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

learn more… | top users | synonyms

3
votes
1answer
292 views

Setting up catch-all with iptables

I'm trying to setup a iptables which only allows traffic in via ssh and a catch all that blocks everything else coming into computer. The iptables -L output looks like this Chain INPUT (policy ...
1
vote
1answer
2k views

ntp date not showing the correct time [duplicate]

I was having an issue in which the time my ubuntu machine was showing is 5 hours ahead of my standard time. So I installed ntpd for that using apt-get install ntp after that I restarted ntp but ...
3
votes
1answer
200 views

Prevent a user from accessing the internet, except for certain websites

I'm trying to prevent a specific user from receiving traffic from any sites except specific sites on a whitelist. The easiest way to do this seems to be with iptables, but I haven't been able to get ...
2
votes
0answers
306 views

How do we allow a certain mac address in a FORWARD chain through iptables?

I set the iptables rules in default. # IPTABLES IN DEFAULT iptables -P INPUT ACCEPT iptables -P OUTPUT ACCEPT iptables -P FORWARD DROP How will allow a certain mac address in a forward chain? I ...
2
votes
0answers
1k views

IPTABLES > MAC Filtering

I am newbie. I tried DHCP Mac filtering is not enough to secure our networks and I think iptables will... This is my concept: I set a new laboratory (LAB) network. My other network is connected to a ...
1
vote
2answers
6k views

Create table in iptables

I want to create a custom table using iptables so that I can add my custom chains in it. But I doesn't see any option to do that. I tried to search for it but didnt found anything. Please Help.
2
votes
1answer
3k views

Forward TCP Connections with Iptables

I receive connections to my server from several ip addresses I want to route these connections just like rinetd does but based on the ip the connection is coming from to connect to a specified host. ...
1
vote
0answers
536 views

UFW Firewall Rules, has a hole in it. Please help

Can someone please look at the below output for me. I have my UFW on deny/deny, and here are the rules. But if I leave my Ubuntu Server on, with a Windows XP VM, and let Instant Messenger run in the ...
0
votes
1answer
40 views

About ubuntu as server and configuring ip tables [duplicate]

Please help me to setup a linux based server machine for sharing internet connection in my network. Since I am a new user, please assist me ...
1
vote
1answer
159 views

iptables help needed in 1304

I've setup my raring-ringtail machine and decided to use iptables after removing ufw to have more control over my network security. However, I'm stuck at one point. First, I've set default policy to ...
2
votes
1answer
2k views

OpenVPN - Routing issue

Server: Ubuntu 11 (Openvz VPS) Client: Windows 7 Issue: clients connect successfully to VPN, but loss of internet access once inside the VPN. Facts: Everything mostly defaults Is a ...
7
votes
0answers
317 views

How can I run a command from a qml script? [duplicate]

I'm working on an Ubuntu Touch app that needs to modify iptables and do various other things that requires interaction with the command line. I found this and I understand that it must be done with a ...
1
vote
2answers
155 views

Simple shell script

I am quite inexperienced when it comes to Linux and now I am setting up the system. What I want to do is to write a shell script, that will do two things: Start i2prouter - as I do not want it to ...
2
votes
1answer
755 views

Shorewall IP Forwarding Problems in 12.04 LTS

Internet connectivity through my 12.04 LTS shorewall box is spotty at best. Ping works both locally and to the internet with no dropped packets (from both the box itself and internal LAN). HTTP ...
1
vote
0answers
419 views

New Server - apache will not serve outside LAN

New server, running well 12.04 LTS on HP ML350. Apache = great, inside our LAN. Apache = timeout, from WAN (NAT forwarded from firewall). I have cleared all Iptables, read & checked every ...
4
votes
1answer
572 views

Could someone tell me whether my OS is communicating with the internet?

I edited iptables so that when the VPN service is disconnected, no program will access the internet. Well, I did an experiment. I disconnected the VPN service manually and immediately did a ping by ...
1
vote
1answer
186 views

Blocking MAC Address does not work on DHCPv6 request

I blocked a MAC address of a client on my DHCP Server running on Ubuntu 12.10 using iptables -A INPUT -m mac --mac-source -j DROP But I am still getting DHCP requests from the client and the ...
1
vote
1answer
612 views

Block all non-squid traffic for PPTP users

I have squid running on a transparent proxy (port 3128) and VPN clients connecting + ip forwarding via PPTPD. I want to allow users to connect to port 80 (3128) but block all other TCP traffic. I am ...
0
votes
1answer
434 views

Change UDP port with iptables for VPN clients

What I want to do is say that for all UDP connections on interface ppp0 that have a destination port of 53, change that destination port to 1053. I am attempting to change the destination port of UDP ...
2
votes
2answers
2k views

How do I make Youtube videos stream faster on my ubuntu?

