Iptables is a module that provides the Linux operating system functions of firewall, NAT and logging of data traveling over a computer network.

learn more… | top users | synonyms

0
votes
1answer
27 views

Set block time with iptables

I have the following rules in ufw, for iptables: -A ufw-user-input -p tcp --dport 80 -m state --state NEW -m recent --set -A ufw-user-input -p tcp --dport 80 -m state --state NEW -m recent --update ...
0
votes
1answer
55 views

Will an inbound iptables rule in ddwrt on port 443 break https?

I want to run a vnc repeater service on my home ddwrt router. Due to the possibility of friends/family asking for support in unknown network environments, I'd like the host-repeater application to run ...
0
votes
1answer
59 views

No internet through OpenVPN

I am having trouble with my OpenVPN setup. I have a Linode box with an OpenVPN server installed on it and I managed to get Tunnelblick to establish a vpn connection from my mac. I followed this guide ...
2
votes
1answer
472 views

IPTables module ip_tables not found for root

We got a custom build Linux distribution from a vendor, which is not shipped with iptables enabled. root@xxxx:~# iptables -L modprobe: FATAL: Module ip_tables not found. iptables v1.4.21: can't ...
0
votes
0answers
56 views

Iptables redirection to squid proxy server

I'm trying to setup filtering through a squid proxy however I'm having trouble getting my router to send all traffic to the proxy using iptables. I've currently got it setup such that there is the ...
0
votes
0answers
30 views

Iptables intercepting traffic

I have 3 servers on the network (Server 1: 10.0.0.1, Proxy server: 10.0.0.2, Server 3: 10.0.0.3) and I would like to intercept the traffic going through the proxy server from Server 1 to Server 3. ...
0
votes
0answers
41 views

Access lxc container services from other lxc containers via host

I've got a laptop with Ubuntu 14 Desktop. The laptop has WLAN connection to my LAN and is managed by network manager. Of cause, the laptop a nic (eth0), too, but it is not connected. I use this laptop ...
0
votes
1answer
21 views

iptables - I'm losing control over the box by adding new rule to the config

My set up is the following: Internet uplink (200Mbit) DMZ (1GB ethernet) Internal network (1gb internet) Log interface My gateway is serving around 600 clients with 1400 iptables rules in ...
0
votes
2answers
110 views

Is it possible to force DNS for certain devices with iptables?

I'm trying to use iptables to force DNS for certain devices (Shibby Tomato on Asus RT-N66U). I haven't found anything online describing such a configuration. The closest I could find was this: # For ...
0
votes
1answer
94 views

Configure iptables firewall to allow DHCP, DNS, HTTP, SMTP, FTP, IMAP, POP, and Squid ports – deny all other services.

Configure iptables firewall to allow DHCP, DNS, HTTP, SMTP, FTP, IMAP, POP, and Squid ports – deny all other services. 1 pc for router ( place firewall) 1 pc for server ( place web,dhcp,ftp,etc)
0
votes
1answer
384 views

iptables not starting on CentOS 6

I am running CentOS release 6.5 (Final) and cannot figure out why my iptables is not starting. I may have executed some other command to permanently prevent the start up of iptables; I do not ...
0
votes
1answer
199 views

Difference between iptables default policy to `DROP` and inserting a seperate policy in input chain to DROP all connections

I'm trying to DROP all incoming connections to my server, except from particular networks. At the same time I want to keep all outgoing connections from my server to external network (any network over ...
2
votes
1answer
56 views

Iptables redirecting

I have set up a Personal hotspot using Hostapd. But this hotspot is not connected to the internet but I do have Apache installed on it. What I am trying to achieve is to redirect all the clients (that ...
0
votes
1answer
18 views

iproute2: How do i connect one machine to the internet via another

I have the following setup: A > 169.254.8.125/16 <--(ad-hoc)--> 169.254.9.109/16 < B > 192.168.178.21/24 <--(wifi)--> 192.168.178.1/24 < AP/router > internet I want to connect A to the ...
0
votes
4answers
69 views

