iptables allow creation of rules to define packet filtering behavior.

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Redirect traffic through the server

My task is to redirect traffic (port range) through the server. Here is the schema: Why NAT is not appropriate here: If NAT is set to "Tunnel Server", then all users will be assigned the same IP. ...
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130 views

Config iptables ssh over VPN

How can I define a rule that only allows ssh via VPN in iptables? My iptable Rule is following: #!/bin/sh IPT="/sbin/iptables" $IPT --flush $IPT --delete-chain $IPT -P INPUT DROP $IPT -P FORWARD DROP ...
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580 views

Switching between Network Interfaces

I am trying to write script to switch between two interfaces on a Linux machine, wlan0 and eth0. My primary reference is: http://askubuntu.com/questions/338100/forwarding-traffic-between-2-interfaces ...
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68 views

Nat with saving real client IP

I have this schema: Client -> NAT server -> Game server On NAT server I have the following rules: iptables -A FORWARD -d $MC_IP -p tcp --dport 25550:25580 -j ACCEPT iptables -t nat -A PREROUTING -d $...
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1answer
2k views

iptables allow only ssh and vpn traffic

I have dedicated server with ubuntu 14.10 installed. The server should connect to an openvpn server and the traffic should only go through the vpn, except for SSH traffic. My idea is to realize it ...
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277 views

Get real IP after OpenVPN tunneling

I try to route traffic from one Server to another using OpenVPN. In the end users should only connect to the forwarding machine. It basically works using this iptables rules: iptables -t nat -A ...
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1answer
4k views

how to block only certain outgoing ip connection with iptables

(Centos 5.5) to block xxx.xxx.xxx.xxx: # iptables -A OUTPUT -j DROP -d xxx.xxx.xxx.xxx then verify by: # iptables -L OUTPUT --line-numbers Chain OUTPUT (policy DROP) num target prot opt ...
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506 views

NAT External IP to local server using iptables

I have a adsl connection with static IP (lets say 1.1.1.1). My debian firewall connects Internet with ppp and IP is assigned to firewall directly; ppp0 Link encap:Point-to-Point Protocol inet addr:1....
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68 views

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: [root@localhost ~]# firewall-cmd --get-active-zones work sources: 192.168.122.1 public interfaces: ens3 [...
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2answers
561 views

Why do iptables drop / log even if the appropriate packet should be accepted?

I'm setting up a server running Debian Jessie with some applications like iptables firewall, fail2ban, openvpn, apache, ... The iptables firewall is configured in the way, that it logs every packet ...
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500 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 0.0.0.0/...
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1answer
562 views

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 ...
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1answer
402 views

IPTables Firewall/Router/Gateway needing to block outbound traffic from users

I have multiple ethX interfaces. eth0 is connected to the internet. eth1 is connected to a trusted network. eth2 is connected to a network I need to impose usage rules. What I'd like to do is ...
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1answer
3k views

forward packets from one interface to another interface using iptables

I have an embeded system with 2 interfaces e0 and m0, whose ips are 10.0.0.20 and 192.168.0.20, respectively. Incoming packets into e0 have an ip of 10.0.0.10 and should be forwarded to m0 interface ...
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1answer
668 views

PPTP Through IPTables

If this has already been answered, I apologize, I could not find an answer to this during my searching. I am new at Linux/Unix and I have recently implemented a Raspberry Pi firewall/gateway on my ...
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169 views

iptables - How to remove connection tracking

I'm using this command for redirect all web traffic (http) into my local web server iptables -t nat -I PREROUTING -p tcp --dport 80 -j DNAT --to 192.168.11.100 Then i test, access a website and got ...
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iptables - Redirect web traffic to LAN Server

I have a webserver which is running on ip address 192.168.11.100 How can i use iptables to redirect all web traffic (http and https) to my webserver on LAN? After that i want to add except list mac ...
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1answer
396 views

How can I set up the ULOG target with iptables and MySQL

I'm running CentOS 6.6 32bit as a firewall box using iptables. I want to be able to use the ULOG target to store dropped packets in a MySQL database for statistical analysis. After much Googling I ...
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1k views

iptables - Redirect except list MAC Address

I'm using iptables on my router to redirect all web traffic to my page. But i don't know how to except my mac address list. I did command like this: iptables -t nat -A PREROUTING -m mac ! --mac-...
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0answers
477 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 ...
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160 views

Redirect all ARP traffic from eth0 to eth1

I would like to redirect ARP traffic, but I'm struggling with arptables and ebtables. I have 2 interfaces: eth0 10.10.10.25 eth1 10.10.10.20 Both in 10.10.10.0/24 I want to redirect the ARP ...
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30 views

how to block my phone from the vps?

