a technological barrier designed to prevent unauthorized or unwanted communications between computer networks or hosts

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33
votes
5answers
9k views

Why is the firewall disabled by default?

Why is ufw firewall included in Ubuntu, when it is not enabled and pre-configured by default? Most users don't even know it is there, because no GUI frontend is provided.
16
votes
5answers
5k views

Is there a preinstalled or automatic firewall?

Does Ubuntu come with a preinstalled or automatic firewall? If not, do I need one? I've read some articles about the advantages of linux over other operating systems about security (no need to have ...
18
votes
9answers
14k views

How to control internet access for each program?

I would like to use a software to control which program may connect to the internet. I know that this behaviour is associated with the word "firewall", but some Linux users are very upset if somebody ...
5
votes
1answer
8k views

MySQL server not accessible from remote machine

I have installed MySQL server in my local Ubuntu server (11.10). I can't connect to the server from a remote machine. When I tried:- nmap localhost , It shows the following PORT STATE SERVICE ...
6
votes
3answers
960 views

How can a non-geek set up a proper firewall?

Maybe a non-geek that knows of the existence of a firewall is already some kind of a nerd. If you have been a windows-user then it was rather easy to set up a firewall (I don't know if it was a good ...
9
votes
3answers
17k views

How can I make a specific set of iptables rules permanent?

Is there a "best practice" or standard to make a few iptables rules permanent? I mean: automatically applied upon a system reboot? I am using a VPS with Ubuntu Server 10.04 LTS (Lucid Lynx). Thank ...
14
votes
8answers
6k views

Alternative to Little-Snitch app-firewall?

I'm trying out Ubuntu. Been a Mac user. I like ubuntu a lot but I'm uncomfortable not having an app-firewall that reports what connections are being made to the internet. I find it unnerving to not ...
7
votes
2answers
2k views

How to restrict user's access to the internet for time intervals?

I want that one of the users (not in the sudoers list) have Internet access from 14:00 until 16:00 and from 17:00 until 18:30. Is it possible? Can I set different time intervals for different week ...
1
vote
1answer
721 views

How to configure a firewall that only allows a few webpages and dropbox and U1 services?

Can anyone give a step-by-step how-to that explains how to block all outgoing internet traffic to all websites, but allows only a selected list (needed for working, fi. online dictionaries) allows ...
5
votes
2answers
8k views

System log error when running Firestarter configuration program

Running latest Ubuntu ver. 11.04. Using Firestarter firewall configuration (ver.1.0.3). When Firestarter is run, an error message is returned, "Failed to open the system log. No event information will ...
7
votes
4answers
13k views

What rules to use for UFW?

I've decided to enable the UFW that comes with Ubuntu just to make my system even more secure (especially after watching a video of a person whose computer actually got infected!), and I've enabled ...
6
votes
6answers
1k views

Do I need a firewall for my desktop?

I don't have a router, but I mostly use my desktop for online shopping and torrenting. So, do I have to enable the firewall? I hope not, because I'm really dumb and I don't think I will be able to ...
4
votes
1answer
398 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
4answers
1k views

Ubuntu One does not sync: firewall settings?

I'm new to Linux. I installed Ubuntu 11.04 on a partition and I love it, but Ubuntu One does not work. I created a free account and a directory Ubuntu One appeared automatically, as expected. I copied ...
49
votes
8answers
3k views

What are the risks of NOT using a firewall (home computer)?

Since a password is required to be a superuser (to install and modify programs), what are the risks to not use a firewall under Ubuntu ? More particularly if I am using a NAT router ?
20
votes
3answers
987 views

What automated intrusion notification/detection setup is good for home desktop use?

I've been using Linux for quite a while now and I always feel the need to have a passive software / script setup which can alert me of any suspicious network activities like scans, failed login ...
9
votes
1answer
777 views

Precautionary security measures for a home user? (firewall, antivirus, etc)

I just recently made the switch from Windows to Ubuntu, and I'm just a little paranoid when it comes to security measures. I've looked around and from what I've read, security is not as big a concern ...
6
votes
6answers
4k views

UFW firewall still blocking SMB despite adding rules

I have an Ubuntu PC with ufw firewall (GUI version). I have added the preset Samba service, in and out, and even tried adding the ports manually (135-139, 445, UDP and TCP, in and out), but it still ...
12
votes
8answers
3k views

Is a Firewall really necessary these days? [closed]

should I install something like gufw?
7
votes
4answers
1k views

Reverse Firewall or Application Firewalls?

Firewalls are typically employed to prevent bad "packets" coming in from the outside world. But these days we are mostly behind routers and a lot of that danger is mitigated by the router. The danger ...
7
votes
1answer
522 views

Getting Dynamic firewall from Fedora 15 into Ubuntu?

Just tried out Fedora 15 and noticed the pre-installed firewall application that I found much easier to use than any other previously tried out firewall manager. Definitely miss it at my Ubuntu ...
6
votes
2answers
4k views

UFW is not logging how do I troubleshoot?