According to this article, http://thetechblock.com/how-to-stop-isps-slow-youtube/, I can make Youtube videos stream faster on Linux, but I am not entirely sure how to carry out similar commands on the ...
0
votes
1answer
67 views

How do I know if iprules are used?

I followed this: How to save rules of the iptables? And created this "/etc/iptables.rules": # Generated by iptables-save v1.4.12 on Sun May 19 18:42:18 2013 *filter :INPUT ACCEPT [429624:571594561] ...
3
votes
1answer
4k views

Internet connection sharing without Network Manager

I followed these instructions for setting up a shared internet connection with iptables. Specifically, I: Added a network interface for my second NIC in /etc/network/interfaces like so: auto eth1 ...
0
votes
1answer
2k views

Something is closing port 443?

I have Ubuntu 12.04 Server installed and serving a Ruby on Rails app with Apache and Passenger. I'm using iptables to control traffic. Yesterday, I setup Apache to use SSL for the site. After setting ...
0
votes
1answer
505 views

I can ping some host but not all from network on OpenVPN tun

I have a network I want to connect to which is behind a firewall (iptables). On the same PC there's the OpenVPN server. It's directly connected to the Internet. I can connect to the server through ...
1
vote
1answer
398 views

redirect traffic from 2 Ubuntu external NICs to specific internal hosts

I am having problems redirecting incoming traffic to 2 external facing interfaces on my Ubuntu 12.10 server to 2 separate internal hosts. I am able to redirect incoming traffic on my eth0 just fine to ...
1
vote
1answer
5k views

Iptables on Ubuntu Server does not open ports

Does Iptables need ufw to work? I tried unsuccessfully open 4447 on my ubuntu server 12.10 using iptables. Did: server:~# iptables -A INPUT -p tcp --dport 4447 -m state --state ...
1
vote
1answer
4k views

UFW 'default deny incoming' doesn't work

I have UFW enabled, 'default deny incoming' set and no any additional rules, but I still can access all ports from other PCs. I have to manually block each port. What can be wrong?
7
votes
1answer
14k views

iptables doesn't redirect http traffic to my Squid proxy!

I arranged a transparent Squid proxy which listens to port 3128 on localhost, to block some web sites. I've tested the proxy using Firefox, and it works. Then I ran this, hoping to redirect all the ...
0
votes
1answer
658 views

Iptables proxy host on port

I have 2 servers from 2 different companies The first server is a VPS where i host my websites (lets say it has IP 5.5.5.5) The second server is a Minecraft server (lets say it has IP 6.6.6.6) On my ...
2
votes
1answer
3k views

Webmin Port Forwarding

I have not been able to figure this out at all. I have 1 Lan IP address and 5 external static IPs: eth0: 10.0.0.1 - internal lan ip and router IP. eth1: xx.xx.xx.217 - external eth2: xx.xx.xx.218 - ...
0
votes
1answer
462 views

Forward [open] Ports 7777; 2106

Hi i am new to Ubuntu (12.10) x64 Trying to forward ports for gameserver on my pc (Lineage II) Ports are opened in UFW Ports are opened in my Router Even if i disable UFW others still cant login to ...
0
votes
4answers
127 views

Simply safe internet access

Is it necessary to configure a firewall like iptables or firestarter when the goal is only to surf safely? For me, there is no need to open any port (i.e. samba, etc.).
10
votes
1answer
13k views

How can set these iptables rules to run at startup

I usually run my iptables rules whenever I login. From the terminal I type ; sudo sh firewall.sh Setting up my sister's computer, I want to give her some basic firewall protection. She wont be ...
0
votes
5answers
5k views

fail2ban or denyhosts to block invalid username login attempts

Is there a way to automatically block IP address when a user tries to login as any invalid username? I already have: [ssh] enabled = true port = ssh filter = sshd logpath = /var/log/auth.log ...
0
votes
1answer
357 views

Why is drop box always trying and failing to connect to me on a high port in iptables logs?

