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

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49
votes
7answers
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 ?
33
votes
4answers
11k 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.
23
votes
9answers
15k 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 ...
20
votes
3answers
1k 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 ...
18
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 ...
17
votes
3answers
62k views

How do I see which ports are open? [duplicate]

I am running a web server on a machine with Ubuntu 11. Everything is accessible from the local network, but not from outside. What can I do to check to make sure the appropriate ports are open? I am ...
16
votes
8answers
7k 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 ...
14
votes
6answers
4k views

Does spyware exist for ubuntu?

Someone I know said he had put spyware on my computer. Is he talking crap? I've been using Ubuntu 12.04 for nearly 3 years now and I've never seen any type of spyware, remote keyloggers or RATS ...
14
votes
3answers
125k views

How do I turn off the firewall in Ubuntu 12.04?

How do I turn off the firewall in Ubuntu 12.04? Thanks for the answers. The reason for turning it off was twofold: I often cannot make a wireless connectin to internet and get the server is unable to ...
12
votes
8answers
3k views

Is a Firewall really necessary these days? [closed]

should I install something like gufw?
11
votes
4answers
7k views

See configured rules even when inactive

I'm wondering if it's possible to get UFW to list the configured firewall rules even when it's not enabled. I only have ssh access to the server at this time, and I don't want to enable UFW if there's ...
11
votes
3answers
48k views

How do I know if my firewall is on?

I installed Firestarter, and configured my firewall. But I'm in doubt : On boot, I sometimes see a [FAIL] marker, and to the left, I guess it was something like "start firewall". I can't be sure ...
11
votes
4answers
16k views

How can I block ping requests with IPTables?

and stealth specific ports?
10
votes
3answers
20k 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 ...
10
votes
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 ...
9
votes
1answer
21k views

What are ICMP redirects and should they be blocked?

After enabling ufw and the Tiger security auditor, I see warnings saying: The system accepts ICMP redirection messages What are ICMP redirection messages? Should they be disabled for security ...
9
votes
1answer
831 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 ...
8
votes
2answers
6k views

How to set up an Ubuntu 10.04 machine to accept ssh requests only from within the local network?

I am about to install 10.04 (from bare metal to replace 9.04) and I want to set it up so that I can shh into the machine, but only from other machines on my local network. (I.e., I want to reject all ...
8
votes
1answer
9k 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 ...
8
votes
2answers
9k 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).
8
votes
3answers
1k views

Can I be notified about blocked connection attempts?

My computer is running Ubuntu 10.10 and I would like to know if there is a firewall that actively informs me when a certain program is trying to access the internet or when a connection attempt is ...
8
votes
3answers
23k views

How to enable ufw firewall to allow icmp response?

I have a series of Ubuntu 10.04 servers and each one has ufw firewall enabled. I have allowed port 22 (for SSH) and 80 (if it's a webserver). My question is that I am trying to enable icmp echo ...
7
votes
4answers
15k 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 ...
7
votes
1answer
348 views

Why are certain things able to get through ufw firewall?

I should say up-front that I am TOTALLY new to Linux, Ubuntu, and the technical side of networking. I am setting up Ubuntu on a server computer and have learned a bit about configuring the ufw ...
7
votes
2answers
3k 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 ...
7
votes
1answer
538 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 ...
7
votes
2answers
5k views

What do UFW's audit log entries mean?

I'm sometimes getting a lot of these AUDIT log entries in ... [UFW AUDIT] IN= OUT=eth0 SRC=176.58.105.134 DST=194.238.48.2 LEN=76 TOS=0x10 PREC=0x00 TTL=64 ID=32137 DF PROTO=UDP SPT=36231 DPT=123 ...
7
votes
4answers
2k 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 ...
6
votes
6answers
5k 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 ...
6
votes
1answer
10k 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
1k 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 ...
6
votes
2answers
5k 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
6
votes
6answers
2k 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 ...
6
votes
1answer
337 views

Securing Riak using Shorewall Firewall

I want to set up a Riak Cluster for a Web project. However, I want to secure this cluster so that only My Web Server(s) can access Riak Cluster. Basically, I will have one or more Web Servers and 4 ...
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 ...
5
votes
2answers
307 views

Is portfowarding to my localhost on my personal Ubuntu computer secure?

After installing Lamp on my personally Ubuntu computer, I am running a application that requires to connect to the web and send SMTP mail; for example paypal needs a www address to notify successful ...
5
votes
2answers
984 views

Ubuntu comes with firewall by default?

I understand the Ubuntu comes with firwallul UFW is true? There is a GUI for it? if so, what is his name and where do I download? It is possible that UFW notify us (like in windows with a pop-up ...
5
votes
2answers
1k views

Is it possible to block a webpage using ufw?

basically I have two machines X and Y. I want to block "http:// <IP-of-Y-Here> /AFolder/" from machine X on HTTP port 80 using ufw. Trivially, this can be completed (awfully) using ufw ...
5
votes
4answers
478 views

How to protect Ubuntu12.10 from Viruses, Spywares, Spamware and Intruders?

I have been using Windows OS for a long time and there i needed to install a separate Anti virus Program (included with firewall, anti spam) etc.. With my mentor's recommendation, I have replaced ...
5
votes
2answers
2k views

What does this UFW log mean?

CC-02 kernel [ 399.656733] [UFW BLOCK] IN=eth0 OUT= MAC= SRC=192.168.2.11 DST=192.168.2.22 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=14158 DF PROTO=TCP SPT=47368 DPT=22 WINDOW=5840 RES=0x00 SYN URGP=0 ...
5
votes
1answer
219 views

How do I accept inbound connections for a specific program?

Windows firewall allows to specify a program that will accept inbound connections no matter on which port(s) is listening (instead of specifying the port(s) to allow for that program). Is this ...
4
votes
3answers
7k 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 ...
4
votes
3answers
6k views

How can I open a range of ports in ubuntu using (g)ufw for use with membase?

I have membase (membase.org) installed and I have to open a bunch of ports in order for the cluster to function Adding the single ports was easy enough but I can't work out how to open the range ...
4
votes
2answers
725 views

What additional security measures should I apply for Ubuntu?

So on my Windows 7 install, I've got multiple free malware/virus scanners and a firewall up. But I've heard that Ubuntu (or Linux in general) is much more secure by default. So what additional ...
4
votes
3answers
3k views

Firewall Settings for Personal File Sharing

I have ufw set up to allow samba connections, but this does not seem to allow files to be transferred through Ubuntu's "Personal File Sharing" using the Public folder. The share can be seen, but not ...
4
votes
2answers
672 views

UFW rules don't work with docker

I have a 12.04.4 server, and I have enabled ufw, and have tried to block port 8080. However, it is still open. $ sudo ufw deny 8080 Rule added Rule added (v6) $ sudo ufw status numbered Status: ...
4
votes
2answers
5k views

What could be the cause for these strange UFW block entries in my syslog?

I've recently noticed a large number of recurring UFW blocks in my syslog. This surprised me as I have no UFW rules set: $ sudo ufw status verbose Status: active Logging: on (low) Default: deny ...
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 ...
4
votes
1answer
464 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 ...
4
votes
1answer
319 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 ...