I have set logging to high. I am not seeing any log messages. I do see the empty ufw.log file. No messages in dmesg
10
votes
3answers
844 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 ...
7
votes
2answers
8k views

“FirewallD not running” error when trying to install a printer

When trying to add my printer in a fresh install of 11.10 I get this error message. What does it mean, and what do I have to do? It worked fine in 11.04 (with hplip).
4
votes
3answers
6k views

Why UFW has to be (re)started at boot time if it's only iptables rule manager?

README from source package says: When installing ufw from source, you will also need to integrate it into your boot process for the firewall to start when you restart your system. Depending on your ...
3
votes
1answer
177 views

Docker is blocked by UFW

I have problem with Docker network in ubuntu 14.04. I have installed Docker.io from official repo and I've added DEFAULT_FORWARD_POLICY="ACCEPT" to /etc/default/ufw but my Docker containers still ...
3
votes
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 ...
2
votes
1answer
69 views

Need help to make this file work in iptables

I came across the following example of how to use iptables to block internet access when the VPN connection is terminated abruptly: iptables -A INPUT -i lo -j ACCEPT iptables -A OUTPUT -o lo -j ...
2
votes
2answers
442 views

UFW not blocking connections to docker instance

I have a webservice running inside a docker instance which was run using the following command: sudo docker run -d -p 4040:4040 .... My UFW rules look like this: ~ sudo ufw status Status: active ...
2
votes
2answers
2k views

How to block all but one or two websites without browser extensions? [duplicate]

I want to block all, but one or two websites. This question is therefore relatively close to, but different from the following Parental controls with different settings for different users ...
2
votes
1answer
4k views

How to allow remote connections to Flask?

Inside the system, running on virtual machine, I can access the running server at 127.0.0.1:5000. Although the 'remote' address of the vm is 192.168.56.101 (ping and ssh work fine), I cannot access ...
1
vote
2answers
919 views

Ubuntu - apt-get not working behind restricted internet access

I have Ubuntu 12.04 64-bit boxes running in a company but they have internet browsing and firewalls for security. When I do apt-get update or install it fails. But I have a remote server which ip is ...
0
votes
1answer
2k views

How to open a port?

I have ubuntu 12.04 and I'm not able to allow certain port in my firewall. So I basically said I will allow everything but it's still not working. Please help. nmap on this machine from other machine ...
4
votes
1answer
278 views

blocking all outgoing ports and its consequences

Is this the right way to block all outgoing ports? : ufw default deny outgoing But what are the consequences of doing this on amazon ec2? I'm running possibly unsafe perl scripts on my instance and ...
4
votes
1answer
1k views

Which port does Ubuntu Software Center use?

I have installed the gufw firewall utility and want to make a whitelist of ports (want maximum security, but whitelisting single IPs is currently too tedious). I have so far only entered ports 53 (for ...
3
votes
1answer
2k views

Do I need to activate the firewall? I only use Ubuntu for a home desktop use?

I am a novice at Ubuntu (12.04). I have it on my netbook which I use mainly for surfing the net, learning python and remote desktop into my work computer. Do I need to enable a Firewall type ...
3
votes
2answers
1k views

Is there any software for bypassing the firewall?

I am using ubuntu 10.04. Is there any software to bypass the firewall configured by my network administrator. I have seen my friend using software named ultrasurf in windows which bypasses the ...
2
votes
5answers
735 views

Blocking Remote Login

Last night, I was shutting down my server and I saw a message asking if I wanted to shut down a "pts/0" session. Odd, I thought. So I logged back in and did a finger and saw that there was someone ...
1
vote
2answers
1k views

How to disable Internet connection for a single process?

I know the PID of a specific process and I want to disable the Internet access for this process and only for this process, so other process can access Internet. Is there any way to do it? I ...
1
vote
1answer
222 views

How do I use “ld_preload” to control what apps can and cannot connect to internet?

I'm trying out Ubuntu. Been a Mac user. I like ubuntu a lot but I find it unnerving to not have any control over what apps can & cannot connect to the internet. I was advised that "ld_preload" can ...
1
vote
1answer
2k views

How can I set up GUFW so that only firefox connects to the internet

I only want http, https and DNS to be open. I'm having troubles with setting up port ranges in the UFW GUI. How do I input configs into the feilds? Basically, something along the lines of this, but ...
0
votes
1answer
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 ...
0
votes
1answer
557 views

Ubuntu Windows Installer - Firewall

I installed Ubuntu with the Windows installer to use it along side. I could not find anything to activate a firewall so I thought its inbuilt and running. However now I read that I have to activate it ...
0
votes
1answer
2k views

How to configure Firewall

How can I configure firewall for what I use as a web development server. I should be blocking all ports except 80 (HTTP), FTP, SSH? I tried configuring using ufw, gufw, firestarter but I ended up ...