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

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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 ...
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1answer
378 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 ...
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1answer
4k 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 ...
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1answer
3k 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?
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1answer
13k 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 ...
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1answer
631 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 ...
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1answer
2k 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 - ...
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1answer
424 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 ...
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4answers
125 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.).
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1answer
12k 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 ...
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5answers
4k 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 ...
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1answer
332 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 ...
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2answers
2k 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 ...
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3answers
1k 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 ...
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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
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1answer
373 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 ...
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2answers
9k 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 ...
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2answers
622 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 ...
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3answers
7k 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 ...
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1answer
407 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 ...
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2answers
1k 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 ...
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2answers
316 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 ...
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1answer
1k 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 ...
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1answer
6k 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 ...
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3answers
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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, ...
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0answers
382 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 ...
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2answers
4k 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 ...
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2answers
453 views

What does this rule mean

When I run sudo iptables -L, I get: Chain INPUT (policy ACCEPT) target prot opt source destination REJECT tcp -- anywhere anywhere tcp dpt:www ...
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0answers
389 views

iptables, forwarding between interfaces

I'm trying to setup a router using iptables. But, after a lot of examples I've tried, I can't get anything to work. My idea is to setup a box in between my Cisco and the main switch for firewall, ...
0
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1answer
381 views

Use a proxy which connects to the school proxy

How to get my computer use a proxy ON my computer, which connects to the school proxy ? The reason I ask this, is because I need all programs on my computer, absolutely the whole system to go through ...
2
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0answers
293 views

Firewall Iptables block everything and allow vpn

I would like to block all traffic on my ubuntu server with iptables and them allow only the protocols : HTTP, HTTPS, PPTP, L2TP, SSTP and OpenVPN I have tried many ways to do this, and I would like ...
0
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1answer
412 views

Iptables working strangely

I have Ubuntu 12.04 x64 installed in my laptop. I'm quite new to linux, and I wanted to specify certain rules for the iptables firewall. This is the saved config of my iptables: *mangle ...
0
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1answer
719 views

Can't open a port

I need to run an app on my computer which connects to local port 49100. So everything runs on one computer. I tried adding rules to gufw, firestarter, manually: sudo iptables -A INPUT -p tcp --dport ...
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1answer
480 views

How to enable Apache Solr service on Rackspace Ubuntu Server?

We have setup Apache Solr on Rackspace dedicated ubuntu server. But, I think because of Firewall this service is not available. I tried adding following line as per Rackspace documentation: ...
3
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1answer
456 views

WAN access problem

I was desperately trying to set up my system as an externally accessible machine in the past 4 days without luck. Must say , it was a great journey so far, learned a lot about linux networking in ...
2
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1answer
245 views

Using Ubuntu as a gateway for monitoring and possibly IPS IDS within Active Directory

Ok, I've searched for days, maybe you can point me in the right direction. I have an MPLS scenario with a shared gateway in a multi-domain M$FT AD environment. On the inside of the MPLS all of the ...
3
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1answer
1k views

Writing a simple firewall with iptables

I'm learning how to use iptables and I'm writing a very simple firewall on Ubuntu. Using just the filter table, I added the following rules iptables -P INPUT DROP iptables -P OUTPUT DROP iptables -P ...
3
votes
1answer
809 views

Iptables script

What is the proper place to start/stop iptables script? Currently I have placed it into /etc/init.d and it has start/stop options. However I don't think it is the best place. The other two according ...
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0answers
275 views

IPtables forwarding [closed]

I have a server with Zentyal 3.03(ubuntu 12.04) lts. It has 3 lan card. eth0 - dhcp fast internet (i pay for it) eth1 - static slow internet (it's free for the school) eth2 - LAN I can reach the ...
10
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3answers
1k views

Replacing my firewall rules

I've had an init script for many years that configures iptables for me and it has worked like a champ until now. After upgrading from 10.04 to 12.04 I started having firewall problems where the ...
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2answers
904 views

List firewalls on the local machine

In Windows besides the Windows firewall a user could have installed a firewall program, or there is another service listening to that port. In Ubuntu how can I see what blocks/filters open ports? ...
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1answer
168 views

iptables -L lags on non localhost or anywhere address

I am trying to configure iptables for ubuntu 10.04 and I have a problem with iptables -L lagging on rows where the destination or source address is not localhost or anywhere. The following entries ...
3
votes
1answer
4k views

How to delete or unblock an IP address listed in IPtables firewall?

I am trying to delete an IP address that appears listed on the server's IPtable. I'm using the following command to list the IPs: iptables -L INPUT -n --line-numbers Giving me a result like: ...
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2answers
3k views

Iptable Rules Https block in Zentyal

I am using Zentyal. I want to block https://www.facebook.com with iptables rules. Can you please tell how to block it for my organization's network?
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votes
2answers
3k views

How to forward an Internet connection to another network?

Can somebody please make a short & sweet tutorial telling how to forward an Internet connection to different network interfaces in Ubuntu...? This is the idea: I'm using a 3G usb modem to get ...
3
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1answer
9k views

Redirect requests mapped to a DNS IP Address

For this command lines: sysctl net.ipv4.ip_forward=1 iptables -t nat -A PREROUTING -p tcp --dport port -j DNAT --to-destination ip:port iptables -t nat -A POSTROUTING -j MASQUERADE I can reroute ...
2
votes
1answer
905 views

How to send packets via a pptp vpn tunnel?

I'm trying to send certain port traffic through my ppp0 interface it's a pptp vpn tunnel, First, I'm using a wireless usb interface, I connect up to my access point, then I initiate my vpn, there is ...
5
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2answers
4k views

'ip rule flush' breaks all connectivity

I'm configuring some network stuff, and every time I try something the connection breaks. Thinking that I must be configuring something incorrectly to break all connections, I did a bit of ...
2
votes
1answer
558 views

Linux Firewall NAT Port Forwarding Issues

At my home I have a Linux server (it's only job is NAT, DHCP, and DNS) with Ubuntu 10.10 Server 64-bit. I have webmin installed on the server too, but I do know my way around a command line quite ...
5
votes
3answers
2k views

How to host an AP or a hotspot?

I'm running Ubuntu 12.04 as a virtual machine on my Mac. Since I am unable to get the virtual machine to have full access to my WiFi card, I bought another USB WiFi card to use. This is my WiFi card. ...