iptables allow creation of rules to define packet filtering behavior.

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Are iptables global or user ip specific?

For example for my web server port I have the following rule: iptables -A INPUT -p tcp --dport 80 -m state --state NEW -m limit --limit 1/m --limit-burst 15 -j ACCEPT #If you spam concurrently for 15 ...
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15 views

iptables presale me to ssh access or calling methods remotely

I have a linux openwrt unit. At its start, I can not make a ssh access if I do iptables -F. If I use iptables -L -n -v, I find several rules that are automatically inserted and it prevents me from ...
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692 views

How to block telnet using iptables command

I am trying to block telnet on my server but I have failed to do so. I have added following firewall rules in INPUT chain of filter table for the same. INPUT CHAIN(filter table): <some other ...
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2answers
144 views

iptables configuration - ssh connection only from a remote network

I'm trying to configure Iptables of a server in order to permit SSH incoming connections only from a certain network. by the way this is the rule chain : # Drop anything we aren't explicitly ...
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698 views

ip rule not acting on fwmark

I'm trying to use iptables to load balance web traffic over multiple DSL lines by marking the packets and routing based on the mark. I'm working with CentOS 6.6, Kernel 2.6.32-504.16.2.el6.x86_64, ...
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334 views

AWS Outbound ACL Rules impact on incoming ssh connections

I am making a bastion ssh server on CentOS 7 in an AWS EC2 instance. When I use the following rules in its ACL, I am able to connect to the server just fine: Inbound Rules Allow traffic on port 22 ...
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95 views

What ports will an ssh daemon use outbound?

I am making a bastion ssh server. When I use the following rules in its ip tables, I am able to connect to the server just fine: Inbound Rules Allow traffic on port 22 from my client's IP Block all ...
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431 views

Audit on changes to the running iptables configuration

I'm aware of how to audit for changes to the /etc/sysconfig/iptables file in CentOS/RHEL 6 and earlier, but how do I audit for changes made only to the running configuration?
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181 views

IPTABLES to allow ssh, ftp, pop, etc from one static IP address with HTTP/SSL open to public

This is my setting in /etc/sysconfig/iptables: #start of my iptables # Generated by iptables-save v1.2.11 on Wed May 27 00:31:22 2015 *mangle :PREROUTING ACCEPT [130933577:29488298585] :INPUT ...
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71 views

Modification needs to be done in iptables in case of a bridge between two interfaces is implemented

I have a machine with 2 NICs; eth0 and eth1. Each NIC has an assigned IP address and the traffic between them is controlled using the below script. #!/bin/bash SAT_RECV="192.168.200.0/16" NQ=9 ...
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1answer
92 views

Using a VPN for certain applications via a network namespace

I am trying to use a network namespace for VPN-specific traffic, using this guide: https://schnouki.net/posts/2014/12/12/openvpn-for-a-single-application-on-linux/ on Debian. Everything works with ...
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114 views

Why is my laptop being blocked from connecting to a PPTP VPN server?

I have a fairly simple network at home Internet --> Modem --> Linux Router --> Switch --> Laptop The problem: There is a PPTP VPN server at work that I need to connect to from home. I configured my ...
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1answer
75 views

Blocking or forwarding packets as access point

I set up my Pi 2 as a wifi access point following this tutorial. I'd like to implement a rudimentary QoS, according to the DSCP field in every packet's header. That means, blocking packets using low ...
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5answers
30k views

Viewing all iptables rules

I just wanted to ask if there's a way to view iptables rules in a bit more detail I recently added masquerade to a range of ips iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j MASQUERADE ...
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1answer
106 views

FTP passive mode, fails

Hi I am trying to setup iptables to allow FTP. When I connect with FTP, i get the following message in my filezilla. Status: Connected Status: Retrieving directory listing... Command: PWD ...
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122 views

to allow certain ips and block all other connections on AMAZON EC2 ubuntu 12.04

How do I allow certain IPs and block all other connection in iptables on AMAZON EC2?
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2answers
243 views

How can I allow SSH and SMTP only using IPTables?

