iptables allow creation of rules to define packet filtering behavior.

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3
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59 views

iptables: using “conntrack” and “recent” modules to block unsolicited packets

When I only allow RELATED and ESTABLISHED packets, and DROP everything else, my firewall rules work perfectly and I have no problems: ### VARIANT A -A INPUT -i wlan0 -m conntrack --ctstate ...
3
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68 views

Is iptables able to filter off UNREPLIED connections?

I am a using dd-wrt router and trying to get some per-user metrics, I was wondering about filtering only ESTABLISHED connections or include NEW and RELATED, I have read a lot about this last two, but ...
3
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89 views

Route VPN traffic through different proxies

I want to setup VPN server and route (based on my routing algorithm) all traffic through different proxy servers. Let's say I have one host, with many users, connected to my VPN. I want to route all ...
3
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0answers
222 views

iptables rule no actions on scapy packets

I wrote this rule to change all udp destination IP addresses to 8.8.8.8 when dport is 53: iptables -t nat -A OUTPUT -p udp -m udp --dport 53 -j DNAT --to-destination 8.8.8.8 The rule worked when ...
3
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0answers
82 views

Packets do not cross IP tables Postrouting when originating from an external IP

I'm trying to reflect traffic from the internet to an internal device that I only want to have local access. I have a host in my DMZ that I'm trying to DNAT traffic to this internal device, and SNAT ...
3
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187 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 ...
3
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711 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 ...
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39 views
+50

Iptables can't forward from/to internal LAN with proxmox

I have an host with proxmox with single public ip and some virtual machine installed whit webservers and multiple doimains, the first VM is a proxy with haproxy that forward the request to other VM ...
2
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39 views

Routing traffic for specific user to specific interface

I have a Linux box with these interfaces: eth0 Link encap:Ethernet HWaddr 14:da:e9:ef:75:7d inet addr:176.9.85.182 Bcast:176.9.85.191 Mask:255.255.255.224 tun0 Link encap:UNSPEC ...
2
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44 views

restrict IP traffic between VLAN sub-interfaces

I have a router/firewall-PC with two VLAN sub-interfaces eth2.100 and eth2.200: I would like to allow communication between networks 192.168.100.0/24 and 192.168.300.0/24(PC3 network). In addition, ...
2
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15 views

Dropping packets before mangle POSTROUTING

In iptables on Linux 3.10, why do packets which have been DROPed by the FORWARD chain of the standard table still appear in the POSTROUTING chain of the mangle table? -- I'm trying to use the standard ...
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42 views

debugging iptables when tunneling one VPN through another

I seek to tunnel one SSL VPN (F5, running on my debian laptop==client) through another (OpenVPN, running on a debian linode==server), but lose all client networking (including, e.g., ping) after the ...
2
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0answers
34 views

Strange cron behaviour

I have a script that reads a list of IPs from a file, compares with the existing ones in a chain, and adds recently added IPs in the file into that chain. Running the script manually (e.g., ./script) ...
2
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0answers
40 views

VPN tunnel to two services on two servers?

I've got 2 CentOS 6.5 servers, each running one service: server A: 10.140.54.1/27 running service MySQL port 3306 server B: 10.140.54.2/27 running service httpd port 443 Server B's httpd service ...
2
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120 views

how to open up socks/SSH on different network interfaces?

iptables -A PREROUTING -i usb0 -t mangle -p tcp --dport 8080 -j MARK --set-mark 1 iptables -L Chain INPUT (policy ACCEPT) target prot opt source destination Chain ...
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450 views

How do I route bittorrent through a second interface?

I've managed to configure openvpn on my DD-WRT router such that the tunnel is up and working, but that it doesn't mess with routes at all (the default configuration wants all traffic to go through ...
2
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163 views

iptables rule to transfer UDP through a SSH tunnel

The problem I have two programs that runs on two distant computers and communicate through a specific protocol. All I know is that this protocol only communicates through UDP and uses the ports 1101 ...
2
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0answers
27 views

Extra overhead in MASQUERADE target

There's a part in iptables manual concerning SNAT and MASQUERADE targets. I know the key difference between the two, but I don't fully get the following sentence: It is still possible to use the ...
2
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48 views

How can I configure iptables for per application setup?

