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

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3
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1answer
100 views

UFW python documentation

I'm trying to access ufw with python, but on line 53 of backend.py, they raise a weird error that makes no sense: Traceback (most recent call last): File "mymodule.py", line 1467, in ...
0
votes
1answer
1k views

How to make ubuntu gateway?

i am new on Ubuntu. i want to make a gateway. i have some 25 systems and switch but i don't have any server. i want to setup a system as a gateway system and want to make a firewall. i want that ...
2
votes
1answer
3k views

Apache (and other services) work on localhost, but not IP address

My Apache server is working correctly on port 80. When I try to enable SSL on port 443, I can connect via localhost (telnet localhost 443) but not via IP address (telnet xxx.xxx.xxx.xxx 443). To ...
4
votes
1answer
608 views

Why ufw is blocking my outgoing traffic?

Here is my status: $ sudo ufw status verbose Status: active Logging: on (medium) Default: deny (incoming), allow (outgoing) New profiles: skip To Action From -- ...
1
vote
1answer
689 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 ...
0
votes
1answer
238 views

Screen Sharing Behind Firewall

I've setup my brother's computer with Ubuntu. I would like to be able to control his screen with his permission, to configure and instruct him when needed. However, he is on a provide IP provided by ...
1
vote
1answer
80 views

How does ufw handle conflicting rules?

I recently had the following conflicting rules on ufw 445/tcp ALLOW 192.168.1.0/24 445 DENY anywhere 445 DENY anywhere IPV6 ...
0
votes
0answers
111 views

Help with ssh between machines on local network [duplicate]

I have two machines on my local network (both with Ubuntu 10.04) and I want to ssh (and rsync) between them. The two machines have fixed IPs 192.168.0.15 and ...17 Both computers frequently ssh ...
1
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0answers
767 views

SSH connections rejected after UFW allow 22

I am trying to setup UFW on a 12.04 server. SSH works great with UFW off. Setting root@ugvps:~# ufw enable Firewall is active and enabled on system startup root@ugvps:~# ufw status Status: active ...
2
votes
0answers
149 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
832 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
1answer
125 views

How do you install and configure TuxGuardian in Ubuntu 12.04?

Can anyone guide me on the process to install TuxGuardian in Ubuntu 12.04? Its a freeware application available at: http://tuxguardian.sourceforge.net
1
vote
0answers
363 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 ...
1
vote
1answer
110 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 ...
0
votes
1answer
3k views

Postfix is timed out while sending

I have just set up postfix (with tasksel install mail-server) with the default settings. Unfortunately, I can not send e-mails from by SMTP server. Here is my main.cf: # See ...
1
vote
0answers
237 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
391 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 ...
0
votes
1answer
324 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
1k views

Cannot open port

I've been struggling to open the port 5432 for remote PostgreSQL access. Which I installed on a Ubuntu 10.04 desktop machine. Here is the shell log: xybrek@ubuntu:~$ sudo ufw allow 5432 [sudo] ...
1
vote
0answers
64 views

Can not permanently clear iptable rules

I use the following commands to flush all iptable rules: sudo iptables -F sudo iptables -X sudo iptables -t nat -F sudo iptables -t nat -X sudo iptables -t mangle -F sudo iptables -t mangle -X sudo ...
3
votes
2answers
2k views

Why is ufw logging 'BLOCK' messages regarding a port for which ufw is configured to 'ALLOW' connections?

Here's an example log message: May 25 10:36:07 myserver kernel: [7057243.392334] [UFW BLOCK] IN=eth0 OUT= MAC=00:02:55:67:82:eb:00:06:b1:3a:ef:62:08:00 SRC=69.197.128.26 DST=192.168.100.101 LEN=44 ...
2
votes
0answers
167 views

How should I configure Ubuntu firewall?

