iptables allow creation of rules to define packet filtering behavior.

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1answer
457 views

Routing through iptables

I have this vpn client that touches the routing table and then keeps watching it to exit if it gets touched. It is the kind of setup needed for an endpoint, such as a laptop. I want to use a small ...
3
votes
2answers
625 views

Need help with routing

I have set up a Ubuntu server, that I want to use as a router for my local office. The problem is, that I want to make 2 VPN connections, to remote branches, and then I want to route all traffic to ...
3
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2answers
787 views

iptables: rules for tftp server

I have a tftp server which listens on standard UDP port 69. I have added following rule to my iptables to block everything except UDP 69. -A INPUT -i eth0 -s 192.168.1.0/24 -p udp -m udp --dport 69 ...
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1answer
3k views

How can I redirect outbound traffic to port 80 using iptables locally?

I'm trying to locally redirect ports on my Ubuntu machine using iptables. Similar to transparent proxying. I want to catch anything trying to leave my system on port 80 and redirect it to a remote ...
3
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1answer
2k views

IPTables - Port to another ip & port (from the inside)

I currently have a NAS box running under port 80. To access the NAS from the outside, I mapped the port 8080 to port 80 on the NAS as follow: iptables -t nat -A PREROUTING -p tcp --dport 8080 -j DNAT ...
3
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1answer
415 views

tc on bridge port

I have a 4 port bridge: root@Linux-Switch:~# brctl show bridge name bridge id STP enabled interfaces br0 8000.000024cd2cb0 no eth0 eth1 ...
3
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2answers
361 views

iptables routing marked packets from router to PC and routing them back to router

I'm trying to do deep packet inspection on HTTP packets. The purpose of this is to collect HTTP payload data and then create some proxy/cache-independent reports. Following this, the idea is to ...
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1answer
1k views

tc don't see marked with -j MARK packets

Server has 2 network interfaces: eth1 with address 13.0.0.254/24 eth0 with address 172.20.203.4/24. It's routing traffic between this two networks. Task is to limit bandwidth between this two ...
3
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1answer
348 views

User associated with a socket

I use ss -p to see TCP sockets information. But process info are not printed for some sockets. Below: $ ss -p4 State Recv-Q Send-Q Local Address:Port Peer Address:Port ESTAB 0 0 ...
3
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1answer
370 views

1000 iptables entries on CentOS?

I just got a new dedicated server with CentOS and I'm trying to debug some network problems. In doing so, I found over one thousand iptables entries. Is this the default on a CentOS system? Is there ...
3
votes
1answer
2k views

Default mark for packets using iptables

I am trying to set up a QOS script on my Tomato-enabled WRT54G router. The script does the basics of what I need (make sure that a particular machine on my network has lower priority than anything ...
3
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1answer
98 views

What are the requierements to sniff UDP packets in a Wireless Ad-Hoc network?

In a wireless Ad-Hoc network, I have two computers which communicates in UDP together from 192.168.1.3 to 192.168.1.5 I have a third computer (192.168.1.6) which wants to listen to the packets which ...
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0answers
685 views

I opened a port with iptables but still doesnt work

I have a CentOS installation as a guest VM with VirtualBox. I have two ethernet interfaces, eth0 with NAT and DHCP, and eth1 with Host-only adaptor and static IP. I have oracle installed in this ...
3
votes
2answers
854 views

Port fowarding and load balancer in ubuntu server 12.04

I am looking to create a load balancing server. Essentially here is what I want to do: I have a public IP address, lets say 1.1.1.1 I have a second public IP address, lets say 2.2.2.2. I have a ...
3
votes
2answers
457 views

policy routing problem with load balanced ppp connections

This my setup using Debian 6.0.6. It's role is a proxy server and a load balancer using eight 3G modems. First and foremost: Whenever a ppp connection dials it takes over the default gateway which ...
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0answers
148 views

iCloud stuff stops working while connected to OpenVPN

I have a fairly simple OpenVPN setup on an OpenVZ VPS with Ubuntu 11.10. Client is the Viscosity client on Mac OS X 10.8.2, and after some testing, we can rule out the client as being part of the ...
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0answers
631 views

tunneling FON traffic via Tor

I would like to tunnel the traffic of my FON router through Tor. For that I added a second network card to a local server and connected the FON router to it. Then I set up a DHCP server and configured ...
3
votes
2answers
553 views