IPtables keeps resetting rules and blocking almost everything

Every time I reset IPtables, the rules keep coming back in about 10 minutes, blocking everything besides port 22 and 80. When I do a "iptables-save", I see this I can't find out where it's coming ...
-1
votes
1answer
81 views

cant run php FastCGI in arch

I have a PhpStorm IDE in Manjaro(Arch base Linux). I install php and php-fpm from repository and config PhpStorm with php. PhpStorm can know php and that version. but when i run my php code in ...
0
votes
1answer
24 views

iptables and router port forwarding

I need to access my home computer remotely using ssh. I have port forwarding set up on my router to send me to the appropriate computer on the local network. I have it working but viewing my home ...
0
votes
0answers
46 views

getting request into lxc-guest via host firewall but no answer (openvpn inside lxc)

my goal is to set up openvpn inside an lxc-container and i came close but it could not manage to get an answer out of the host. The Setup Host: public ip: 88.88.88.88 (on eth0) LXC-Gateway: ...
0
votes
0answers
24 views

IP rule table look up does not seem to work

I have a sytem with three network interfaces. Below is the configuration that I'm trying to set up. wlan0 (its actually an WiFi AP interface) - other devices connects via this interface. net1 - ...
1
vote
1answer
110 views

Expose a Reverse SSH Tunnel on the Remote server

I set up a Reverse SSH tunnel from my home computer to my work server: ssh -f -N -R 19999:localhost:22 remoteuser@server To connect to my home computer I have to first log in to the server and then ...
1
vote
1answer
36 views

confusing INPUT,OUTPUT iptables rules

Following is my iptables rules in Ubuntu. ╰─$ sudo iptables -S -P INPUT ACCEPT -P FORWARD DROP -P OUTPUT ACCEPT -A INPUT -i lo -j ACCEPT -A INPUT -p tcp -m tcp --dport 22 -j ACCEPT -A ...
0
votes
2answers
72 views

How to block sites like facebook.com, google.com etc. for different users

I use iptables for other sites as: iptables -A OUTPUT -o EXTERNAL_IF -m owner --uid-owner USERNAME -d DESTINATION_WEB -j REJECT It works for most sites except ones having a large range of IPs. What ...
0
votes
0answers
42 views

Meaning of Bridge-Check in iptables flowchart

In the famous iptables flow-chart what does bridge-check exactly stands for ? I couldn't find any documentation. The only clue I found was while scanning the MikroTik RouterOS documentation ( ...
1
vote
1answer
89 views

Most secure way to have IPtables auto-loaded using Debian / Linux

I'd like to know the safest way to load iptables using Debian. Of course, I can use a script that uses iptables-restore : #!/bin/sh iptables-restore < /etc/firewall.conf but : 1) where is the ...
0
votes
0answers
26 views

Is it possible to know a user logged in on Ubuntu instantly?

In fact, I am trying to restrict access to some websites for different users. I asked the question: Restrict access to some websites for different users. The given answer is ok; but as the owner ...
0
votes
0answers
61 views

Output port redirect with firewalld?

I'm used to iptables and I can't find a way to do this with firewalld. I need to redirect the output traffic of one port back inside in the same port, basically this: iptables -t nat -A OUTPUT -p tcp ...
2
votes
1answer
25 views

How to apply ipfw rules to domains that resolves to multiple IPs?

Suppose I wanted to use ipfw to throttle uploads to youtube. The uploads are made to upload.youtube.com but this domain resolves into multiple different IPs (which also appear to change over time). ...
0
votes
0answers
91 views

not all packets forwarded by pptp VPN server

I have the following setup: +------+ +---------+ ppp0---------+ |router| | A +-----+---+-----+ B | | R | ...
-1
votes
1answer
49 views

Route traffic to a destination to another destination using iptables

How to route traffic to a destination to another destination and receive response using iptables I have two vps on cloud. Lets say VPS-A and VPS-B. If a request to 8.8.8.8 generated from VPN-A, I ...
0
votes
0answers
46 views

Forward traffic from specific ip addresses to another port iptables

I can't figure out the syntax to forward TCP traffic from specific ip addresses to another port using ip tables. Lets say I want any TCP traffic from 1.2.3.4 to port 80 to be forwarded to port 81. ...
1
vote
0answers
61 views

Site to Site VPN - Openswan and CISCO A2A

Below is the diagram that the VPN connection between Openswan server and CISCO A2A. client A and B are remote hosts with static ips. client X and Y are behind the Cisco firewall. I can see ...
0
votes
1answer
119 views

How to permanently disable firewall in Red Hat Linux

I have followed the below steps to disable the firewall in Linux. After reboot, again firewall is enabled. How to disable firewall permanently? Login as the root user. Next enter the following three ...
0
votes
2answers
123 views

Iptables, allow common ports, block the rest

I want to allow people to connect to ports 22, 80, and 443. Also I want to be able to do DNS lookups from my server. Here's what I'm trying: iptables -A INPUT -m tcp -p tcp --dport 1 -j ACCEPT ...
0
votes
0answers
17 views

Block all outgoing ports from iptables.

