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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Iptables: allow specific ips on specific port

I am trying to allow a few IPs on port 80 and disallow all other from access port 80. Can someone suggest the iptables rules needed for this to occur?
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How do I configure DD-WRT to forward IPSec traffic to an internal server to support a road warrior configuration?

I use dd-wrt as my home router setup and that's been working fine. Now I wanted to figure out a way to be able to use my iPad to set up a IPSec tunnel to my home network while I'm on the road. PPTP ...
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1answer
991 views

How to route specific traffic through OpenVPN?

I'm running a server at home with rtorrent and apache2. I would like to route my rtorrent traffic via OpenVPN and since im kinda new to OpenVPN and iptables i would like to have a user friendly guide. ...
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1answer
985 views

Sharing transparently proxied Internet connection with PS3

I am trying to play a Japanese karaoke game on a PS3 but the latency is just horrendous and downloading songs takes forever. One recommendation I got was to turn my laptop into a SOCKS proxy by ...
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2k views

DNS resolving broken after installation of bind due to iptables

I successfully configured my web server (Apache, PHP etc.) and blocked the ports I don't need using iptables, which was working perfectly fine. Today, I installed BIND and configured it, which also ...
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121 views

Accessing ports remotely

I have a fedora server on a local network which I can access through VNC. I am trying to install a JIRA plugin called Activity timeline, these are both built using Java. When I log into VNC and ...
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628 views

Port 6667 can't be reached outside of localhost

I've got IRCD-Hybrid installed with the following listen config: /* listen {}: contain information about the ports ircd listens on (OLD P:) */ listen { /* port: the specific port to listen ...
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302 views

Load-balancing: response packets not routed - iptables

I have a problem with iptables. I'm trying to setup a load balancer between 2 uplinks. I can mark packets and connections, use ip rule to choose routing table (so changing the gateway). But, when I ...
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458 views

How to setup IPtables to allow capture network traffic from a virtualbox VM configured with NAT

I would like to have a VirtualBox virtual machine that can't get online. I want to be able to monitor all network traffic attempts from the Linux host. So, if the virtual machine attempts to make a ...
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283 views

Open up firewall automatically to anybody who has successfully connected via SSH

I have a server which runs a few services. However, for security reasons, I configured the server so that nothing, except for SSH, is accessible from outside. What I'd like to do instead, though, is ...
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2answers
5k views

How to route specific traffic through OpenVPN?

I'm running a server at home with rtorrent and apache2. I would like to route my rtorrent traffic via OpenVPN and since im kinda new to OpenVPN and iptables i would like to have a user friendly guide. ...
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1answer
1k views

Filter multicast from WAN to specified vlan

I'm using ebtables to filter multicast IPTV from my Wireless and Wired Lan. Right now its configured like this: Router ( DD WRT ) VLAN1 (PC Network) VLAN2 (IPTV) I am using this command: insmod ...
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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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What are the iptables rules to permit ntp?

My server's clock is wrong because the firewall doesn't permit ntp traffic. What are the iptables rules required to allow the ntp client to get out and back? Any suggestions how to implement those ...
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768 views

tc/netem and iptables: Delay traffic only from specified ip and port

I have a Ubuntu Router with 2 network interfaces. eth0 is the private network and eth1 is the internet. What I want is the following: All packages (mostly udp) comming from a specified private ip ...
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Filezilla not showing directory listing?