I've got a raspberry pi set up to send me periodic emails. As it's connected to the internet 24/7, I need IPTables set up properly. I want to allow incoming SSH and allow emails to send out on port ...
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148 views

Unable to setup iptables for ftp passive mode [duplicate]

I tried the following rules to allow FTP: # The following two rules allow the inbound FTP connection iptables -A INPUT -p tcp --sport 21 -m state --state ESTABLISHED -j ACCEPT iptables -A OUTPUT -p ...
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1answer
1k views

How to redirect all HTTP request to a local web server

How to redirect all HTTP request to a local web server, supposing we don't have an internet connections Exemple Web server with @IP 192.168.1.1, running apache Client with @IP 192.168.1.X making a ...
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1answer
107 views

Interfaces, IPTables, Connections, Local Connection - Confused :/

I configured my iptables today and ran into some questions i could not resolve yet. So it would be nice, if someone could verify or answer the following to clarify: Each interface can be configured ...
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1answer
82 views

Linux IPTables - Ignore Range of IPAddresses

I am currently modifying some of my IPtables rules on a public server and have run into a bit of a dilemma. The goal is to do the following: Rate limit the amount of SSH connections that can be made ...
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35 views

equivalent of iptables rule in ip6tables

I m newbie in the iptables. I have the following iptables rules in the source code of a project iptables -t mangle -I PREROUTING ! -i br0 -p TCP --dport 45 -j MARK --set-mark 0x1000 iptables -t nat ...
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1answer
154 views

Route a port through a network interface

I'm using OpenVPN on Ubuntu Server to connect to my VPN. That network interface is tun0. All traffic currently goes through the VPN. I'd like to exclude traffic that goes over a specific port, and ...
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271 views

Block all tor traffic from my server

I'm trying to prevent all traffic from Tor exit nodes from hitting my website. I've searched and have attempted a few of the solutions, this is what I've done. I curled the ...
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2answers
254 views

Routing Configuration sending some traffic over VPN

I have a DD-WRT router with an OpenVPN service configured. I'd like to send only certain source IP's over the vpn connection. I believe my current routing table (as seen with netstat -rn) sends all ...
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3answers
126 views

How does the iptables work with IPv6?

I would like to set up a firewall on Linux Debian for IPv6. It is important to use iptables for me. I have tried to change the ipv4 folder to ipv6. How can I set up iptables for IPv6?
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251 views

Forward traffic coming into dummy interface on to another interface(?)

Can I forward traffic coming into a dummy interface on to another interface? Or is it not a real interface at all even? Chain FORWARD (policy ACCEPT 0 packets, 0 bytes) pkts bytes target prot ...
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1answer
81 views

Unexpected netstat output in DNAT conditions

So, here I have a basic setup with SOCKS5 proxy listening on, oh, say 8123 I redirect TCP to the proxy via iptables From iptables perspective everything looks peachy, iptables -t nat -v -L shows ...
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1answer
124 views

package from IP arrives at certain port => open portrange to IP for x seconds

I have been toiling with an issue on iptables: I am trying to make a portrange open to a specific IP for x seconds/minutes as a result of a single packet being sent to a specific port. Not exactly ...
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1answer
261 views

Change iptables log format

Is it possible to change the log format of iptables ? I want to add the ssh_client in the log. I have already made an iptables rule for outgoing ssh iptables -I OUTPUT -p tcp --dport 22 -j LOG ...
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288 views

ubuntu lts and cgroup support in iptables [closed]

I don't understand why Ubuntu community built iptables without cgroup support and what I don't understand if community didn't make it? Maybe Ubuntu use another some way (iptables without cgroup etc)? ...
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435 views

How to match properly against an IP set of type 'hash:ip,port'?