I have a windows xp machine running specific application which can be access by single port (27500). there is nothing else i want to access on this machine. If i block all outgoing ports from this ...
0
votes
1answer
63 views

iptables does not seem to be applying SNAT to packets sent on a raw socket

I'm writing packets from a user space program to my wireless interface wlan0. I've set up a SNAT rule with iptables as follows iptables -t nat -A POSTROUTING -o wlan0 -j SNAT --to 192.168.1.3 And ...
1
vote
1answer
44 views

Open ports in Ubuntu 13.10 server

Im setting up a realtime gameserver fps-game, and then i need to configure ports. Just to mention, i will setup multiple servers for this game on the same ip address, which means i must open multiple ...
0
votes
0answers
160 views

How to redirect all data through a proxy on Tomato?

My proxy is Squid as an external machine. My router is a WRT54GL with tomato. On the router, I wrote this for the firewall script. It nicely connects to the proxy, but when try to visit any page it ...
0
votes
0answers
33 views

How to IP redirect all requests to public ip back to router

Using OpenWrt Backfire 10.03.1 on Linksys WRT54GL. Till today my ISP's modem used to loopback all traffic with self-destination IP back to itself. (for example if my WAN IP is 8.8.8.8 and I perform ...
0
votes
1answer
90 views

Restricting access to iOS apps based on time of day

I'm looking to set up something on my iPhone and iPad that works like SelfControl on my Mac. I get distracted by Facebook, and would like to restrict my access to it except during certain times of ...
1
vote
1answer
145 views

OpenWRT Firewarll INPUT Chain allowing everything?

I haven't done anything to my the default firewall rules except open a port for ssh from the wan and add the rules for OpenVPN as defined in this tutorial: ...
1
vote
0answers
301 views

Intermittent disconnections when using OpenVPN over SSH tunnel; possible iptables issue?

I've recently set up a Debian Wheezy server with OpenVPN to help out some friends in areas where internet censorship is a problem (including the blocking of VPN traffic in general). To overcome this, ...
0
votes
1answer
53 views

Port Forwarding with the real IP-address

How to implement port forwarding, so that would be displayed on the host real IP and non-IP machine, as it comes with SNAT DNET with IPTABLES The scheme is about the The machine-HETE with IP ...
0
votes
1answer
29 views

CentOS - ipTables

I have some questions about ipTables. Is it possible to open all ports between 2000 and 6000 and then have 2245, 5435,5434 closed? Is it possible to open some ports from a ip address? Eg. The only ...
0
votes
1answer
581 views

CentOS 7.x iptables

I have manually edited the /etc/sysconfig/iptables file in my CentOs 7.x installation , I have two entries and two processes running at the respective ports. I am able to telnet/access port 2181 but ...
0
votes
1answer
48 views

Need help converting some linux commands to OSX

I want to convert some linux commands into OSX. (Mavericks 10.9.4) root@bt:/# /etc/init.d/apache2 start (will "sudo apachectl start" do the same?) root@bt:/# echo “some Site Goes Here!” > ...
0
votes
1answer
326 views

squid proxy slow response

We are using the squid proxy in our setup and implemented as transparent proxy with user authentication. Before couple of days, while we are trying to setup the iptables the squid started performing ...
0
votes
0answers
113 views

How to correctly configure iptables on a laptop?

I have run these commands (tried switching the order too) because I want to set up a firewall on my laptop so that nobody can connect to it (except of course in response to a connection I've made): ...
0
votes
1answer
105 views

Why doesn't SpeedTest.net Upload work in Windows when using a Debian-router?

There is a FTTx connection. I connect ISP cable to the WindowsXP pc, setup PPPoE. SpeedTest.net shows normal Upload / Download. Now I connect ISP cable to router with Debian 7.5 installed, set up ...
0
votes
1answer
52 views

ip6tables: how to handle periodically changing prefix?

My ISP provides me with native IPv6 (unfortunately DS-Lite for v4) and I'm using SLAAC for the clients in my local network behind a broadband router. As I don't trust the router (which is configured ...
0
votes
0answers
524 views

udp client sending ICMP “port unreachable” when receiveing messages from the server

(Note: I moved this question from StackOverflow, because it's to be considered off-topic there, better fits here, and still unsolved) I have a udp client using luasocket, basically doing this (with a ...