Iptables is used to set up, maintain, and inspect the tables of IP packet filter rules in the Linux kernel.

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Can't initialize iptables table `filter': Table does not exist (do you need to insmod?)

I'm trying to open up port 1900 for UDP in order for the Echo to be able to discover the HA Bridge using the following command but I get errors. What is the best solution to fix this? ...
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Server iptables configuration

I have an application installed in the /usr/local/tomcat/fakebook directory. I want to allow any user to use the app and also all external user to use the app. I just want to allow connections to the ...
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Merging IPTABLES

In advance, thanks for all help! Hi. Got two ubuntu servers running fail2ban. I am currently trying to write a bash shell code to sync the iptables and / banned ips. So I got this rules from ...
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iptables port redirect in nat table but traffic still showing up in the filter table?

I asked a more specific question over on stack overflow a few days ago, but thought I would try and generalise it a bit here... In the nat table, does doing a port redirect in the prerouting chain ...
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28 views

DNAT redirecting to specifc port is not working

I want to redirect ssh by port using DNAT, and i do try to ssh it through the command > username@IP_ADDRESS:10003 and i got this message "ssh: Could not resolve hostname IP_ADDRESS:10003: Name or ...
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Still seeing connections from IP after blocking in fw

So I'm using iftop to monitor connections on my server, and I'm seeing this ip address 116.110.127.24 making constant connections on ssh port. (I'm not sure if this means 22 or my actual ssh port, it ...
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40 views

how can i kill all established connections before running iptables bash scrip

there is established connection from before running iptables bash script, and even this connection is blocked by iptables, but it keeps running because it is in established status, which according to ...
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35 views

meaning of -m in iptables

I use the following commands to turn my laptop into a router, that routes traffic from eth0 to wlan0 and vice versa. $ echo 1 > /proc/sys/net/ipv4/ip_forward $ sudo iptables -t nat -A ...
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192 views

Docker Transparent Squid Proxy

I am trying to run a squid3 transparent proxy in a docker image, on my laptop. Then on the same laptop I want to use the transparent proxy. The reason for the proxy is to abstract a corporate proxy ...
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85 views

Ubuntu as router; redirect traffic from 1 client (LAN) to VPN

I have a Ubuntu 14.04.03 router (iptables). Behind it there is a LAN with laptops, tablets, smart TVs, etc. I would like to use VPN on my TV, but there is no such option in the TVs software/firmware. ...
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27 views

the packet flow from a network interface to a local process? help!

I'm read Linux Iptables Pocket Reference. So I do not understand the figures presented. It says that packets travel through chains, and are presented to the rules one at a time and in order. Then ...
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Forwarding traffic with IPtables through a series of IDS

My goal is to run several Intrusion Detection Systems (IDS), these IDS sensors should be positioned in sequence, so the traffic will travel through the first IDS and will generate alerts of malicious ...
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62 views

Multiple connections per ip

I am running Ubuntu with a webserver (Nginx). I noticed that one IP has multiple connections opened. My server works all fine and there is no issue. I am just curious to know why there are many ...
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122 views

IPTables forward port to another ip:port but keeping original source ip

I have following iptables rules on gateway machine(192.168.0.1). I want to forward port 192.168.0.1:80 to 192.168.0.2:8080. But I need to maintain original source ip so that original server can get ...
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41 views

TCP IPTables Expert ubuntu 14.04

I started hosting my game-server on Ubuntu Linux 14.04 I am having an issues ، some enemies/bug abusers log in 2+ characters in the same second then they spam a certain spell/word that lags/stops my ...
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112 views

IPtables ubuntu 14.04 LTS

I am new to Linux, I used to use windows for years and this is my first time to use Linux "Ubuntu 14.04 LTS" I am hosting a game-server I was wondering if it is possible to make IPtables to kick if ...
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45 views

Connect two subnets so that they can see each other

I've got 3 machines (virtual) : A client, a server, and a destination. (All running ubuntu 14.04). The client and server are interconnected via a subnet, and have the ips 10.10.100.4 and 10.10.100.2 ...
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libiptc error on unbunt14.04

