Iptables is a module that provides the Linux operating system functions of firewall, NAT and logging of data traveling over a computer network.

learn more… | top users | synonyms

1
vote
1answer
215 views

Adding a custom SSH port to Ubuntu 12.04 LTS through UFW

I am trying to configure a Ubuntu 12.04 based VPS and I have changed my ssh port from 22 to 803 and everything worked fine. After this I've installed UFW and now I can't login using SSH. Before I ...
0
votes
1answer
113 views

CentOS 6 service iptables panic

me and my friend were doing some firewall configs and in the meanwhile he thought it was a good idea to type "service iptables panic". Now we cannot put the firewall back on the original state ...
1
vote
0answers
213 views

iptables load balancing for TLS with request routing on the same connection

I am trying to set up iptables rules for TLS connection. I have three internal IP in my machine and I route requests coming on public IP at port 443 to each of these internal IP in RR. -A PREROUTING ...
0
votes
0answers
61 views

Let everything except SSH/VPN use a VPN-Connection, but keep SSH working

Given the latest revelations about the size of Internet surveillance, I decided to route all my traffic trough an out of country VPN. I set the OpenVPN client up on my Router (Asus RT-N56U using ...
1
vote
1answer
145 views

Disable SSH remote tunneling

I need to restrict SSH tunnel functions. Users should not be allowed to create remote tunnels but only tunnels to localhost. I tried to setup the whole thing in the SSH configuration but I can only ...
1
vote
0answers
84 views

nc connection refused even on loopback

I'm working on an embedded linux system, which appears to be networked correctly and is running ssh (dropbear) and rpcbind. I'm setting up a server application on it, and every single thing I try ...
2
votes
2answers
902 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 ...
2
votes
1answer
2k views

How to allow FORWARDing with firewalld on a Fedora 19 router

I've just installed Fedora 19 and I'm using firewalld instead of iptables, but I'm having difficulty interpretting the new terminology. I have 2 NICs. One is specificed ZONE="internal" and the other ...
0
votes
1answer
90 views

iptables as a proxy

I'm not sure how to start better so i'll be straight. I have to travel to a foreign country, but i need access to a server that is local to my hometown network. I have a DD-WRT router with only my PC ...
0
votes
2answers
106 views

Server can't be accessed

I have a server I rent from OVH and I rebooted it and now I can't connect to it, OVH responded with "The server has started (login is requested on the screen) but inaccessible by the network (not ...
0
votes
0answers
1k views

Using iptables to give an LXC container a routable IP

I'm using Docker to manage LXC containers. At the moment Docker configures the underlying LXC container with host-only routing and then uses iptables/DNAT to punch holes into the container, making it ...
0
votes
2answers
59 views

port based nating with iptables

on eth0 port we have public ip and eth1 we have ip 10.31.0.1 which provides dhcp and squid service.Port 8080,53,67,80,443 is open.Now for an application we have to open 1521,8443 port so that it can ...
0
votes
0answers
43 views

Libnetfilter code not working on a virtual machine

I am writing a code using libnetfilter_queue. For those who don't know, this library provides me the capability of accessing network packets in the userland. In the userland, I am doing certain ...
0
votes
0answers
86 views

Multiple eth0 addresses (aliases) and TCP source address

My eth0 card has several aliases from the same subnet (Load Balancing software) and eth0 IP is set as leading to default gateway on this host. I have an application that listens only on eth0:5 on ...
0
votes
0answers
41 views

Sniffing data on uClinux local loopback

I am looking for a way to monitor/sniff local loopback traffic inside a uClinux embedded device. I have several processes that communicate via the local loopback and want to capture this traffic on an ...
0
votes
0answers
234 views

Can't telnet: TCP connection doesn't get established

I am having issues with telnet from a machine. TCP connection is not getting established. SYN gets sent out and SYN_ACK comes back but not sure why the ACK is not getting sent back. I am guessing ...
1
vote
2answers
907 views

