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

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Port redirection for a specific (dynamic) IP using iptables script

What I want: Incoming TCP and UDP connections on port 900 from the resolving IP address of myip.dyndns.org (dynamic IP) should redirect to port 5050 on the local machine. All other IP addresses ...
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0answers
76 views

What is UFW's approach towards rules order for overlapping rules?

I need to enable UFW in my Ubuntu 14.04 Server having these conditions: - I want to deny all incoming and outgoing on all ports (and protocols) but: - I want to allow all incoming and outgoing on a ...
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1answer
1k views

How do I remove all the ufw chains from iptables?

I've removed ufw and I want to get rid of all the chains it leaves behind. How can I do that easily?
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1answer
499 views

Setup NAT on Ubuntu 14.04

I'm trying to insert my desktop between an appliance and the rest of the network to monitor the traffic coming off of it due to some security concerns. I'd like to setup NAT so that the devices behind ...
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1answer
374 views

How do I set up a firewall/iptables using rc.firewall?

I am new to Ubuntu and am having a bit of trouble getting my firewall set up for my Network Security class. We are set up with 3 virtual machines - a Gateway, a Server, and a Client. We are supposed ...
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1answer
695 views

The server cant resolve host names

Please help with the following problem. Server is running under Ubuntu 14.04 server 32x. IP tables: INPUT DROP [0:0] :FORWARD DROP [0:0] :OUTPUT ACCEPT [0:0] -A INPUT -p icmp -j ACCEPT ...
0
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1answer
738 views

Redirect iptables to apache without internet connection

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 ...
2
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0answers
177 views

How do I find which OS layer (iptables, rp_filter, etc) is dropping a packet?

Let's say that I'm running a ping towards a machine and I see from tcpdump that the icmp echo reply is being received at the ethernet port but the ping program is not getting it. So I know that ...
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2answers
432 views

How can I prevent being locked out after changing the iptables default policy?

I am working on a experiment when I (client) ssh a gateway and run sudo iptables --policy INPUT DROPthen the gateway doesn't accept any communucation(or input) from my client. By running sudo iptables ...
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1answer
753 views

How to route inbound traffic on one interface to another interface in the same machine?

I have searched the forums, but can't find a solution that addresses my use-case exactly. I need to do this on a remote machine and so don't have a lot of latitude to get this wrong (and possibly lock ...
4
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1answer
9k views

Using Ubuntu 14.04 as router with iptables, clients can't go online. Probably DNS issue, iptables setting needed

CORRECTION 3: SOLVED! I needed to add the the official DNS server of my departement's VLAN as DNS to the clients. I've read through a large number of posts about iptables issues when using Linux as ...
0
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1answer
562 views

network bridge not forwarding traffic from span port on router

I want to run several security network tools in LXC containers like ntopng, suricata, snort, etc. I hooked one of my server's NIC's up to a port that is spanned to my firewall... so basically this ...
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0answers
28 views

NATing ports selection using hardware detection

I have a linux box to be used as a router with a wlan port in AP mode. The internet input to the board may come from either an eth port (WAN mode) or another wlan port. There is also VPN running that ...
0
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1answer
171 views

Failover/ gateway issue. Help please

hope someone can help, this would be excellent. I’ve ubuntu DHCP server (10.04), which works great (many thanks to everyone who helped me in this excellent forum). This server has 2 cards, eth0 for ...
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1answer
3k views

Open port 8080 on 14.04

I need to insert into iptables to open 8080. With the iptables I looked at iptables -L it is so complicated and has many division I am not sure where to put the rule to open the port. Here is my ...
0
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1answer
3k views

what could be blocking port 5060 on my ubuntu 14.04?