Am trying to work with iptables, using libiptc to manipulate the entries. Header looks something like this. I have iptables-dev installed on my machine. Am getting following error, but the same ...
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42 views

Forwarding UDP data between two local interfaces

I have server which has 4 eth ports: - eth0: 192.168.226.55 (Internet connection, default one default route) - eth1: 10.8.8.1 (local network) - eth2: 192.168.225.129 (Internet connection) - eth3: ...
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Internet Sharing/nat on 14.04lts vmware esx guest with usb internet

Situation: vmware esxi 5.1 Hosting a couple of Windows guests and a Ubuntu 12 file server that also is the local DHCP server and DNS server. Two NICs in the ESXI host to a small Wifi router which I ...
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489 views

Unable to connect to mongo on remote server

I have installed mongo on machine1(Ubuntu 14.04.3 LTS server) in my local network. I have also opened the port 27017 as mentioned in this guide using following commands: sudo iptables -A INPUT -p tcp ...
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Redirect port 3389 with iptables, to an IP network [closed]

I have on my network a linux server and it iptables firewall. On the same network, you have a Windows Server 2008 server. When I'm out of my network, I access the Server 2008 for RDP and this service ...
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35 views

ICMP Echo Request

This is my topology: My cloud is configured with eth0 adapter, connected to R1 port fa0/0. The R1 receives the address through DHCP Server, with it I can ping any public address.. R1#ping ...
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31 views

List active rules in Iptables

I would like to help me check the active rules in the iptables firewall. My S.O is Ubuntu Server 14.04.3 LTS Trusty.
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66 views

Does changing the hostname of 127.0.1.1 in /etc/hosts

I usually have this problem: lluis@biolinux[exercises] sudo gedit /etc/hosts sudo: unable to resolve host biolinux [sudo] password for lluis: Sudo is unable to resolve host(Because I changed my ...
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50 views

Would active connections cause this UFW Block?

I'm running ubuntu 14.04 as a gateway, routing is controlled by iptables. I'm getting a number of strange blocks in UFW which seem to effect established connections. Is there any way this block would ...
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146 views

Port forwarding between bridged interfaces

So I have a bunch of bridge interfaces bound with my main ethernet device (em1, blame HP). These serve various LXC containers I have running on my server and easily allows me to access them from other ...
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51 views

Iptables and Deny issue

I've configured iptables with FWBuilder, and for some reason there is a rule that is constantly dropped, and I don't know why, because all the address IP from and to 10.208.x.x (first server) and ...
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107 views

IP forwarding over OpenVPN (tun0) with external forwarded ports

I am trying to configure a very basic routing setup with Ubuntu Server 15.04. I have an internal interface p4p1 (IP 192.168.0.23) and a working OpenVPN connection using tun0. I want to forward all ...
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111 views

Server setup problems, am I missing something obvious?

So I've set up Ubuntu 14.04 as a LAMP. I've got it set up to do three things so far, all work fine over LAN. 1) Network printing. 2) Host a small webpage. 3) Act as a minecraft server. I've ran a ...
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72 views

How to setup VPN bridge between 2 networks

I have a small ubuntu box which I want to use to bridge 2 networks together over VPN. One network is in the 192.168.2.0/24 range. The other network is in the 192.168.93/24 range. Said ubuntu box is ...
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Forward port from 80 to 9000 not working

I'm trying to host an app on Ubuntu 14.04 and want to redirect traffic from 80 to 9000. sudo iptables -A INPUT -p tcp --dport 80 -j ACCEPT sudo iptables -A INPUT -p tcp --dport 9000 -j ACCEPT sudo ...
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66 views

Do I need iptables if only two ports are open to the public?

