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

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340 views

Where to get nftables?

As far as I understand the kernel facility nftables exists in the kernel that comes with Ubuntu 14.04. As is proven by the following two commands: # grep -E '(NF_TABLES|NFT_)' /boot/config-$(uname ...
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154 views

UFW is DENY/DENY, but PACKETS are still getting out of my ethernet device. Why is this?

Hello, I have a question. I would like to use the UFW Ubuntu Firewall to lock both Input and Output completely from the server to ensure no packets are sent initially as a baseline. I enabled UFW, ...
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123 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 ...
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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 ...
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831 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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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 ...
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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 ...
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244 views

Why is SSH not accessible after installing KDE on Ubuntu Server?

I installed KDE onto my Ubuntu server, which is operating as a file server. It installed a firewall that wasn't there previously. I can't reach any of the services I had operating on the box now, ...
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22 views

how to block all tcp and udp and other protocol and only allow layer 2 communication?

sudo ufw disable sudo ufw default deny sudo ufw allow XXXX sudo ufw enable Does sudo ufw disable block layer 2 by default? How to block all TCP, UDP and other protocols, so only layer 2 ...
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46 views

Why aren't these ufw rules working?

I'm trying to configure ufw to only allow connections to 3 ip addresses on my local network, and deny everything else. Here's the commands I'm using: yes | sudo ufw reset sudo ufw default deny sudo ...
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34 views

Ubuntu Randomly Rejecting Hosts

currently I am facing a very strange problem: my Ubuntu is randomly resetting connections and I have no clue why. /etc/hosts.deny is empty (resp. just the default file with comments only, that comes ...
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33 views

Connecting to Ubuntu host not possible

I have an Ubuntu-Host which is connected via wlan (and for testing to wired net) to a local net. This Ubuntu-Host is not reachable via network by any other clients on the same network. But: If I do a ...
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155 views

Ubuntu UFW init failure

I have some strange UFW behaviour. Whenever I install it cleanly and add some allowed ports to it (without restarting) it works great. But when I restart UFW or the whole server for the first time ...
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33 views

Dynamically Enable LAN traffic in Firewalld (using profiles in network-manager)

I am trying to use firewalld to allow dynamic profiles for different connections in Network Manager. When I'm at home, however, I would like to allow anything coming in on the LAN (local subnet). I ...
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39 views

Ubuntu server periodically unreachable

I have an Ubuntu Server 14.04 server running. The server has two NICs and acts as a NAT router, with the help of shorewall. Shorewall also acts as a plain firewall for blocking ports that I don't want ...
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69 views

Port forwarding out multiple VLAN interfaces that have same IP address

So I have an Ubuntu machine with multiple VLAN on an interface eth1 and each VLAN has the same IP address (172.16.0.2). I need to be able to simultaneously telnet into a rack of devices that are also ...
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33 views

Firewall rule to drop DOS attacks. What is wrong with my command?

I have a script like that : MAXREQ='cat /var/log/maxreq_tmp' DE=6 iptables -F iptables -I INPUT -p tcp -m state --state NEW -m recent --set iptables -I INPUT -p tcp -m state --state NEW -m recent ...
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42 views

Can't access Flask from local network

I've already read this thread, but it is not what I'm looking for. I'm running Flask on Ubuntu 13.10 with this configuration, but I can't access it from the local network using the correct ip and port ...
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47 views

Cannot connect to work VPN

I'm using Ubuntu Studio 13.04 Saucy, and generally new to Ubuntu. I work for a company which provides Windows based pptp VPN access for working remotely. Soon after I installed Ubuntu Studio, I was ...
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159 views

UFW, IPv6, and HTTPS

I'm running Kubuntu 13.10. I recently enabled IPv6, and setup UFW to support it. Everything seems to be working as expected, except I've noticed certain traffic being blocked with an AUDIT-INVALID ...
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89 views

Configuring ufw and iPredator VPN

I am running a VPN via IPredator on Ubuntu 12.04 Desktop, which works perfectly, when ufw is disabled. When I enable ufw, I logically cannot establish a connection. IPredator states that I have to ...
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77 views

Allow users to access specified IPs only

I have a computer that offers both a VPN and a SSH server running three (separated) VPN networks. All users log into the server via ssh. However, I want that only certain users can communicate to ...
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299 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 ...
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1k 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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144 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
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47 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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766 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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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 ...
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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 ...
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63 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 ...
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0answers
93 views

Is there a firewall that blocks a process and shows a dialog with buttons Allow, Drop, Disable?