I am working on a project where we are building lots of micro-services. Each service is neatly packaged as an RPM. Ideally I'd like for us to have iptables enabled on all of our machines and it would ...
2
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0answers
196 views

iptables hangs at applying rules

I have a set of rules that are supposed to give me the most protection before things like fail2ban and other things are added to the mix. The issue is that although everything checks out in the test, ...
2
votes
0answers
72 views

Transparent Proxy

I am setting up attempting to set up a transparent proxy on CentOS using Squid. So far I have managed to filter the content and get it working perfectly. The only issue I am having is getting a form ...
2
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0answers
78 views

Defining IPv6 chains in ip6tables-restore/iptables-restore files, is it possible?

The format for the files generated by iptables-save/ip6tables-save and loadable through iptables-restore/ip6tables-restore stipulates that one can prepend -4 or -6 respectively so as to maintain the ...
2
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566 views

Corosync & Pacemaker IPTables Rules

When using Corosync with two rings via multi-cast addresses 226.94.1.1 (Port 5405) & 226.94.1.2 (Port 5406) what iptables rules are required to allow two nodes to communicate optimally without ...
2
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0answers
477 views

Route all HTTP traffic through polipo

I've set up polipo on my machine to listen to the default port 8123. To test it, I set the in-memory cache to a ridiculously high 2 GB and downloaded a 50 MB file using wget utilizing the proxy. ...
2
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273 views

iptables REDIRECT in combination with matching on interface vs. IP address

I've successfully set up Tor for transparent proxying using iptables (ie, all outgoing traffic is sent through Tor without the application's knowledge). In doing so, I discovered both an odd problem ...
2
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279 views

SNAT problem in iptables

I am trying to reroute traffic from specific devices in my house over openvpn. For this, I've created an OpenVPN tunnel between my house wifi router and my server. Here is my setup: Wifi router's ...
2
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0answers
217 views

IPTables dropping UDP packet stream

I have a configuration where UDP packets containing encapsulated DNS data are sent to a KVM instance for processing. The KVM instance sits behind an IPtables firewall which is also doing NAT. The ...
2
votes
0answers
333 views

Iptables and Port Scanning and Recent module

I'm trying to write an adaptive firewall using iptables, and am not clear on how the recent module is working. For example, see http://blog.zioup.org/2008/iptables_recent/ Snippet from my iptables: ...
2
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370 views

TPROXY for redirecting UDP on arbitrary ports

I want to intercept all UDP traffic leaving tap1. And possibly reply to e.g. DNS-requests. To accomplish this I wrote some python code listening to localhost and use iptables with a rule-set like ...
2
votes
0answers
271 views

Port Forwarding Between 2 Internet Machines

Here's my scenario: Setup There are 3 machines: A: on the internet : has ip (a.a.a.a), has port pa open B: my server / gateway : has ip (b.b.b.b), has port pb open C: on the internet : has ip ...
2
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579 views

Iptables - modprobe: FATAL - Fail2ban random restarts

I have been running fail2ban on my server for a while without any problems but have recently seen fail2ban restart randomly. After some looking in my logs I noticed that the restarts occur when ever ...
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17 views
+50

Why is traffic matching the public zone instead of the desired zone

Trying to self-train on firewalld I set up apache and configured the zones as follows: My expected result is that traffic from the hypervisor would match the "work" zone and since http isn't ...
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0answers
36 views

iptables: No chain/target/match by that name

I'm trying to configure iptables to get Redsocks working {purpose is to get system wide socks proxy} #!/bin/bash # Create new chain iptables -t nat -N REDSOCKS iptables -t nat -A REDSOCKS -d ...
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0answers
14 views

redirect all ARP traffic from eth0 to eth1

I would like tredirect ARP traffic. Im struggling with arptables and ebtables but i cant see the light :) I have 2 interfaces : eth0 10.10.10.25 eth1 10.10.10.20 Both in 10.10.10.0/24 I want to ...
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45 views