For a special task I have a root server running Linux Ubuntu 14.04. The server has a very minimalistic installation with ssh on a non-standard port and no root access. Basically the servers primary ...
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37 views

Unable to recieve UDP packets

I have a program which sends UDP packets to a specific port (eg: 53023) at localhost. I have written another program using Qt 4.8 which tries to receive the packets from this port at localhost. ...
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42 views

IP tables routing connected teamspeak clients

On a hosted ubuntu server VPS I host a teamspeak server. Is there anyway to use IPTables to force a connected client to join a different server by forwarding them to the IP? For example Teamspeak ...
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Why are NAT&Kernel IP Forwarding not working?

I'm trying to forward all traffic from tun0 to eth0,below is my interfaces: eth0 Link encap:Ethernet HWaddr 12:57:6e:6a:74:85 inet addr:172.31.32.133 Bcast:172.31.47.255 ...
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68 views

Do I need iptables or ufw if I have gufw?

On my Ubuntu computer I have Iptables,ufw and gufw installed on it but I am trying to figure out if I need to remove one so I did a experiment and removed iptables and I saw ufw and gufw was removed ...
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Why does Ubuntu comes with two firewalls by default?

I just realised Ubuntu comes with two firewalls by default iptables and ufw. But why? I mean running more than one software firewall on one computer can be insecure, that's what they say. I don't ...
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Tc filter show not working when classified with tc filter … basic command

We have configured the tc filters with the below rules. But when we try tc filter show dev eth1 its not displaying any of the rules. tc filter add dev eth1 parent 1:0 basic match 'meta(vlan mask ...
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32 views

External connections to website are blocked

I have a fresh install of Ubuntu server and am just trying to host a website on port 9999. My router is correctly forwarding the port to the hosting machine and I have set ufw to allow TCP on port ...
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34 views

Is there a tool to change both source and destination IP addresses at the same time?

I can't use IP tables, in a way that I know of, because of how/when it changes destination and source IP addresses. Destination IP is changed in pre-routing and source is changed in post-routing. The ...
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configure iptables to redirect traffic to a specific IP address

I have just began using iptables. I have a server with a public ip address (A.A.A.A) wich is hosting a Virtual Machine (B.B.B.B) on local network. I want to redirect all inbound traffic on the port ...
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153 views

Route traffic beetween LAN / WAN interface

we use an internal little server with a dhcpd service (pxe system). The server has two nic's: - LAN (PXE) - WAN (uplink of remaining company lan / network) WAN NIC is auto configured by DHCP server. ...
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63 views

how to remove squid to work as nat that already configured in ubuntu?

I'm running squid3 in my Ubuntu 14.04 and tried remote proxy use for study purposes . When I try remote access with another computer in the University LAN, I encounter empty cache log. So I have tried ...
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52 views

How to prevent net scan?

i have major issues with server provider due to net scan on local IP, sometimes on public ips too. how can i prevent this and/ or identify the user ?
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Find outr which IPs are from program and which IPs are from addons

I have a program (that legitimately calls authors) and plug-ins that also call authors (not so legitimately). I want to run the vanilla version of a program and collect IPs it is trying to connect. ...
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How to properly bridge NIC1 and NIC2 for MAAS with full access?

I have seen numerous postings about bridging, and using various other means and most of the posts ends with 'I got it'. I haven't got it. For one of my old posts I had used a router on one NIC that ...
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Resolve domain names to IP's based on physical adapter

System Configuration eth0 NIC to the LAN/WAN/Internet (working, don't want to mess with it) eth1 NIC eth2 NIC Objectives Assign a static IP to eth1 and eth2 and assign IPs (DHCP) on separate ...
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In the iptables i have a rule for ssh, why doesn't it work?

I have changed all the iptables chains to DROP, and made a rule to allow ssh from the computer (10.21.0.40, have hidden NAT, eth1) to Ubuntu Server (172.16.21.1, static ip, eth0), here is the rule: ...
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136 views

How to configure Ubuntu 14.04 server as router for WiFi?

I'm a student learning networking and working on my college project. We need provide the wifi to students We have one system with two Ethernet ports We have one TP-Link access point (Wifi moderm) ...