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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Terms for Low-cost low-power computer with lots of Ethernet ports [on hold]

I'm looking for a computer that's relatively cheap ($100?) and has lots (5? 10?) gigabit Ethernet ports (so no Raspberry Pi), isn't big (i.e. not a desktop computer with a bunch of PCIe cards), isn't ...
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Configuration of DMZ on LRT214

I want to learn more about network technology. Therefore I want to run a raspberry pi in the DMZ as a web server. What is working: Appache Server on the pi is working. When I use it in the LAN and ...
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1answer
26 views

Where is my firewall?

Using Linux Mint 17 and logged in as root... When I enter the command more /etc/sysconfig/iptables I get the error /etc/sysconfig/iptables: no such file or directory When I enter the command ...
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1answer
9 views

Linux gateway using double data on AT&T, is my iptables wrong?

I have cellular internet connection with AT&T. Everyone connects to the wifi access point that I have my Raspberry Pi connected to as DNS/DCHP/Gateway server. On my Pi I use dnsmasq to give each ...
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What's the difference between iptables “state” and “ctstate”?

I saw this iptables snippet in a different Super User answer: iptables -A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT ...
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1answer
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Hairpin NAT with dynamic WAN IP

I have a dynamic WAN IP so if it changes my iptables will no longer apply. Here is my working hairpin nat, where x.x.x.x is my WAN IP br0 - LAN eth1 - WAN -A PREROUTING -d x.x.x.x -p tcp --dport ...
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1answer
9 views

How might one version control Linux kernel firewall rules?

Our router is CentOS but we just use iptables to modify Linux kernel firewall rules. There is a script that's under version control which resets all the chains/rules, but in doing so drops all ...
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1answer
3k views

Allow access from outside network with dmz and iptables

I'm having a problem with my home network. So my setup is like this: In my Router (using Ubuntu desktop v11.04), I installed squid proxy as my transparent proxy. So I would like to use dyndns ...
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1answer
21 views

iptable rule to allow ftp connections between two networks

I have two machines, machine1 is configured with 192.168.1.0/24 network and machine2 with 10.10.0.0/24 network. I have dropped the communication between the two networks with iptables -P FORWARD ...
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1answer
570 views

Block all outgoing traffic for a User running Wine apps

Good day, I'm using a lot of WINE apps under Linux which work just fine, but one thing I am specifically looking for right now is to block their access to the internet (outgoing), with exception of ...
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rsyslogd: How to prevent logging in the /var/kern.log file and redirecting to another file?

I am trying to redirect iptables log to another file. Based upon my reading on the net, I did the following: In my iptables rule, I have rules like: iptables -A INPUT -s ... -j LOG --log-prefix ...
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1answer
9 views

Choose gateway regarding incomming node

I have a server behind 2 Internet Access. the ip are these: -Server : 192.168.0.1 -ISP 1 : 192.168.0.253 -ISP 2 : 192.168.0.254 I would like that packets coming from ISP 1 receive response using ...
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0answers
35 views

Logging LAN traffic with ebtables-iptables-ddwrt

Goal I am trying to log internal(eth0->eth0[via br0]) traffic to syslog on DD-WRT. Problem Bridged traffic is not seen by iptables. The same traffic is also not visible via ebtables. Things I ...
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1answer
54 views

Openwrt in bridge mode - ebtables kernel error

I have a setup at home as follow: DHCP clients -----> (wifi)(bridge) Openwrt -----> (eth)Main Router The device I'm using is TPlink MR3020 with Barrier Breaker and I tried to set up ...
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0answers
3 views

iptable flow packets to a VM

I want to create a VM to monitor the packet flow. My server is a Debian-based proxmox. How can I set up iptables so the VM sees all packets, but without changing anything else to the setup? Thanks in ...
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1answer
238 views

“iptables -P OUTPUT DROP” blocks DDWRT's web interface

When I do iptables -P OUTPUT DROP it blocks DDWRT's web interface. That is I am not able to access http://192.168.1.1 via Firefox. I put this rules before changing the chain policy to drop: ...
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Unable to install iptables [HELP]