Open and redirect port

I'm trying to set up SNMP for a router so I can monitor it from an existing Nagios installation on an off-site server. I'm having trouble getting the router to respond to SNMP requests from the WAN, ...
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3answers
400 views

Undo iptables modification

I ran the following iptables commands to create a blacklist rule but used the wrong port: iptables -A INPUT -p tcp --dport 22 -m state --state NEW -m recent --set --name SSH iptables -A INPUT -p tcp ...
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6answers
383 views

Recommend a reading for learning Linux firewalls configuration for beginner?

I am using Linux at home and want to be able to configure firewall. I would like to understand what I am doing not just copy paste some rules from internet :).
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2answers
119 views

iptables multiple -d flags not allowed

I am trying to log all my outbound connections to a file using iptables. This is my rule: -A OUTPUT ! -o lo ! --destination 127.0.0.1 -m state --state NEW -j LOG --log-prefix "new_connection " ...
2
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1answer
822 views

iptables does not list rules i have created

I'm using this guide to set-up a shared internet connection between two PC's. At step 8 it says I should run the commands: iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE /etc/rc.d/iptables ...
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1answer
207 views

No internet even with iptables ACCEPT all

I was trying to setup the firewall settings, and probably did something wrong. I don't have internet now unless I stop iptables service I tried flushing,and accepting everything sudo iptables -F ...
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4answers
469 views

What does this iptables command do?

Does iptables -I INPUT -j ACCEPT open all ports?
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2answers
3k views

iptables log file

I have ubuntu and I want to know where can I find the log file of iptables? I find out /var/log/messages, but I am not sure this is a correct log file or not. And I also want to know when this log ...
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2answers
46 views

Are there ways to break into a machine if iptables drops all traffic?

Say I install Linux on an blank computer (no other OS, disk is formatted for installation), and I configure this in iptables: iptables -F iptables -P INPUT DROP iptables -P OUTPUT DROP iptables -P ...
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3answers
6k views

How can I redirect ports 80 and 443 to 8080 and 8443 with iptables?

I'm looking at the documentation for a Tomcat 6 webapp called DSpace, specifically in regardds to running Running DSpace on Standard Ports (80 for http:// and 443 for https://) I am trying to use ...
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votes
2answers
5k views

incoming ACCEPT all iptables rule still appearing

I'm following this guide here: http://isalazyadmin.net/2009/07/02/configuring-a-basic-firewall-for-debian-linux/ And I have the iptables listed shown, but my server still appears to be accepting all ...
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votes
1answer
2k views

Why does iptables still block my samba?

I'm currently fighting with iptables and samba. I read that samba needs ports 137-139 and 445 open on both tcp and udp. Here is the relevant part of my iptables config ... # forward valid incoming ...
2
votes
1answer
84 views

Bad argument `127.0.0.1' in iptables

-A OUTPUT --destination ! '127.0.0.1' -m state --state NEW -j LOG --log-prefix "new_connection " --log-level 7 gives me Bad argument `127.0.0.1' What am I doing wrong? I used this docs : ...
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votes
2answers
2k views

Remote SSH login not working

I have a PC behind a router with port forwarding setup Port 22 for SSH which works perfectly - I can login and everything. What I am trying to do is let this PC connect to a VPN and only allow ...
2
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1answer
2k views

iptables rule to allow access to internet

I made default policy of my machine- iptables -A INPUT -j REJECT #DROP ALL PACKETS TO INPUT CHANNEL INPUT channel has been blocked. Now I want to allow only some specific services like I should be ...
2
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1answer
83 views

Lost connectivity after iptables change

I attempted to add a couple web ports to iptables and in doing so lost the ability to resolve any external address. I have a working SSH session open and can get to the box easily if needed. Here's ...
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2answers
1k views

Debugging iptables using live packet views

Are there any CLI or GUI functions that I can use to monitor hits to iptables and watch as packets interact with iptables?
2
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2answers
382 views