Just discovered Gufw, and I'd like to set it up. But I haven't found any documentation telling me what I should/should not allow. I'd like to be able to use it but the only documentation on the web ...
0
votes
2answers
18k views

SSH connection refused when connecting remotly

I set up my Ubuntu server and it can connect to itself when running ssh localhost. However, when I run Putty on windows 8 I get a "connection refused" error. I have, to the best of my ability: ...
1
vote
2answers
1k views

ufw firewall operation

I have always run the program UFW as my firewall in Ubuntu, and been satisifed with its performance. When I installed Ubuntu 13.04, and enabled ufw, I was not able to access the internet, and all ...
2
votes
1answer
226 views

Open ports for development purposes

I'm doing some Java ME Development in my brand-new Ubuntu laptop, coming from a now replaced Windows Vista one. What I'm trying to do is run a Mobile Simulator that acts as an HTTP Server -receives ...
0
votes
2answers
132 views

If I have Ubuntu installed along side Windows, does the firewall on Windows work along with the antivirus system?

I have Ubuntu installed on my Windows 7 computer. I was curious to know if the firewall on that one is activated (I have to turn it on each time I'm on the computer) along with the antivirus system, ...
2
votes
1answer
3k views

How do I allow local subnets in ufw?

I recently got IPv6 connectivity at home and now I would like to allow connections to my home server via IPv6 from the LAN only. The trick is that the IPv6 address/prefix assigned to the server is ...
1
vote
1answer
230 views

Unable to connect through Java programs in Ubuntu

I am unable to connect to any host through Java programs, getting java.net.ConnectException: Connection refused. Does it have anything to do with Ubuntu firewall configurations or any other ...
0
votes
1answer
2k 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?
20
votes
3answers
929 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 ...
3
votes
2answers
4k 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 ...
0
votes
1answer
770 views

How do I configure ufw to only allow outgoing/established connections for a IPv6 network?

How do I configure ufw to only allow outgoing/established connections for a IPv6 network? I am using an old computer with 12.04 installed to create an IPv6 router for my local network. I would like ...
1
vote
1answer
434 views

Setup firewall: ask user to allow new incoming/outgoing traffic?

I'm using Ubuntu 12.10 and as I know there is already a firewall on any ubuntu system. It's ufw and because I like fancy gui stuff I can use gufw, that's very nice. Now I would like to configure this ...
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 ...
0
votes
1answer
289 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
119 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.).
7
votes
1answer
6k 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 ...
5
votes
2answers
952 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 ...
2
votes
0answers
478 views

How I can connect the syslog-ng with a mysql database?

Hi guys I want to use a syslog-ng server for logging data from the firewall and I get Data from the Firewall in the file /var/firewall.log but now I want that the logs go to a database. For this I ...
0
votes
1answer
825 views

How do I firewall my computer so that only traffic go through the VPN?

I have read "How to configure an Ubuntu server so that all traffic goes through a VPN?" and found it doesn't apply to my case. I am only interested in the client-side of the VPN connection as I am a ...
2
votes
2answers
818 views

All ports are closed until they are opened manually by the user? Is it true?

I am new to Linux and Ubuntu. I googled and read some articles stating that all ports are closed until they are opened manually by the user. Is it correct? And what do you mean by "listening on a ...
1
vote
2answers
1k views

Firefox cannot find website servers, what is wrong?

Recently, I tried to access the internet using Firefox. I have a good wifi signal according to the toolbar at the top, but Firefox says "Firefox can't find the server atwww.example.com." I tried ...
1
vote
1answer
816 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
266 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 ...
5
votes
4answers
430 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 ...
0
votes
2answers
462 views

Updating 10.10 to the latest version through a firewall [duplicate]

I've had Ubuntu 10.10 on my server since I bought it several years back. I've tried to upgrade in the past but I'm always thwarted by my company's firewall. I receive messages like these: W:Failed to ...
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 ?
1
vote
1answer
463 views

using proxy with online flash games

when I try to play this flash online game "tankionline.com" using our university proxy I get this error "Cannot establish connection (host: 62.152.57.11, ports: 4444,5190,5223,5222,5050)". In windows ...
0
votes
1answer
243 views

block outgoing internet calls from inside a container

This question is not similar to my earlier post. This is pretty simple I think, I just don't know enough about networking and the ubuntu firewall. I followed this article and setup a linux container ...
3
votes
3answers
5k 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 ...