Tagged Questions

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

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1
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1answer
130 views

How to allow SSH from internet when it is forwarded to a non-standard port

I'm configuring a virtual firewall using Shorewall and have a rule to forward the external port 2222 to internal port 22: DNAT inet lan:192.168.1.2:22 tcp 2222 where 192.168.1.2 is the ...
0
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0answers
585 views

Manually turn off firewall/unblock ssh port

Ubuntu Server 12.10 Last night I was messing with ufw, so I can enable some ports on the machine. Little did I know I just blocked port 22. Hours later closing PuTTy, I tried to connect to the server ...
1
vote
1answer
222 views

Remote ACCESS - SSH listening port filtered out by Firewall?

I am trying to access a remote server, with no physical access. I have accidentally changed the previous listening port in SSH and forgot to change it in the firewall rules. In firewall 15000 is ...
0
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0answers
74 views

Configuring a strictly local dns server for local network media streaming

I am fairly new to Linux, but I have an Ubuntu media server set up in my house. We can't afford to have an internet connection, so I move the server back and forth occasionally when I need to run ...
0
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0answers
157 views

how to proxy to a VPN connected server with local services running?

I'm having trouble accessing services that are running on my Linux Box from outside the local network. The setup is not as simple as most tutorials describe so I'm a bit stuck. My Linux Box (running ...
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0answers
57 views

UFW problem : can not access certain pages

Hello, I configured iptables using ufw to deny traffic from and to anywhere except my chosen ports. This is my /lib/ufw/user.rules : *filter :ufw-user-input - [0:0] :ufw-user-output - [0:0] ...
0
votes
1answer
49 views

Trouble saving iptables

I am having some issues with removing an iptable entry I have entered. I added -A PREROUTING -d 95.211.213.149/32 -i venet0 -p tcp -m tcp --dport 443 -j REDIRECT --to-ports 1194 To experiment ...
1
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0answers
342 views

Squid proxy and firewall blocking HTTP requests

I have 3 virtual machines. One functions as a router. A HTTP server is installed on another machine. The third has to connect to the server via the router. I have installed a web proxy(Squid3) on the ...
0
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2answers
2k views

Open source stun turn server which can do hole punch is there similar packages?

Is there any open source stun/turn server which can do hole punch like numb for Ubuntu ? Numb is a STUN/TURN server. Description A STUN/TURN server is used for NAT traversal in VoIP. ...
2
votes
1answer
10k views

Where are iptables's rulesets stored on Ubuntu 12.04?

Ubuntu 12.04 LTS - iptables v1.4.12 TLDR: Where are iptables's rulesets saved when invoking iptables-save <ruleset-name> ? Explanation: According to this answer basic way of saving ...
0
votes
1answer
215 views

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 ...
0
votes
1answer
1k 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 ...
0
votes
1answer
66 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 ...
1
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0answers
2k 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 ...
2
votes
0answers
132 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 ...
1
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0answers
153 views

ubuntu server apf-firewall configuration

I have not used the apf-firewall before and I'm having trouble configuring it. I have already try setting the iptables but it fails to start, so what more do I need to do? thank you
4
votes
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. ...
0
votes
1answer
609 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 ...
0
votes
1answer
604 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, ...
2
votes
1answer
7k 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 ...
1
vote
2answers
1k 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
93 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 ...
1
vote
1answer
366 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 ...
1
vote
0answers
61 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 ...
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 ...
0
votes
1answer
675 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 ...
1
vote
1answer
181 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 ...
0
votes
1answer
149 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. ...
0
votes
1answer
122 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 ...
0
votes
1answer
1k 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 ...
1
vote
1answer
352 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 ...
2
votes
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
votes
1answer
128 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
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
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
714 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
830 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
283 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
110 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
113 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
vote
0answers
970 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
220 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
902 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
140 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
426 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
127 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
283 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
449 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
363 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 ...