My current setup is that I have a server with several IPv4 addresses. Let's ignore the IPv6 part for now, as the symptoms are identical there. In the firewall rules I'd like to match against HTTP ...
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1answer
41 views

Access to webapp from a different machine

So i have three virtual machines (virtual box). One is the router/firewall. It's running snort + snortsam . This machines runs a webapp in tomcat From this machine I'm trynig to access the webapp i ...
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1answer
94 views

Allow ftp out through iptables

I have been having difficulty allowing ftp through iptables. Right now my ftp looks like this. Chain INPUT (policy DROP) target prot opt source destination ACCEPT tcp ...
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191 views

Valid iptables Firewall on DD-WRT to access Internet on a Virtual Access Point

Device: Linksys WRT54G v5.1 Firmware: DD-WRT v24-sp2 (07/22/09) micro - build 12548M NEWD Eko I use this router as an AP with 2 SSIDs (Private wl0 + Guest wl0.1) and I connect it to a switch ...
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1answer
79 views

What is blocking: Firewall and tcpwrapper?

Is it possible to find whether the firewall (iptables) or tcpwrapper is blocking a connection without accessing the remote server? (Maybe with tcpdump?)
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472 views

Port forwarding with iptables and PIA VPN for single user

I've gotten a Private Internet Access VPN setup on a Mythbuntu 14.04 machine and I am at wits end trying to get port forwarding working with rTorrent (and ruTorrent). My setup is rTorrent running ...
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3k views

Fedora 21 Port Forwarding with firewalld (firewall-cmd); how does it REALLY work? Or, does it?

Fedora's ability to forward ports using the apparently "native" networking software, firewalld, appears to continue to be broken beyond credulity. Please note that it hasn't really worked since at ...
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122 views

Linux - iptables - get YouTube streaming bytes usage

How do I get bytes usage using iptables for a particular IP, including YouTube streaming videos? Currently, I am using the following IP tables rules to get data usage by IP address: sudo iptables -I ...
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137 views

IPtables errors

I am working on a project. I am trying to write iptables rules to control network traffic. I have written some rules. When I try to apply them to the boxes that I am working on I either get locked ...
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1answer
126 views

linux nat different rules

eth0 (192.168.1.0/24) --> wan eth2 (192.168.10.0/24) --> lan0 I use these rules to enable NAT on my linux gateway: iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE iptables -A FORWARD -i ...
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475 views

How can I redirect internet traffic from local to proxy server with ip tables (DEBIAN 6)

So i made topology as shown in figure. Router have 3 interfaces like this: eth0 to internet side (with ip 192.168.1.10/24 gateway 192.168.1.254/24). eth1 to server-PC side (with ip ...
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98 views

Route wireless LAN through OpenVPN

I am trying to set up my home server to act as an OpenVPN gateway so I can connect to my VPN from any device without installing special software of them. My server is running Ubuntu 14.04. The host ...
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0answers
103 views

How to route vpn traffic over hostapd-raspberry pi

I have a raspberry pi running hostapd and I am able to connect my laptop as a wifi client to the raspberry bi wifi router. The problem is with the vpn traffic, I cant connect to my office vpn with ...
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1answer
31 views

iptables drop policy

Audit my rules I'm ask if I really need of two INPUT policy: iptables -P INPUT ACCEPT iptables -F iptables -A INPUT -i lo -j ACCEPT iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT ...
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50 views

iptables not getting saved ? centos

I am trying to save the iptables, when I run command #service iptables save it says [ok] but when I again open the iptables the rules get revert to default. Can anyone help me to understand this ...
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180 views

mount times out with iptables --policy OUTPUT DROP

I previously ACCEPTed all output traffic by default. Recently changed the policy to DENY output by default, only opening ports needed for server/application functionality. When I tried to mount a ...
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579 views

CentOS as home network router: IPTables Port Forwarding failure

I have currently set up a home server with a CentOS 6.6 installation on it. The server has two NIC interfaces which I'm using it as my router and DHCP server. Here's a diagram showing the network ...
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163 views

DDOS defence with iptables

I have server with Debian 6 with a many games servers and sadly, I'm getting ddosed. So, there is my ask for help. I want make solid firewall, where my server will safe.
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1answer
133 views

On a router, what decides if a packet should be forwarded or directed into the router itself?

I'm trying to learn how packet routing works on a linux-based router (OpenWRT in my case) a bit better for setting up a few projects/just-learning. Referencing the below chart, I'll break this into ...