I have a ubuntu 14.10, and am trying to telnet into it via port 5060 but I keep failing. I always get the message "Connection closed by foreign host". I checked my iptable, it is default policy to ...
0
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3answers
4k views

The program 'iptables' is currently not installed

I am a newbie, so my apologies up front. I am trying to get DansGuardian installed (which I believe I have) and working. To get it working I need to filter IP traffic through the app via iptables. ...
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0answers
1k views

vagrant, port forwarding, and iptables

Background: I am a newby learning Python and Django. Because my machine is Windows 8.1, I installed Vagrant with Precise 64. At first things were fine, then suddenly, NONE of my projects in the VM ...
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0answers
484 views

Connection refused - despite iptables rule is accept and port is open

I am trying to setup an ssh service. I am behind a residential router, and connecting to the desktop on a laptop computer. I use the the local IP of the desktop (192.1 ...) for address. The ...
0
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2answers
641 views

keep iptables up to date

I've installed iptables-persistent (Ubuntu 14.04) with the impression that it automatically saves iptables on shutdown but that appears not to be the case? It seem to load saved rules at startup but ...
0
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1answer
2k views

iptables-persistent not uninstalling

I'm running Ubuntu 14.04 and I simply want to uninstall iptables-persistent to test something. As suggested here (http://www.installion.co.uk/ubuntu/saucy/universe/i/iptables-persistent/uninstall....
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1answer
279 views

Differences between UFW and GUFW

From what I have been able to piece together, the firewall that comes with Ubuntu is iptables, which is very complicated, so an easier way to access the firewall is through UFW and GUFW. UFW is ...
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0answers
549 views

Why aren't these ufw rules working?

I'm trying to configure ufw to only allow connections to 3 ip addresses on my local network, and deny everything else. Here's the commands I'm using: yes | sudo ufw reset sudo ufw default deny sudo ...
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1answer
674 views

Why is iptables getting double rules?

I have a server running Ubuntu 12.04. A couple of reboots back I started noticing that iptables rules get doubled upon reboot. This is what I get after a reboot (with added line breaks): $ sudo ...
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1answer
1k views

What are the IP addresses in my iptables chain FORWARD settings in a Dokku/docker setup?

I've been playing around with Dokku on DigitalOcean (following this guide) and I'm trying to understand current firewall settings. So here's my setup: Ubuntu 14.04 Dokku Docker (as part of Dokku) ...
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1answer
2k views

How do I write an iptables rule to limit Internet bandwidth usage of user or IP address

How do I control or limit Internet bandwidth usage of users/computer/IP address in network with the help of iptables rules? I have one static IP address which provides Internet (that is, WAN). I ...
0
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1answer
136 views

keep getting added to hosts.deny + iptables

I am confused to why this has started to happen. On my local network, if I click 10-20 apache/http links my server will decide to add me hosts.deny file and block me on iptables. Its not just apache,...
0
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1answer
775 views

Torrent applications getting slow download speed?

Allowed port in iptables with this command sudo iptables -A INPUT -p tcp --dport 6881 -j ACCEPT. After ran this command, Transmission client port shows open but in next 30 seconds it's shows closed. ...
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1answer
669 views

How to use multiple IP block list in Ubuntu peer 2 peer programs?

I would like to use several public IP block list (IP filters) in qBitTorrent or Vuze, on Ubuntu 14. What is the easiest way to do that and to get the lists updated? Note: This is not a discussion ...
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1answer
314 views

Ubuntu wifi hotspot cannot share network

I am using hostapd for my WiFi hotspot, and I can connect my WiFi perfectly until today. I have isc-dhcp-server and bind9 running on my laptop, because I want my laptop to be dhcp and dns server. ...
0
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1answer
2k views

How to open the ports on firewall in Ubuntu? [duplicate]

I'm pretty new to Ubuntu. I just want to open the most common ports namely FTP (port 20 TCP/UDP) HTTP (port 80 TCP/UDP) SMTP (port 25 TCP) ETC I've tried all the ways in iptables, ufw, and gufw. ...
0
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1answer
242 views

Iptables Issue can't SSH Remote Machines

I want to SSH to 192.168.1.15 Server from my machine, my ip was 192.168.1.99 Source Destination was UP, with IP 192.168.1.15. This is LAN Network there are 30 Machine's Connected to the network and ...
0
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1answer
257 views

Help writing server script to ban IP's from a list

I have a VPS that I use as an openvpn and web server. For some reason, my apache log files are filled with thousands of these hack attempts: "POST /xmlrpc.php HTTP/1.0" 404 395 These attack attempts ...
0
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2answers
362 views

