sends status information (GPS, battery life, etc.) to a ...
4
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2answers
106 views

set connection limit via iptables

I want to limit the IP traffic of an application (AceStream Player). The problem is that I get disconnected, if too many IP connections are established. Does anyone know, how to use iptables to limit ...
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0answers
65 views

CentOS IPTABLES how to block requests from router

I have a CentOS machine that I use in private LAN for development and as file server. I did the following setting to allow httpd, GlassFish, Samba and SSH. Chain INPUT (policy ACCEPT 0 packets, 0 ...
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3answers
381 views

How to get all IPtables rules

I'm trying to see a list of all the rules in IPtables in a Debian 7 server. when I try: iptables -L -n I only get one rule (which I entered 5 minutes ago). I have many others, for port 80, mysql ...