CentOS 6.4 and alternate SSH port not working

I've got a CentOS 6.4 machine and would like to change the default SSH port, and followed these instructions: CentOS Wiki After making those changes (including the "semanage port -a -t ssh_port_t -p ...
0
votes
0answers
866 views

Forwarding RDP connections with iptables

I have a workstation that runs Windows 7 as the host, and Ubuntu Server 12.04 in VMware on a bridged network. Both have their own static public IP address. However, I only have one hostname to work ...
0
votes
0answers
146 views

Linux Traffic Control of internet downlink with router as a client

I'd like to shape my internet downlink bandwidth in a bit peculiar way. My linux box at home acts as a router and a torrent client (and other downloads), making my router a router and client inside my ...
0
votes
1answer
229 views

Iptables output with options unknown

I have been learning and studying up on iptables and port forwarding. There is a sample iptables output I can't decipher. It has the options --dir, --pol, and -m. Although I am familiar with -m it ...
0
votes
0answers
303 views

Port Forwarding to internal device without default gateway using iptables

I need to access externally (via Internet) one device in internal network which has no default gateway configured. Just IP and Mask. The standard iptable rule to accomplish the first part of this ...
0
votes
0answers
119 views

Public IP is not accessible

I have a VPS, after a DDos attack, the service provider disabled my server until the attack finished. After recovering from the DDos, the main IP is not accessible at all! I don't know where to look. ...
0
votes
1answer
836 views

Fedora's firewalld vs iptables

I am on Fedora 19. Is my understanding correct that as long as firewalld is up and running (and properly configured using firewall-config) the contents of the /etc/sysconfig/iptables has no meaning? ...
2
votes
1answer
1k views

Bandwidth limit by Port on iptables

What iptables function would i write to bandwidth limit all traffic on port 566 to 2KB/s? Im confused exactly of how to do this.
2
votes
0answers
158 views

Limit bandwidth on HTTP downloads based on file size

Is there a way to limit lets say in iptables or any proxy solution/software if a user is downloading a filesize that is greater than lets say 20MB it will limit his entire download at 2KB/s? ...
3
votes
1answer
456 views

Seting up IPTables to forward multiple GoPro cameras

I have an interesting problem that involves multiple GoPro cameras. Basically, I need to have the ability to communicate with multiple GoPro cameras via a single network. The challenge is that the ...
0
votes
0answers
225 views

Accessing my own public IP (WAN) via PPPOE internally

I have my own machine along private ip (LAN ip) 192.168.0.1 and public ip (WAN ip) IP 123.45.67.89 through PPPOE connection. So I wanted to access my own Apache server through my own public ip ...
0
votes
1answer
777 views

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 ...
2
votes
2answers
327 views

Force certain applications to use VPN

For a few days now, I've been trying to force only certain applications to use a VPN. I've thus far found it pretty simple to either force all applications to use it, or no applications to use it. ...
1
vote
1answer
347 views

Internet access to host behind firewall using ssh tunnel

My goal is to give host behind firewall access to the internet. Below you can find brief description of network [internet] <-> [proxy] <-> [A] <-> (firewall) <-> [B] [A] - ...
1
vote
3answers
3k views

Source Based Policy Routing & NAT (DNAT/SNAT) aka Multi WANs on CentOS 5

Originally posted at Unix and Linux but nobody was able to answer it, so m migrating the question here: My question is regarding Source Based Policy Routing on CentOS 5 with 2 WANs plus a LAN (NAT) ...
1
vote
2answers
108 views

DNS set correctly but website unreachable

I have the (sub)domain elo.bernardinuscollege.nl, which has a DNS A record that points to 54.225.118.87, which is correct (checked it with telnet, which indeed returns the right IP). For some reason ...
0
votes
1answer
946 views

How to do port forwarding/redirecting on Debian?

