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

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Apache timeout, OK on localhost

I have been staring at this for 2 hours now and can't figure it out. My webserver was running fine until earlier today. But now it can't be accessed from the Internet. The server is apache2, but ...
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1answer
2k views

Can't delete an iptables chain

I'm having a problem on deleting a user-defined chain. these the are rules I entered. sudo iptables -t mangle -N internet sudo iptables -t mangle -A PREROUTING -i eth1 -p tcp -m tcp --dport 80 -j ...
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1answer
72 views

after software update, website not accessible

I just applied a bunch of recommended updates this morning (which seems to have upgraded the kernel to 3.8.0-32.47), and suddenly I cannot connect to the machine on port 80 (http) or 22 (ssh). Ping ...
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0answers
3k views

Ubuntu 12.04 LTS - vsftpd problem. No connection. Connection refused

i have a problem with vsftpd server running on Ubuntu 12.04 LTS. Here is the configuration: ubuntu Server address - 192.168.5.100 router address - 192.168.5.1 roger/# grep -v "#" /etc/vsftpd.conf ...
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0answers
138 views

found someone lurking in my LAN, not sure what to do next

I have DD WRT router with internal numbers all falling within 192.168.1.0/24. I was looking on my firewall records this morning and found someone at 10.10.109.100 got blocked from accessing port 5353 ...
4
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1answer
2k views

Ban IP by country in UFW

I want to block a country in my server, but I don't know which rule I must use in UFW (or iptables). For example, people from US and other countries can see the site, but visitors from Russia can't. ...
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1answer
894 views

UFW, allow from wlan to eth

I would like to use my ubuntu 12.04 notebook as a wifi hotsport to my smatphone. Everything is going ok, using dnsmasq and hostapd and allowing ports 68 and 53 on UFW. But to access the web the UFW ...
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1answer
789 views

What's the difference between -p tcp and -m tcp in iptables?

I just noticed an entry in /etc/sysconfig/iptables along the lines of -A INPUT -p tcp -m tcp --dport 138 -j DROP I am not so sure why there has to be two switches here for matching protocol TCP, ...
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1answer
8k views

How can I allow ssh connection from an IP subnet on port 10022 using iptables?

I need to set up a server with public IP for bandwidth testing, and I already have a script to drop all incoming traffic except for the ports I need. I have changed the ssh port from default (22) to ...
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2answers
2k 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 ...
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1answer
99 views

No matter what I researched and did I can't connect to my MySQL server

Ubuntu installed MySQL for me through LAMP. When I connect with SSH I can login with the root user but not the user i created myself. When I use HeidiSQL I can't login with anything. I ran these ...
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1answer
411 views

Understanding Iptables

iptables -A INPUT -m state --state NEW -m tcp -p tcp --dport 7000:7010 -j ACCEPT I trying to understand the -m state --state NEW part. Searching through the man pages and correct me if I am wrong ...
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63 views

Can a weak Ubuntu user password be a risk for ONLINE security?

Can anyone gain an unauthorized remote access to my Ubuntu machine? Does having a strong user password really helps prevent this? Or firewall just doesn't let anyone in by default, regardless of the ...
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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 ...
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1answer
870 views

Ubuntu Firewall: Apache only visible on lan

How can I add a rule to the Ubuntu firewall that makes Apache server only accessible from the internal LAN? ufw status ng@ng-laptop-kv:~$ sudo ufw status Estado: activo Hasta ...
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1answer
213 views

having problem with squidGuard. Need help [duplicate]

when i write down this command on my terminal for configuring squidguard squidGuard -d this error shows up squidGuard: error while loading shared libraries: libdb-4.6.so: cannot open shared object ...
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1answer
203 views

Issues with shorewall

I'm new to using Ubuntu OS and its interface and using terminal. Recently I was trying to deploy squid, and shorewall firewall. Even though shorewall is running I can't get through one command, i.e. ...
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1answer
155 views

iptables forwarding rule

I entered the following rule into my iptables: sudo iptables -t nat -A PREROUTING -p tcp --destination-port 80 -j REDIRECT --to-ports 1337 and then when I went to remove it, I couldn't find it ...
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1answer
2k views

Connecting to NAT virtualbox guest from bridged network

I've setup a Virtualbox Ubuntu 12.04 server using Vagrant. I can ssh to it and even ping my desktop from it. What doesn't work is to ping the guest OS from my desktop. I've tried to flush the ...
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1answer
497 views

UPNP - How to configure GUFW

I have a TP-LINK TD-W8968 router with a mediaserver (UPNP/DLNA) port. The port has a USB stick with media content. I can access this content via XBMC and Totem/Movie player without any hassle. But ...
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2answers
3k 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 ...
3
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1answer
172 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 ...
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1answer
2k 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
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1answer
4k 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 ...
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1answer
797 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 -- ...
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1answer
992 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 ...
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1answer
321 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 ...
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1answer
164 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 ...
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0answers
115 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 ...
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0answers
1k 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 ...
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0answers
271 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 ...
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0answers
992 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 ...
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1answer
163 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
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0answers
497 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 ...
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1answer
144 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
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1answer
4k 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 ...
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0answers
355 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
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1answer
494 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 ...
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1answer
405 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
2k 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] ...
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2answers
3k 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 ...
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0answers
189 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 ...
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2answers
27k 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: ...
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2answers
2k 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
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1answer
312 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 ...
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2answers
144 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, ...
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votes
1answer
6k views

How do I allow local IPv6 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 ...
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1answer
349 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 ...
1
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1answer
4k 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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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 ...