I had downloaded iptables from server to my windows desktop .I edited some lines for opening port (2195) .after download i added some line for enabling port using this link ...
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amule, Fedora 14, iptables

I need to set iptables rules for aMule, but I am not sure which one are the right ones. Googling around, I have seen something like: iptables -I INPUT -p tcp --dport 4662 -j ACCEPT iptables -I ...
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1answer
285 views

dd-wrt: Keep source ip after port forward

I just started using dd-wrt on my wndr3700, but now all my incomming connections to a server inside the network gets the same source ip as the router. How can I change this back so I get the real ...
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How to unblock jabber on TI ADSL router with iptables

I have old but reliable Texas Instruments ADSL router. Board AR7RD; BUILD=061005; VERSION=3.7.1 If that matters... One thing that bothers me is that it somehow blocking my jabber (Pidgin ...
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1answer
904 views

IPTables - unknown error 4294967295

I've moved an old Slackware 11 installation from a physical PC to a virtualized in ESXi. Everything seems to work fine except for one rule in iptables, namely the row: iptables -t filter -I INPUT -m ...
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2k views

Access Apache server running in Fedora guest VirtualBox from host

I have trouble accessing Apache server from host. I’ve Fedora 15 VM VirtualBox installed on Windows 7. Within this VM I have Apache server running and working fine within the guest. Not sure what ...
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How to negate a range in iptables?

I've seen people use the exclamation mark (!) in multiple examples, but when I try to use it I get an error. The rule I'm trying: -A OUTPUT -m owner --gid-owner 1006 -d ! 192.168.1.0/24 -j DROP The ...
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How to “shut off” all networking on Linux from bash?

I'd like to write a bash/shell script that "turns off" the machine's ability to communicate over it's network card, effectively shutting down all networking. From the command line: # To turn all ...
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What is command to look list of redirect rules, iptables

im using command like this : iptables -t nat -A PREROUTING -p tcp -d 192.168.1.118 --dport 4080 -j DNAT --to-destination 192.168.1.118:4088 My question what is command to look all rules in the ...
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pfctl port forwarding in Mac osx?

-A PREROUTING -s 10.0.10.0/24 -p tcp -m tcp --dport 80 -j REDIRECT --to-ports 8080 -A PREROUTING -s 10.0.10.0/24 -p tcp -m tcp --dport 443 -j REDIRECT --to-ports 8080 -A POSTROUTING -s 10.0.10.0/24 -o ...
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107 views

why does this iptable rule work at a specific position in the chain

I'm running OpenWrt on my router, which allows me to run applications such as apache and emule. I installed emule but I keep getting lowid, indicating that my port is misconfigured. I was able to ...
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No output returned when curl ing any URL in Red Hat 6 but the same url works in lynx browser

I am trying to install some packages in Python using easy install. But i get a 'Download Error' for any package i try to install. So i tried to test if internet is accessible at all from the machine ...
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OSX: Mimic Ubuntu IP Masquerading via iptables with ipfw

Good day, I am attempting to replicate a setup I have between a router and an Ubuntu PC, and have the same setup working on my MacBook (10.6, Snow Leopard). First, I have a router that has a USB ...
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1answer
396 views

How to resolve conflict in iptable rules

In Ubuntu 12.04 and above there are no iptable rules defined by default. I added the following rule and it works fine:(Update) iptables -A INPUT -p tcp -j QUEUE -m string --string xyz --algo bm ...
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695 views

MIxing RFC1918 NATed and public IP addresses using IPTABLES

I wish to host a SIP server and DNS at the end of an ADSL2 connection. My current network sits behind an iptables firewall which runs on a Linux box with two Ethernet interfaces, the WAN interface ...
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1:1 NAT IP address using iptables

Suppose I have 2 internal networks: 1.1.1.0/24 and 1.1.2.0/24 I would like to NAT a specific IP address from one network to the other, in which the new address would be obtained via DHCP. For ...
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115 views

IPTables Allowing Access without Rules

I'm sure this is mostly my misunderstanding of how iptables works, but I've set up some rules... -A INPUT -p tcp --dport 22 -m state --state NEW,ESTABLISHED -j ACCEPT -A OUTPUT -p tcp --sport 22 -m ...
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9k views

need to route the traffic through a specific network card

I have two network cards and they both have a different network. I need the outgoing connections to go only through a specific network card. Any help ? Update: I ran a route -n command and got this ...
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2answers
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iptables block everything except http

I'm trying to configure my iptables to block any network traffic except HTTP: iptables -P INPUT DROP #set policy of INPUT to DROP iptables -P OUTPUT DROP #set policy of OUTPUT to DROP iptables -A ...
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1answer
287 views

Why does Firefox need a loopback connection?