Hello so I removed iptables for reasons I don't even know but when reinstalling i get this error Reading package lists... Done Building dependency tree Reading state information... Done Package ...
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Linux ip route / ip rule with fwmark and iptables -j MARK --set-mark

I just need to re-roure all user traffic directly to specified GW (different from the default one) bypass all VPN and other routing rules. Lets start it from scratch (reboot the system), no interface ...
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219 views

502 bad gateway after putting up firewall nginx

My server was working, then I added a firewall for a bunch of ports! And now I get the error: 502 Bad Gateway nginx/1.4.6 (Ubuntu) Nginx server { listen 80; server_name 45.79.80.140; ...
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0answers
4 views

iptables forward combined with bfifo doesnt work

I have 3 interfaces, 2 internal(wlan0,wlan01 )and 1 external (eth1) and i want to configure traffic from eth1 ,so i use iptables to send all outgoing traffic from the internal interfaces to eth1: So I ...
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18 views

How to use a local SOCKS server as a gateway?

I'm running a SOCKS proxy server (on an Ubuntu machine) which is used to bypass internet censorship. I'd like the devices in the same network (such as TVs etc), which don't support SOCKS, to use this ...
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11 views

write a raw packet to tun/tap

I am a newbie to the tun/tap and iptables. I am confused about some questions about the tun these days. Firstly, I create a tun interface named tun0 and set its ip address to 192.168.128.2/24. If I ...
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set tun interface to visit the internet

I have a tun interface named tun0(10.0.1.1),and a physical interface named eth1(10.110.136.76) on my computer. I want to use the tun0 to visit the internet. Firstly, I create and set the tun like ...
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iptables firewall only allows internet traffic if source port of 80 is allowed

I am configuring an iptables firewall, currently just to allow http and https traffic. It is working but under a particularly strange rule - I must allow incoming connections with a source port of ...
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1answer
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Allow http request over specific port in iptables

I'm running Kodi with a web service for the remote control. The web server is listening to port 11734, however opening that port (UDP and TCP) doesn't seem to work. Once I accept all incoming traffic ...
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assign IP to tinyproxy on OpenWrt

I have installed tinyproxy on OpenWrt and now I want to make rules for iptables that match traffic from tinyproxy. I want to mark this traffic with set-mark and route it to different routing table. My ...
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1answer
4k views

DD-WRT firewall rule configuration

I'm using DD-WRT on my linksys router. I want to limit each user on my network to 200 connections at any given time. Does anyone know the rules I enter the firewall in DD-WRT admit panel. I tried ...
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1answer
41 views

Cannot restart apache on Centos 7

I cannot restart HTTPD on Centos 7. When I try to run the command it shows this error below. How can I overcome this? -- -- Unit session-735.scope has begun starting up. Apr 12 15:33:01 ...
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1answer
34 views

iptables rule doesn't work for port 80

My VM has set some rules for access to a web server and a SSH. The server is running in the internal port 8080 en redirected using iptables to the port 80 with the command: iptables -t nat -A ...
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how many rules iptables or single chain support

I have multiple user (approx 800 users), I am developing IPTABLES firewall for MAC address based filtering. My Question is HOW MANY RULES CAN I ADD IN A SINGLE CHAIN AND HOW MANY RULES CAN HANDLE ...
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Automatically apply routes with /etc/network/interfaces

I have a usb-ethernet adapter. When it comes up, I am applying routes and rules to get the network working the way I want. I'm trying to add post-up directives to /etc/network/interfaces to apply the ...
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1answer
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ipset -j SET --add-set notwroking in cetos

I recently installed ipset rpm and kmod-ipset rpm for my Centos (Linux 2.6.18-194.11.3.el5 i686) and try to hands with help of some examples from internet, but when I try to ban user who tries to ...
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Iptables WiFi , blocking

I would like to block all Wi-Fi devices except one. I have two Wi-Fi routers and I am only allowing one in my IPTABLES rules to connect; but I am able to still connect to both. iptables -P INPUT ...
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fail2ban does not ban IP although there is one failed regex in table

