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

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4
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4k 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 ...
3
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30 views

xrdb to Ubuntu machine not working from external network

I have a Ubuntu machine that I would like external users to connect to using RDP. Connecting from an internal network works perfectly fine. But users outside of my network,who use the public IP, can ...
3
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580 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
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0answers
397 views

Can't ssh into my home PC remotely

I have a computer at home running on 14.04. I would like to be able to send jobs to that computer (I will call it server) from my laptop (running on 15.04) and share files between the two. I am able ...
2
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0answers
78 views

How to know the all minimum privileges that software needs?

I am using a VPS as a public proxy, and I have begun to realize that I must make my VPS more secure as I have seen in Securing Public Shadowsocks Server. Shadowsocks is a fast tunnel proxy that helps ...
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165 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
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0answers
149 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 ...
2
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154 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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2k 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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428 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
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0answers
1k 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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210 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
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0answers
820 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
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0answers
286 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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86 views

Firewall configurator not opening after upgrade to 16.04

after upgrading to 16.04 the firewall configurator is not showing up any more. The firewall itself (UFW) seems to be running as: sudo ufw status returns active and my rules. running the GUI from ...
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0answers
28 views

How to block Internet access for some devices on given hours?

I have a Ubuntu machine (15.10) running as a gateway which routes / firewalls traffic between a LAN an Internet. I need to block Internet access during some hours for specific devices on the LAN. ...
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82 views

Why does remote SSH connection time out?

My server runs Ubuntu Server 14.04. When connecting over SSH from a local LAN client it works fine. When I connect using a different machine from an outside network, I get 'connection timed out'. I ...
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0answers
124 views

UFW is blocking “gvfsd-smb-browse” on changing ports

I have a problem connecting to the samba shares between two of my computers. One is a Laptop and the other a Destop-PC, both running Ubuntu-Gnome 15.10. It changes from which Computer I can connect to ...
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0answers
40 views

Allowing sshd on local network without access to internet

I have setup sshd on my server and can access it fine from both my local network and remotely from other networks. I set up port forwarding using a different port than port 22. Port forwarding is ...
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95 views

Vagrant NFS folders + Firewall rules

I am trying to configure the firewall -via the GUI tool- on 14.04 by adding rules to allow NFS folder sharing with my vagrant box. However this only works when the firewall is disabled as on vagrant ...
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111 views

What's the purpose of economy.canonical.com?

I noticed that in one of my server's /var/log/ufw.log this morning that the firewall had blocked the IP address 91.189.91.23 from accessing port 80. This occurred 9 times within about a minute and a ...
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75 views

How to configure FileZilla on xubuntu

I'm trying configuring FileZilla on Xubuntu latest version but at the end of the Wizard the message is: Connection with server got closed prematurely. Please ensure you have a stable internet ...
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0answers
89 views

Ubuntu machines cannot connect to each other on the same network

I'm having trouble with Ubuntu machines not cooperating on my home network. The network structure is VERY simple. It's simply two Ubuntu machines (one running XBMCbuntu on 14.04, the other Ubunutu ...
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115 views

regenerate iptables from “iptables -L”after disk failure

My system disk failed catastrophically. I've replaced and mostly restored the OS on a new disk but all I have for my iptables is the output from iptables -L. Is there a way to automatically recreate ...
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207 views

Ubuntu Port Scan , Security concerns

Scan results of my ubuntu 14.04 $ nmap 127.0.0.1 Starting Nmap 6.40 ( http://nmap.org ) at 2015-05-02 08:43 IST Nmap scan report for localhost (127.0.0.1) Host is up (0.0021s latency). Not shown: ...
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393 views

Why can't I connect to my localhost port from a remote computer?

I'm using link-grammar server to convert sentences into semantic graphs. It provides an API though a port to do the above process. It's configured to works through port 9000 of localhost. I used to ...
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0answers
42 views

UFW open range is still blocked

I have opened up a range of ports using UFW. The rules in question are shown below (output of sudo ufw status numbered). I have restarted UFW since I added the rule, yet in lnav I still see log ...
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0answers
90 views

Ubuntu as a bandwidth throttling box on windows network

I need to test the performance of some applications over different capacity connections (broadband, EFM, LAN extension etc). How would i configure an Ubuntu server to sit between the main network ...
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0answers
128 views

Transparent proxy listening on sub-interfaces

I have iptables and squid on the same box. HTTP traffic doesn't seem to be going through the transparent proxy when I change my rules on the filter table. What is the best point to filter http ...
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0answers
79 views

Is this ufw configuration correct?

I have to link my openstack private cloud on a cloud management platform online. The cloud location is on my private ip (192.168.0.9) , i can't use that ip since the platform need a public ip so i ...
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0answers
205 views

How to config PORT KNOCKING on CSF ubuntu server and access it by linux?

I'm trying to run port knocking work on a CSF on a small VPS, i setup this: 1 - the result of csf first test ok 2 - TCP_IN = "53,80" TCP_OUT = "53,80,113,443" UDP_IN = "53" UDP_OUT = "53,113,123" ...
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581 views

Why is ip forwarding not working in xubuntu 14?

I upgraded my gateway computer from xubuntu 12 to 14 and the computers on my home network lost their internet connection. I found that the upgrade had uninstalled my old firewall, Firestarter, and ...
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0answers
133 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
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0answers
162 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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0answers
515 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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0answers
132 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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0answers
69 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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0answers
487 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
2k 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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0answers
109 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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0answers
304 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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0answers
137 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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0answers
8k 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 ...
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0answers
207 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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0answers
96 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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0answers
4k 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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639 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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0answers
554 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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0answers
1k 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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0answers
354 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 ...