Using Apache2 to set up a basic webpage

I am having a problem with a test page I set up for my website. The config file (index.html) looks like this <html> <head> <title>Welcome to website.net!</title> </head> ...
2
votes
5answers
15k views

Can't ssh into server, connection refused

I can't ssh into my server. The server is on a private network administrated by me. Ubuntu is version 14.04. This started when I changed to a wired ethernet card. The client is MobaXTerm (latest) ...
4
votes
1answer
3k views

Iptables rules no longer honored

I installed Ubuntu Server 64-bit 14.04 a week ago. It worked fine for one to several days, then out of the blue, iptables became meaningless (I noticed FTP and such are down ). Only ports 22, 25 & ...
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0answers
253 views

VirtualBox, Ubuntu clients, internal network proxy to supply internet

Probably this question was asked many times, but I seem to be unable to find proper solution. Here is my setup: Two virtual machines(Ubuntu 12.04) M1 and M2. M1 has 2 network adapters: eth0 set ...
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2answers
10k views

What is MASQUERADE in the context of iptables?

In Iptables many times I see the target MASQUERADE. What is that. I searched and find lots of things. But I need some one explain me what MASQUERADE is in a so easy way? **If you bring an example ...
0
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1answer
3k views

Redirecting external ports to local ip

I have a ubuntu 13.10 server and a registered domain name. I have a web server on my 192.168.24.1 machine and a ftp server on my 192.168.24.2. Using iptables I want: 1) people who write : http://...
2
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0answers
3k views

Not pinging with host-name and can't ssh using hostname [duplicate]

I have setuped a DNS server in Centos6.5 and its working with every client machines other than ubuntu, now i have issue with ubuntu While im trying to ping from desktop machine to DNS server as ping ...
11
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4answers
7k views

Is someone trying to hack into my server? What can I do?

A few weeks ago I posted a question here about some ssh issues I was having with an Ubuntu 12.04 box. Fast forward to today and I am trying to allow someone else access to the machine, but they keep ...
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1answer
141 views

iptables command to give internet to my guest OS via virtual box

Based on this link there is a difference between Host-only network and NAT. So I want to set the LAN connection between my host -14.04 ubuntu- and my guest XP by Host-only network. How I can give ...
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1answer
4k views

Firewall rules for transmission

I have transmission installed, which listens on the default port 51413. I have tried opening everything for this port. iptables: Chain INPUT (policy ACCEPT) target prot opt source ...
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1answer
249 views

How to block ip forwarding for specific remote ip address

I use ubuntu as gateway for several hosts. I need advise how to block ip forwarding for specific ip address or specific ip range? I tried to block ip via ufw deny rules, but it looks like ip ...
0
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1answer
87 views

iptables ruleset blocking all network activity?

I've gone through numerous trial and error to recently discover that my iptables result is the culprit of blocking all LAN and WAN activity. I know this, because if I comment out the last line in my ...
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0answers
313 views

Port forwarding out multiple VLAN interfaces that have same IP address

So I have an Ubuntu machine with multiple VLAN on an interface eth1 and each VLAN has the same IP address (172.16.0.2). I need to be able to simultaneously telnet into a rack of devices that are also ...
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1answer
2k views

Where is /etc/sysconfig/iptables-config in 14.04

Where is /etc/sysconfig/iptables-config in 14.04 I can't comment in this thread because I do not have a reputation of 50 Configuration of iptables (verfication, actives services, allow FTP)
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1answer
2k views

Dnat prerouting does not work on Ubuntu 14.04

I've got a Ubuntu 14.04 server used as firewall, router, dhcp, dns and proxy. Everything works properly from inside to the internet, but the forwarding from outside to the inside network doesn't work. ...
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0answers
8k views

ubuntu 14.04 default firewall rules

I would like to know exactly which scripts are responsible for default iptables rules (no ufw, no gufw) in Ubuntu Server 14.04. After fresh installation even with ufw disabled (by default) there are ...
0
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1answer
1k views

Squid as proxy is only allowing https traffic

I have installed Squid with Dansguardian and configured it exactly as instructed here. It works fine for https traffic, which is allowed through just fine. However, squid doesn't allow any http ...