I don't know why fail2ban not adding the bad ip into iptables rules. Here is my setup. /etc/fail2ban/filter.d/http-get-dos.conf [Definition] failregex = ^<HOST> -.*\"(GET|POST).* ignoreregex = ...
4
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2answers
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Using iptables to redirect ip address

I have the requirement on a Linux system where the Linux device is using RSYNC to sync data to another Linux machine. This is working fine at the moment, however I need to move one of the machines to ...
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Block Windows 10 P2P updates with a corporate firewall

I work for a small IT company that fix mostly Windows computers, and lately we have an huge issue with Windows 10 updates. When a new computer enters our network and starts downloading updates, it ...
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4answers
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IP forwarding from one interface to another on Debian 7

Background The Debian 7 that I run has the following interfaces wlan3 == Internet connection 85.5.48.64/24 wlan2 == act as an AP (hostapd) 192.168.5.1/24 I run the following settings on the ...
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1answer
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Cannot open port 8080

I'm running a VmWare with an application under JBoss starting up on port 8080. I'm able to access the app from outside the VM if the iptables are off. However, I must turn on iptables due to some ...
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1answer
20 views

Connected to hostapd hotspot but no Internet

I'm setting up a Gentoo Linux home router with following configuration: eth0: connected to WAN (managed by systemd-networkd) wlan0: access point for LAN (managed by hostapd) I use dnsmasq as DNS ...
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Block all inbound traffic except one IP using windows firewall rules

I have no problem doing this in linux. I just write an iptable to block all traffic and another one after to allow a specific IP. However it doesn't look to be that easy on Windows. I did the exact ...
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2answers
3k views

How can I port forward an LAN port to a WAN Ip with iptables?

Using iptables on my router (dd-wrt), I'd like to forward requests to the router on port 64738 from the LAN to an IP (192.168.10.14) on the WAN. This is the opposite of the norm (forwarding a request ...
0
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1answer
26 views

block most traffic on an expensive link

I'm running with two wan links. The new one is expensive, and I only want to use it for ssh. The new link is on eth1, 192.168.8.1. I am attempting to use ip tables to block all incoming and out ...
0
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1answer
33 views

Redirect secondary network interface traffic along with port forwarding to tun0 (OpenVPN) using iptables

I have a NAS server which I should do port forwarding for it in order to make its services accessible from internet. However my ISP is blocking ports, so I've managed to buy myself a cheap Ubuntu VPS ...
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1answer
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Iptables drop forward packets to specific host

I am having trouble isolating a specific host from others on my lan. What I am trying to do is only allow communication between 192.168.0.2. and 192.168.0.8 as well as not allow any other host to ...
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1answer
2k views

Synergy client won't connect, despite open port?

I want to use a Debian KDE desktop computer (network name bradbury) as the server, and a Windows 7 laptop (network name Clarke) as the client. I have used this setup before without problems, but then ...
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1answer
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SSH password login: iptables Log/Drops listsDST=18.9.2.13/18.7.33.13

Questions about general computing hardware and software are off-topic for Stack Overflow unless they directly involve tools used primarily for programming. You may be able to get help on Super User. ...
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1answer
59 views

Configuring CentOS 6.7 as a Squid proxy server: How may I solve this issue?

I'm using a PC running on CentOS 6.7 with 2 NIC's (eth0 & eth1) as a Squid Proxy server. eth0 (Red interface/ 192.168.0.2/24) is connected physically with the router (192.168.0.1/24) while the ...
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Linux routing traffic from wlan0 to localhost:port

I'm behind TGM proxy , connected via LAN on eth0 which goes to my laptop. Creating socks proxy tunneled with ssh via cntlm can bypass the proxy which is fine for my laptop. But I struggle to create a ...
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Sharing wlan0 internet to eth0

I would like to share my wireless Internet connection through a Raspberry Pi as follows: Raspberry Pi Internet --- (wlan0 --- eth0) --- Computer I have managed to setup the wireless ...
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Iptables redirect to localhost?

Suppose I have a network with a server routing all connections from inside the network to the Internet. How can I set up iptables so that instead of routing incoming connections to the Internet, it ...