I was playing around with firewalls and iptables. When I blocked any traffic except HTTP and DNS I was able to establish a connection to google.com via wget google.com. But I wasn't able to open ...
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327 views

IP forwarding with iptables

Suppose there are hosts A and B. A is allowed SSH access to B based on its IP address. Consider now another host C. C does not have access to B, but if we could route its traffic through A, then C ...
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CentOS 6 - iptables preventing web access via port 80

I'm setting up a new web server with CentOS 6.2 and am not able to connect via the web. Everything looks set up correctly in httpd.conf and Apache is running, so I'm assuming it's an iptables issue. ...
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381 views

IP tables gateway

I am trying to make an iptables gateway. I ordered 3 dedicated server from my hosting company all with dual nics. One server has been given all the ip addresses and is connected directly to the ...
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1answer
575 views

Different routing rules for a particular user using firewall mark and ip rule

Running Ubuntu 12.10 on amd64. I'm trying to set up different routing rules for a particular user. I understand that the right way to do this is to create a firewall rule that marks the packets for ...
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1answer
1k views

Pinging an external server through OpenVPN tunnel doesn’t work

I have an OpenVPN server and a client, and I want to use this tunnel to access not only 10.0.8.0/24 but the whole internet. So far, pinging the server from the client through the tun0 interface works, ...
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296 views

CSF Unresolved issue

I began receiving service failures for CSF/LFD once the limit was reached in iptables preventing the service from working properly. I flushed all iptables rules, and redid by rules using CIDR rather ...
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543 views

Routing table on Linux not respected

I have a very specific problem, building a Linux VPN endpoint (with external VPN Gateway), which should route certain networks over the tunnel, others via default gateway. The Linux VPN should do a ...
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1answer
66 views

Is there an alternative of TrivialProxy for linux?

Does anyone knows an alternative software of TrivialProxy for linux? iptables is not enough because I need a GUI. Thanks in advance.
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How to blacklist IPs on Windows 7?

I'm trying to find something similar to iptables in Linux for Windows. I've tried using Windows firewall as well as editing the host file to block specific IPs, but had no success. I've also tried ...
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1answer
429 views

Rate limiting traffic between specific hosts (based on their MAC) using iptables

I have setup a simple isolated network consist of following Linux based machines (simplified example): Node1<---->Router<---->Node2 Router's eth0 is connected with Node1's eth0. Router's eth1 is ...
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Will increasing number of rules in iptables slow down my internet

How much impact will the rules have on speed, if we are using match to queue the packets.
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776 views

Difference default setting on iptables between CentOS 6.3 and Ubuntu 12.04

I would like to ask in ubuntu 12.04, there is no firewall settings by default? iptables -L Chain INPUT (policy ACCEPT) target prot opt source destination Chain FORWARD ...
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1answer
618 views

Reasons why ports below 1024 cannot be opened

I'm root on a machine I don't know how it was configured. I try to open SSHD on another port than 22 but it does not work. I changed the /etc/ssh/sshd_config file and added a new Port line extra to ...
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Is there a decent diagram of packet flow for a modern era (2.6+) iptables setup?

I'm currently trying to debug a particularly hairy set of DNAT based iptables rules (the UDP reply never makes it back to the original requester) and I'm struggling to visualise the packet flow ...
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1answer
4k views

Reverse Proxy for TCP (RDP, VPN, etc) and HTTP

I have a domain that points to my ISP assigned IP though a CNAME (cname goes to my noip address incase my ISP decides to change the IP), I would like to route different subdomains to various IP:PORT ...