Continually getting message in logs: IPTables Packet Dropped: IN=eth1 OUT= MAC=c4:17:fe:65:51:f8:20:76:00:aa:98:78:08:00 SRC=199.47.216.148 DST=192.168.1.102 LEN=218 TOS=0x00 PREC=0x00 TTL=54 ...
1
vote
2answers
3k views

iptables and skype

Does anyone here use iptables with skype? The only way I have been able to get it working so far is to allow all the high ports- something like iptables -A OUTPUT -p UDP --dport 1024:65535 -j ACCEPT ...
1
vote
3answers
2k views

How to add an IP(all ports) and how to remove that ip?

I need to connect to my computer remotely(all ports), but that ip changes. I have everthing figured out on how the comp woukd know my current ip, but i don't know how to add an ip on all ports and ...
1
vote
1answer
1k views

How to allow PPTP VPN access through APF firewall

I'm attempting to connect to a PPTP VPN. I have opened ports 47 and 1723 in the ingress rules. When APF is turned on, it fails. When APF is turned off, it works fine. I have turned on as many logging ...
0
votes
1answer
397 views

Want some advanced configuration with ufw

I've read the ubuntu developer docs regarding the ufw here, but couldn't find what I was looking for. It allows me to set rules for controlling in/out traffic based on source IP or port numbers, but ...
0
votes
2answers
10k views

Configuration of iptables (verfication, actives services, allow FTP)

I’m experimenting with IPT's (iptables) in Xubuntu. First experimentation wato allow all OUTPUT traffic and block all INPUT except already existing TCP connections can somebody verify if these are ...
1
vote
2answers
671 views

iptables forwarding all excluding local server

These are the rules I am using: iptables --flush iptables --table nat --flush iptables --delete-chain iptables --table nat --delete-chain iptables --table nat --append POSTROUTING --out-interface ...
3
votes
3answers
8k views

Error message when entering iptables command (table does not exist)

I have been trying to install Spotify, but when logging in I get a message saying I have an error 101. This appears to be related to either my proxy settings or to my firewall. Following instructions ...
1
vote
1answer
426 views

Migrate Debian firewall rule to Ubuntu

My old Debian firewall died and I'm migrating saved rules to Ubuntu this way: iptables-restore < firewall_config I get this error: Bad argument `192.168.1.0/255.255.255.0' Error occurred at ...
0
votes
2answers
2k views

Problems allowing outgoing multicast in ufw

I am having problems configuring the uncomplicated firewall (ufw) to allow outgoing multicast traffic. I am blocking all in and outgoing connections as the default policy. I have supplemented with the ...
2
votes
2answers
334 views

cannot establish TCP connection with VPS

Vince Stewart I have a VPS on Ubuntu 12 and a home computer on Ubuntu 12. I have a Java application on the VPS which opens a tcp socket listening on port 4000 and also an Http listener. My ssh service ...
3
votes
1answer
2k views

iptables-persistent doesn't load rules on boot

I have few iptables rules which I want to use permanently. So I've installed iptables-persistent and save my rules in /etc/iptables/rules.v4 and /etc/iptables/rules.v6. Also I turn on autostart for ...
1
vote
1answer
7k views

How to allow my vpn client access to remote LAN(eth1)?

My ubuntu server has two if: eth0, eth1. eth0: Public IP eth1: 192.168.0.2 I've configure down eth0 for a vpn server using pptpd. The vpn ip_range is 192.168.100.234-248 #/etc/pptpd.conf ...
5
votes
3answers
6k views

Is there a rule for iptables to limit the amount of SYN packets a /24 range of IPs can send?

How can I block entire C class IP blocks when they send too many SYN packets to my ubuntu 12.04 server? Example of what I see during a SYN flood attack: Each different IP only sends 1 SYN packet, ...
2
votes
0answers
392 views

squid + iptables not working

I would like to make a proxy on my ubuntu VM for testing a PHP script that must use proxy. I installed Squid and made some things with iptables command. I wrote : sudo iptables -A OUTPUT -p tcp ...
12
votes
2answers
5k views

How to configure an OpenVPN Client Router

I am attempting to set up an OpenVPN Router so that I may connect my tablet (wireless) and Blu-Ray (wired) to a paid VPN service in another country on Ubuntu 12.10. I have successfully done this using ...