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

learn more… | top users | synonyms

2
votes
0answers
24 views

How do I find which OS layer (iptables, rp_filter, etc) is dropping a packet?

Let's say that I'm running a ping towards a machine and I see from tcpdump that the icmp echo reply is being received at the ethernet port but the ping program is not getting it. So I know that ...
2
votes
0answers
167 views

Refused connection of ssh

I installed openssh on my new Ubuntu14.04 server, turned on ssh, and enjoyed it after I finished installation. Every thing was fine; however, after just one night, I was blocked when using putty as ...
2
votes
0answers
243 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, ...
2
votes
0answers
129 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 ...
2
votes
0answers
178 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
892 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 ...
2
votes
0answers
175 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 ...
2
votes
0answers
567 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 ...
2
votes
0answers
252 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, ...
1
vote
0answers
68 views

Can't Connect to Apache2 Server From External Device (in LAN) Nor From External IP?

I forwarded ports 80 and 443 for my apache 2 server. However, if I: try connecting to the server via external IP or try connecting to the server from a local device via my local ip, I cannot gain ...
1
vote
0answers
45 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 ...
1
vote
0answers
113 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 ...
1
vote
0answers
46 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 ...
1
vote
0answers
42 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 ...
1
vote
0answers
404 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 ...
1
vote
0answers
60 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 ...
1
vote
0answers
63 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 ...
1
vote
0answers
140 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 ...
1
vote
0answers
52 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 ...
1
vote
0answers
66 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 ...
1
vote
0answers
6k views

ubuntu 14.04 default firewall rules

I would like to know exactly which scripts are responsible for default iptables rules (no ufw, no gufw) in Ubuntu Server 14.04. After fresh installation even with ufw disabled (by default) there are ...
1
vote
0answers
53 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 ...
1
vote
0answers
203 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 ...
1
vote
0answers
108 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 ...
1
vote
0answers
84 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 ...
1
vote
0answers
328 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 ...
1
vote
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 ...
1
vote
0answers
150 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
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 ...
1
vote
0answers
917 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 ...
1
vote
0answers
398 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
0answers
263 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 ...
1
vote
0answers
72 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 ...
1
vote
0answers
95 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 ...
1
vote
0answers
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. ...
1
vote
0answers
683 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 ...
1
vote
0answers
184 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 ...
1
vote
0answers
516 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 ...
0
votes
0answers
9 views

3.13.0-37-generic basic router repeatable issue - packet loss

I have two desktop PCs and I wish to use them as a simple router between two LAN segments. I am not using NAT, SNAT, DNAT, and all my iptables tables/chains policy are ACCEPT. With iptables wide open ...
0
votes
0answers
8 views

Make Proxy Server with arno-iptables-firewall

I am trying to configure arno-iptables-firewall to work with transparent squid but no success. browsing is ok using local configured proxy on the computer but can make the arno-iptables-firewall to ...
0
votes
0answers
11 views

If I turn on the Firewall I cannot connect to the internet

I run GUFW but even on any setting I cannot access the internet if its turned on. Why would this be? I also noticed in the "Listening" box that theres a lot of info going on which I don't understand ...
0
votes
0answers
9 views

Blocking time in request resources

I have this problem in my Ubuntu server 12.04.4: My page is loading too slow, and watching the NET tab from the firebug I can see many blocking time for all requests. There is some way to ...
0
votes
0answers
79 views

UFW for OpenVPN

I want to configure ufw (uncomplicated firewall) for OpenVPN. Connections are only allowed through OpenVPN. Everything else should be blocked. So if OpenVPN is disconnected -> no internet! I found ...
0
votes
0answers
44 views

how to install mod_security apache2.4

I was looking at my logs yesterday, when I saw a bot roaming folders I have in my robots.txt file. I tried to block it with a rule in my UFW firewall, but this did not keep them out. So then I was ...
0
votes
0answers
9 views

Multiple rate limits in ufw

I have set two rate limits in ufw: In summary: limit http to 120 requests in 60 seconds; and 600 requests in 600 seconds -A ufw-user-input -p tcp --dport 80 -m state --state NEW -m recent --set -A ...
0
votes
0answers
59 views

Ubuntu Server 14.04: Configuring ConfigServer Security & Firewall for Mediatomb

I am currently have issues with getting Mediatomb to work with CSF on my home network server. I have been able to get the Mediatomb server to work with CSF turned off. My Mediatomb web GUI is set to ...
0
votes
0answers
34 views

Shows :::18332 instead of 0.0.0.0:8332, what means that?

What means ::: in front of a port (where usually the IP should be) when doing netstat? It shows :::18332 instead of 0.0.0.0:18332 and I can't connect to that port from the outside. This is for ...
0
votes
0answers
13 views

webstorm website connecting remotely

I am new to Ubuntu and to webstorm so please bare with me if its very basic question. I am trying to connect to the website run by webstorm on Ubuntu from Windows 8.1 PC ...
0
votes
0answers
36 views

UFW behind a router blocks traffic from the outside world

I'm seeing [UFW BLOCK] entries in my logs, where SRC=173.194.67.16 DST=192.168.1.2. My box is behind a router, DST is my internal IP, SRC seems to some Google server and I don't understand how is it ...
0
votes
0answers
90 views

vino-server: local connection works but not remote connection

I would like to remotely take control over ma grandma's PC, where I installed lubundu 14.04.1. This is not a duplicate of this other question (I want to avoid teamviewer + see below). I configured ...