Currently I use ufw and Firestarter, and I'm just learning how to use a firewall. When I used windows there were a couple of firewalls that could block a process which tried to establish connection ...
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69 views

How to load firewall before network?

How can I ensure iptables gets up before any network adapter gets up? And can network be stopped to be brought up if there is an error in the firewall rules? For exiting and future network adapters. ...
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603 views

How to change Port 27000 from filtered to open status

In my ubuntu box I am running flexlm licensing software on port 27000 and I am able to pull the license from the this port to run the simulation software locally. I am also trying to run the same ...
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160 views

ssh client times out to some servers, works on others

I have a strange problem and I'm not sure where to begin. My ssh client works on some servers but times out on others. Obviously, I checked that the servers are accessible via ssh from other ...
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0answers
491 views

Firewall stopped and disabled on system startup ERROR: problem running ufw-init

I am trying to set a VPN server on my PC (Ubuntu). I am following a tutorial , http://cviorel.easyblog.ro/2009/02/09/how-to-set-up-a-vpn-server-on-ubuntu/. I made changes in various files including ...
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20 views

Ethernet connection blocks some traffic while wifi works flawlessly

I'm not sure whether it's related, but I recently tried to reroute inbound traffic from a user-accessible port to port 80 following these instructions: http://serverfault.com/a/112798 Now, I can't ...
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0answers
9 views

Allowing web site through shorewall firewall

I'm fairly new to Linux and I've been following some guides to get a web server up and running. So far all is well with the web server and accessing it from the net. I've installed Shorewall firewall ...
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0answers
18 views

Can't find Printer in the Printing program Officejet 6500

I have the following problem: I can't find my HP Officejet 6500 Pro to connect it with my Ubuntu 12.04 laptop. Before it worked perfectly, but since I use an extra router I cant connect to my printer ...
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18 views

Firewall router

Ok I throw in the towel. Before posting I ran read untold website forums / examples, tried lots of commands so please don’t say ‘Google is your friend’  I want to setup an Ubuntu virtual pc as a ...
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0answers
86 views

Creating routes using iptables in ubuntu 14.04

I'm a newbie at ubuntu's administration although I've been using linux for a while just at user level. Let's show my problem. This is my network (only static IP addresses are used, for both private ...
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0answers
45 views

Unable to connect to Chromecast

I seem to be having a problem connecting to Chromecast from Ubuntu. Unlike the question How can I use Chromecast, the issue doesn't seem to be firewall related. I have already tried opening the ports ...
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49 views

iptables rules keep showing up

I just installed an ubuntu precise server, after a few weird communications issues I checked the iptables list and found: Chain INPUT (policy DROP) target prot opt source ...
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30 views

ufw is not working properly

I'm trying to enable ufw in remote ubuntu server. This server has two LXC container running. One container has nginx server running and I have hosted web application, right now every thing is working ...
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0answers
41 views

Ubuntu 13.10 allows connections from LAN but not from outside LAN

SSH ports configured to all 22 and another one. I can connect from another Linux/Windows workstations on my home LAN no problem. Same thing for nomachines nx server. Teamviewer connects with no ...
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0answers
16 views

Ubuntu 12.10 won't boot: FIREWALL: IN=wlan0 OUT= MAC=… SRC=… DST=… LEN=68 TOS=0x00 PREC=0x00

My 12.10 won't boot up suddenly. And it just stucks at the following screens: I've tried googling "Ubuntu 12.10 boot stuck at FIREWALL ...", but had no luck (most of the results are not ...
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47 views

can't allow a specific IP in ufw

I've just got myself a VPS and am completely new to running a server. I've installed ufw as I only want to allow access to it from one particular domain hosted on another server. I've read the ...
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37 views

Connection timed out on specific ports

We have an apache server running couchdb on port 5985 (not 5984). On my computer, I have Windows 7 and Ubuntu 14 LTS. From Ubuntu, I can connect to the host via http://example.server.domain, but I ...
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0answers
36 views

Synergy works one way only?

I am running two Ubuntu 12.04 machines connected to the university network. One is a desktop and the other a X230t Lenovo laptop. They are both wired(eth0) to the same network. I am trying to get ...
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0answers
63 views

Using Gufw create rule to reject traffic from specific subnet

I am connected to two networks one trusted, one not. Untrusted range is 172.18.0.0/16. (I need some connectivity with it, but not all ports open.) I would like to setup Gufw to reject connections on ...
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0answers
70 views

Setting up a firewall Ubuntu Server 13.10 to specified domain users of a Windows server 2008

So, here's the plan: I want to set up a firewall that allows/blocks certain websites for specified users in a Windows server domain (local); For example: For the user domain.name/user1 I want to ...