I have two questions. Question 1: My debian machine has interface eth3 with ip 192.168.57.28. If someone tries to connect to 192.168.57.28:1234 how do I redirect the request to another machine: ...
1
vote
3answers
379 views

Setting up two ADSL lines for home/business use

As a follow-up to this question which is still unresolved. I have two ADSL routers with different providers connected to different phone lines to the internet. As shown in the diagram. These routers ...
4
votes
2answers
16k views

need iptables rule to accept all incoming traffic

For my test environment i want to accept all incoming traffic, can someone please give me the iptable rule to be added. My current iptables -L -n output looks like this Chain INPUT (policy ...
0
votes
0answers
67 views

Restricting users to Internet only (no LAN) on router (RT-N56U and DGL-4300)

I've been working on this for the past 6 hours and have made no progress. The setup looks like this: |Internet|---|Router1|---|Router2|---|LAN1| | | ...
0
votes
1answer
418 views

Unable to ping my VirtualBox VM

I've installed a VirtualBox VM from http://virtualboximages.com/CentOS+6.4+x86_64+LAMP+Server+VirualBox+VDI+Virtual+Computer. My VM has access to internet, and I can ping the host. I've set a static ...
0
votes
1answer
2k views

Redirect incoming https to local ip with iptables

I have a router with 1 network interface (eth0, public ip) and an alias for eth0:0, local ip 192.168.1.1. I want to redirect all incoming https (443) traffic to another server. I tried it with ...
1
vote
1answer
356 views

Multiple IP addresses through the same interface and iptables

System Admin is not my strong point. My situation is we have 1 website that has 4 domains. The website itself serves different templates/content depending on which domain is used, simulating 4 ...
2
votes
2answers
1k views

what does “-m tcp” mean in this iptables rule?

Firewall configuration written by system-config-firewall -A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
1
vote
1answer
1k views

Forward connections on 0.0.0.0:80 to 127.0.0.1:9091

I'm trying to set up a tor-relay. In order to allow tor to present a static web page explaining what it is I want the server to listen on port 80 and 443. In order to allow tor to use ...
1
vote
1answer
153 views

Can't reach web server from local virtual network

I have installed a couple of virtual machines. Some uder Windows, some under Fedora Linux. On one of the Fedora machined I've installed Apache web server. I have setup server name in httpd.conf to ...
0
votes
0answers
101 views

Wireless printer connected to Raspberry Pi running iptables

My Setup: I have a Raspberry Pi set up as an access point using hostapd and dnsmasq I've got an Android tablet connected and a Samsung wireless printer. I have iptables running on the Raspberry ...
0
votes
1answer
476 views

iptables MASQUERADE and SNAT together

Good people, I have a network having the following setup eth0 10.216.11.41 internet facing eth1 192.168.0.4 internal network interacting with other machines within the internal network. Id like ...
0
votes
1answer
94 views

IPTABLES to block sites on browser

I am trying to block a specific IP address from being accessed using the browser on my system. I added a simple rule as below iptables -A OUTPUT -d <IP> -j DROP The site gets blocked in the ...
0
votes
0answers
208 views

iptables not working on DDWRT firewall

I have write a firewall rules for DDWRT router but I didn't work. What I needed is, I would like to set all my wireless user, once it reach daily quota which is 200mb it will disconnected from the ...
0
votes
0answers
1k views

Can't connect to mysql by telnet 127.0.0.1

I can't telnet MySQL on my localhost. MySQL is up and running and works fine with Apache-SSL/PHP/MySQL server but I can't connect by telnet: telnet 127.0.0.1 3306 Trying 127.0.0.1... telnet: Unable ...
0
votes
0answers
361 views

block specific request to a url with iptables via fwbuilder

I want to drop an http request to a specific url if it is made more than 20 times in 20 minutes. I guess it is something like following (please correct me if I'm wrong): iptables -I INPUT -p tcp ...
0
votes
0answers
28 views

Modify rule when service crashes

I have a iptables rule in PREROUTING that redirects all incoming to a specific port, where a service consumes the data. Is there a dynamic way to determine if the service has crashed and remove the ...
1
vote
1answer
405 views

OpenVPN + Squid or another way of blocking advertisements/websites?

I have a personal VPN that I use on my tablet for public wifi protection. Adblock+ is limited on android in that you need to set up a proxy for it to work, and this isn't ideal. Before I started ...