My android phone wlan mac is x1:x2:x3:x4:x5:X6 I want to block the phone to logon in the vps. here is the iptable command: iptables -A INPUT -m mac --mac-source x1:x2:x3:x4:x5:X6 -j DROP I found ...
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1k 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, ...
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1answer
3k views

Port Forward :80 and :8080 to Two Different Servers

On a CentOS 6 server with an IP address of 172.16.1.10, how can I configure iptables to route traffic destined for 172.16.1.10:80 to 192.168.1.10:80, and traffic destined for 172.16.1.10:8080 to 192....
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1answer
369 views

Stateful user-space firewall for Linux

Is there any stateful user-space firewall for Linux? I'm looking for a firewall that doesn't rely on anything in Linux kernel (like iptables/netfilter) and works with raw packets.
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342 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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1answer
2k views

Java Client Connection Refused by Linux Server

I have a Java server and client, which is a simple server that prints a message when the client communicates with it. It works perfectly fine when the client and server are on the same machine. When I ...
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0answers
190 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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181 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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1answer
141 views

Redirect traffic destined for IP and port

I have a program that wants to connect to 1.2.3.4 on port 5678, but it can't because the port is blocked on our network. However, I do have an SSH tunnel set up that redirects localhost:5678 to 1.2.3....
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161 views

What does this iptables rule mean?

Reading this article on how to configure OpenVPN, I see the following paragraph: Raspbian has a firewall to protect your Raspberry Pi from unknown and unexpected Internet sources. We still want ...
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2answers
2k views

Forwarding a Localhost:Port to an ExternalIP:NewPort

We have got an application running on our linux server. From that application, when we try and access localhost(127.0.0.1):localport, it should be forwarded to an external IP. Users will only try and ...
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1answer
217 views

iptables, differentiate ports based on hostname

Is there a way, using iptables, to ACCEPT traffic from HOSTNAME1, HOSTNAME2, HOSTNAME3 to port 22 and FORWARD traffic from everyone else to a different port and make the rule persistent? HOSTNAME1/2/...
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218 views

How to unmask an IP with iptables?

Is there a way to unmask an IP using iptables? I know to mask all-in-one is following by: iptables -t nat -A -POSTROUTING -j MASQUERADE
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1answer
434 views

iptables: route packets to example.com via public proxy

I want to access certain websites via a public proxy and I can't seem to get it right using iptables. Let's say I want to access example.com having ip address 1.2.3.4 via a public proxy at 5.6.7.8:...
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3answers
487 views

How to make Raspberry Pi to receive an IP from a router and also pass another IP to another device?

I know that I could achieve the desired result with an Ethernet switch, but I'm curious if I can get this with some cheaper solution. The idea is as follows: Rapsberry Pi has two Ethernet ports - ...
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1answer
599 views

How to use both syn proxy and connlimit rules with iptables?

I want to write both syn proxy and connlimit rules. I want to send packets to syn proxy first because of performance issue. Here is rule sample. I use bridge interfaces but I dont think it is ...
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0answers
101 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 ...
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188 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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1answer
2k views

iptables configuration for Transparent squid proxy

I have to setup a transparent squid proxy server using iptables and squid. Following is the scenario: [INTERNAL NETWORK] -> [Main Switch] -> [Proxy Server] -> [Firewall] -> [EXTERNAL ...
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1answer
133 views

Using IPTables to block all connections but still be able to backup vServer

my vServer / webserver (OS: Debian squeeze) got hacked and compromised. Therefore I want to use rules in IPTable to block all input and output connections except ssh. Afterwards I want to backup at ...
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3answers
483 views

Unknown cause for redirect on 80 port

I have an Ubuntu 14.04 server with Apache 2.4.7 running there, hosting one site on 80 port. Today I discovered that every request to 80 port redirects to another website with response: HTTP/1.1 301 ...
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242 views

DNAT forwarding for FTP: No route to host

I have a single public IP for multiple VM, i need forward multiple ports for FTP service, i write these lines: iptables -t nat -A PREROUTING -i eth0 -p tcp -m tcp --dport 20:21 -j DNAT --to-...
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365 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 (10.1....
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1answer
73 views

Virtulisation IPTables Rules

I haven't been able to find a solution this as of yet. I'm not very experienced in IPTables so any support you can provide will be appreciated. I have a server with a few VMs on there. The main node ...
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1answer
888 views

Iptables rules for remote mysql server

I have a local mysql database on a centos server which causes a lot of load because there are a lot of queries made towards it. I want it hosted on its own server but i dont want every single ...
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1answer
128 views

What considerations would I need when configuring iptables?

Synopsis I am looking at learning more about Server Administration. I have been running my own web server for a few years although many things were set-up by my friend and now I wish to learn more ...
3
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1answer
426 views

How to combine connlimit with IP sets?

connlimit lets me limit the number of connections per client/service. How would I go about to combine such a rule with the IP sets available in more recent versions of the Linux kernel and netfilter?
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1answer
152 views

Connection lost to VPS While using iptables by default policy as DROP for INPUT, OUTPUT, FORWARD

I'am using iptables in many server's but now stuck with this issue while using default Policy as DROP. Here is my rules which i have used in VPS, Tried many time's everything seems fine but VPS ...
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How to carry a string over from one chain to another in iptables?

Here's what I'd like to do. In my rule file (which I use with iptables-restore) I have (with limits removed): -4 -A LOGDROP -j LOG --log-prefix "ipt:4:drop " -6 -A LOGDROP -j LOG --log-prefix "ipt:6:...