Iptables port forwarding to qemu vm

Is it possible to create an IPtables rule that forwards all incoming traffic on port 80 on the host to port 80 of the qemu VM? Is such a scenario possible with qemu?
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votes
1answer
1k views

system wide SOCKS5 Proxy

I connect to my Server on the internet using ssh -D 3128 user@rootserver.com. If I am right I thereby open a SOCKS v5 Proxy to my Server. Using firefox and FoxyProxy I can now add this to my proxys ...
2
votes
1answer
26 views

Should IP tables rules affect a serial port on Linux

I'm trying to setup some iptables rules on my embedded Debian Linux system, using a serial console I entered this: root@ts7600-47aad3:~# iptables -F root@ts7600-47aad3:~# iptables -P INPUT DROP ...
2
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1answer
57 views

Port forwarding using iptables on Linux

I want to forward a local port to a remote port (8041) to a port (8042) on a remote machine (10.0.0.42). I can do this via ssh -L 10.0.0.41:8041:10.0.0.42:8042 user@localhost where 10.0.0.41 is ...
2
votes
1answer
151 views

How do I fix iptables in ChromeOS?

Using the shell in chrosh in ChromeOS I followed some (apparently terrible) advice to flush my IP tables. using the command sudo iptables -F I am now unable to connect to the internet at all. All ...
2
votes
1answer
48 views

How would I go about making this IPTABLE rule for every ip and not just one?

iptables -I PREROUTING -t nat -p udp -s 192.168.0.62 --dport 53 -j DNAT --to-destination 23.21.182.24 Instead of 192.168.0.62 I'd like to set that as a global rule, EVERY ip that needs dns should ...
2
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5answers
147 views

Difficulty setting up iptables

I'm very new to *nix operating systems, and I'm having some trouble which I believe is because of misconfiguration of the iptables firewall. My server has SSH running on port 22, and server software ...
2
votes
1answer
226 views

IPTables string match redirection

The issue: I am currently redirecting port 80 requests to another system on port 1000. This is done like so: iptables -t nat -A PREROUTING ! -s 172.20.1.2 -p tcp --dport 80 -j DNAT --to-destination ...
2
votes
1answer
581 views

iptables rules too restrictive; Drupal webserver cannot access repositories, ntp or even websites

This is a Drupal website running Ubuntu 12.04 LTS on Linode. Someone recently changed our iptables rules and a number of problems started. These include: Our Mollom spam protection is not working ...
2
votes
1answer
232 views

Can iptables be used to convert a single-homed host into a NAT server?

Given: I have a machine (HostA) with only one NIC which has Internet connectivity. I have another machine (HostB) with one NIC on the same switch. HostB is not configured for Internet access yet. ...
2
votes
1answer
162 views

Explanation of bandwidth management script calling tc

I have some scripts in Linux to manage internet bandwidth, but I do not understand what they do. What is the meaning of the following scripts: tc qdisc add dev $IF root handle 1: htb default 256 tc ...
2
votes
1answer
239 views

IPtables command shows libipt_random.so missing

When I run a command, it shows error. I searched on net, but no one give me the correct answer. Googling shows only wrong answers for this questions. So please help me to overcome this problem. ...
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votes
2answers
445 views

Is xinetd still the best method to let non root daemons listen on privileged ports?

When I need to use SNMP monitoring for java applications, there is the need to that application (usually ran as daemon user) to listen on snmp port. If there is no other alternative, of course I can ...
2
votes
1answer
2k views

Port Mirroring using iptables - copy all traffic among nginx on :80 and apache on :8080

I have nginx running on port 80 and apache running on port 8080 I want to transfer all the traffic to both nginx and apache asynchronously i.e the performance of one server wont be dependent on the ...
2
votes
1answer
7k views

Fedora 16 - Iptables installed, but no iptables service available

I'm trying to open ports on my fedora OS. In the past, this was as easy as adding an rule like -A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT I went to restart my iptables ...
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votes
1answer
847 views

What does this iptables entry mean?

iptables-save output: *filter :INPUT DROP [2929:172650] :FORWARD DROP [0:0] :OUTPUT ACCEPT [74596344:6265371965] These are the opening lines of the iptables-save command. What do the numbers in the ...