Limit transfer speed rate by Iptables Rules

I have D-Link Router DSL-2730U that support busybox OS and iptables version 1.4.0 I managed successfully to block the host for being connect to the internet using the following command block by ip ...
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29 views

Shorewall on router keeps blocking apt-get update on virtual guest

I have a dual-IP LXC server with several unprivileged containers configured for three users. Each user has his own bridge: lxcbr0, lxcbr1 and lxcbr2. For efficiency, the host runs apt-cacher-ng. Each ...
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49 views

iptables / VLAN: interface names

I have just started working with VLANs. My memory was VLAN interface names are the interface name plus dot plus the VLAN ID. And that is what vconfig offers. After some (successful) manual tests I ...
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0answers
24 views

netfilter rules to forward all traffic to a local website by default, and making exceptions to that rule by macaddr

This is for raspbian acting as a gateway. computers -> [eth1] raspberry pi (dhcp) [eth0] -> modem/router -> internet I made an ip forwarding rule which redirects all traffic coming from eth1 ...
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0answers
91 views

Redirecting all non-local traffic from specific ip to external proxy

I currently have a squid proxy running on an external server (outside the LAN, with a public IP). I would like to route all non-local traffic from a specific device through it. That is, any requests ...
1
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0answers
55 views

Internet sharing disappears when either eth0 or wlan0 gets disconnected

I just got a RasPi B+ and I'm looking to replace the Windows PC that's doing the routing job. What I'm trying to do with the Pi is making it share the connection (wlan0) with another wifi router (via ...
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0answers
67 views

route gateway proxy traffic through different interface with identical upstream gateways

My question is similar to the below with a small caveat not answered by any of these threads: Output traffic on different interfaces based on destination port ...
1
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0answers
22 views

Initial iptable rule and knockd operation in vps

Today I launched a vps with Debian 7 x64 and started playing around with it. I installed xampp as well as knock daemon to get my hands dirty. So, all I wanted to do was to actually block all requests ...
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0answers
65 views

I Need Find A Mac Address from a client connected to my Teamspeak

I have a dedicated server and from it I am running a teamspeak 3 server. In teamspeak server there is a client who need to be banned. I have banned him from teamspeak but if you change your windows ...
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29 views

iptables rules to issue with tftp

My requirement is to add iptables rules in such a to allow tftp traffic(as a client) and drop everything else. And in fact using the iptc library programmatically using C code. To start with I tried ...
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69 views

Using a VPN client as a VPN gateway

I would like host 1 to use host 2 as a gateway to the remote host 3. I have scoured the web looking for a solution, but it doesn't seem to work for me. VPN client software is ike (shrewSoft VPN) is ...
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43 views

Set user-wide network proxy settings on Ubuntu (without restart)

Is there any reliable way to set proxy settings user-wide for all traffic on Ubuntu? As far I'm using {http|https|ftp}_proxy variables in /home/$USER/.bashrc which is nice but there's some issues: ...
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87 views

iptables: can't open tcp port

I'm running a Raspberry PI B+: Linux pi 3.12.28+ #709 PREEMPT Mon Sep 8 15:28:00 BST 2014 armv6l GNU/Linux The Raspberry is connect via lan (dhcp. ip: 192.168.78.29) to the local network. I'm trying ...
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0answers
51 views

Transparent proxy to other IP of thousand ports

I was bought a service that only allow a IP, the IP that i say, only one, but I need use this from more IP's. I think that I can install in this computer a system to do a transparent proxy for ...
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21 views

iptables packet header capture and compare

We are using multicast program to listen up multicast data from our provider, there are couple cases where the multicast having issue: 1. their server hang, hence no multicast data received from our ...
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0answers
72 views

How to route pakets from an aliased interface towards a gateway?

I'm having trouble setting up the following: Router IP: 192.168.1.1 PC Eth0 - 192.168.1.104 Eth0:1 - 10.0.0.1 (must be an alias) Besides ip_forward enabled, what should I add to iptables rules, so ...