Uncomplicated Firewall (ufw)

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4
votes
2answers
2k 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 ...
1
vote
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 ...
3
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 ...
1
vote
1answer
3k 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?
4
votes
2answers
6k views

What could be the cause for these strange UFW block entries in my syslog?

I've recently noticed a large number of recurring UFW blocks in my syslog. This surprised me as I have no UFW rules set: $ sudo ufw status verbose Status: active Logging: on (low) Default: deny ...
0
votes
1answer
943 views

How do I configure ufw to only allow outgoing/established connections for a IPv6 network?

How do I configure ufw to only allow outgoing/established connections for a IPv6 network? I am using an old computer with 12.04 installed to create an IPv6 router for my local network. I would like ...
1
vote
1answer
482 views

Setup firewall: ask user to allow new incoming/outgoing traffic?

I'm using Ubuntu 12.10 and as I know there is already a firewall on any ubuntu system. It's ufw and because I like fancy gui stuff I can use gufw, that's very nice. Now I would like to configure this ...
5
votes
1answer
4k views

Can I uninstall UFW completely?

I need to configure iptables manually and save and restore the rules using iptables-persistent package. so I don't want ufw anymore. I can simply disable it. but many chains are exists in iptables ...
2
votes
2answers
1k views

How can I cancel all the current communication from particular IP in Ubuntu 12.04?

I am working on Ubuntu 12.04 firewall. I want to deny any IP on runtime. I am using "ufw deny from IP". It's working for future connections. But it is not cancelling the existing connections like ssh. ...
3
votes
0answers
411 views

What do these lines in the UFW logfile mean?

These lines are repeated several times, first one at the time when remote ssh connection with the machine is lost (mac address is the address of eth used for Internet connection) Mar 24 21:20:32 ...
5
votes
2answers
1k views

Is it possible to block a webpage using ufw?

basically I have two machines X and Y. I want to block "http:// <IP-of-Y-Here> /AFolder/" from machine X on HTTP port 80 using ufw. Trivially, this can be completed (awfully) using ufw ...
2
votes
0answers
294 views

Why does UFW seem to slow down wordpress?

I have a speedy install of wordpress going on ubuntu 12.04. Everytime i enable the UFW firewall, things can get really slow. Sometimes fast, sometimes slow, intermittently. Logging on through ssh ...
2
votes
2answers
2k views

firewall ufw is “enable and active” but gufw is off

question concerning the ufw firewall : sudo ufw enable returns Firewall is active and enabled on system startup sounds fine, but when i start gufw after reboot, it is still off what does that ...
0
votes
2answers
2k views

Problems allowing outgoing multicast in ufw

I am having problems configuring the uncomplicated firewall (ufw) to allow outgoing multicast traffic. I am blocking all in and outgoing connections as the default policy. I have supplemented with the ...
1
vote
1answer
177 views

User to access only to specific IP addresses

How can I setup Ubuntu box so logged user can access only to several IP addresses, on all protocols? Additional problem is that Ubuntu uses proxy to acceess to internet. Tried with UFW, but did not ...
0
votes
1answer
671 views

Can't open a port

I need to run an app on my computer which connects to local port 49100. So everything runs on one computer. I tried adding rules to gufw, firestarter, manually: sudo iptables -A INPUT -p tcp --dport ...
1
vote
1answer
863 views

Regarding ufw firewall

I am using Gproxy software in my computer(Ubuntu 12.10). I want to allow incoming connection from only one IP adress,so that he can use internet. what settings should I configure in ufw firewall.
2
votes
1answer
235 views

Using Ubuntu as a gateway for monitoring and possibly IPS IDS within Active Directory

Ok, I've searched for days, maybe you can point me in the right direction. I have an MPLS scenario with a shared gateway in a multi-domain M$FT AD environment. On the inside of the MPLS all of the ...
1
vote
1answer
773 views

ufw configuration nat ppp0

please some tips how i can allow this request in ufw: [UFW BLOCK] IN=ppp0 OUT=eth0 MAC= SRC=10.11.22.2 DST=8.8.4.4 LEN=71 TOS=0x00 PREC=0x00 TTL=127 ID=52 PROTO=UDP SPT=59405 DPT=53 LEN=51 i tried ...
1
vote
0answers
181 views

Ubuntu all versions from 10.04 till 12.10 [closed]

Is simply enabling the firewall ufw (sudo ufw enable) sufficient enough for protection of the OS ? I mean should extra rules be added for 'better' protection, or is simply enabling the firewall enough ...
1
vote
2answers
1k views

UFW not allowing Transmission to transfer

I have set the rules in ufw for Transmission but when I try to use it it will not transfer and it also says the port is closed when checked under preferences. If I turn the UFW firewall off it still ...
0
votes
0answers
2k views

IP forwarding not working in Ubuntu 12.04 Server [on hold]

I'm having trouble getting IP forwarding going in Ubuntu 12.04 server with UFW. I'm trying to get OpenVPN working. I have two interfaces, eth0 and tun0, and they can't ping each other. I've made the ...
0
votes
1answer
4k views

Port listening on localhost:8000 but not on ip:8000

Hello I'm running a web application on port 8000. When I access it from the host server localhost:8000 it responds ok, 127.0.0.1:8000 also works, but 192.168.1.7:8000 does not work. 192.168.1.7 is the ...
4
votes
1answer
9k views

Why I'm getting this [UFW BLOCK] in my syslogs?

I wonder why I get this error on my syslogs: [7732763.396193] [UFW BLOCK] IN=eth0 OUT= MAC=02:8b:1a:75:d5:7b:02:8b:1a:40:00:03:08:00 SRC=x.x.x.x DST=x.x.x.x LEN=40 TOS=0x00 PREC=0x00 TTL=64 ID=53703 ...
2
votes
1answer
3k views

How do I configure ufw to allow ssh on another port? [closed]

I'm having some difficulties at the moment with my Ubuntu SSH server. The only title I could come up with summarizing my situation was too long so here is my problem: I recently discovered the ...
3
votes
2answers
10k views

How to configure UFW to allow IP Forwarding?

I have UFW, OpenVPN and Virtualbox installed on my home server. I have a host-only network for my virtual machine guests (vboxnet0) set up with the IP range 10.0.1.0, and another IP range of 10.0.0.0 ...
6
votes
1answer
2k views

Block Ping from a specific IP

I am on a private LAN 192.168.1.0/24. My ip is 192.168.1.3, I want to block only ping requests from 192.168.1.2. I am running ubuntu 11.10. I found two links First tells how to block an IP but not ...
3
votes
2answers
452 views

If I enable ufw, and disable ssh. Is my base install Ubuntu 12.04 safe from the outside world?

I installed Ubuntu 12.04 I then installed Gufw, enabled it and Set every known application setting to "Deny". I never installed sshdaemon so I think its off. My machine still responds to pings... ...
1
vote
1answer
1k views

Windows VirtualBox can't browse network

I'm running Windows XP as a VirtualBox guest OS under Ubuntu 11.10, and I can't browse the Windows network. It seems like I can connect to some specific network shares, maybe only ones that are ...
4
votes
2answers
16k views

How do I allow all possible IPs for Gmail servers through my ufw firewall?

I am currently using the following rule: ufw allow out from my_local_ip to any port 587 This is a little too lax for my liking. I would like to tighten it up and restrict it to only gmail's smtp ...
7
votes
2answers
5k views

What do UFW's audit log entries mean?

I'm sometimes getting a lot of these AUDIT log entries in ... [UFW AUDIT] IN= OUT=eth0 SRC=176.58.105.134 DST=194.238.48.2 LEN=76 TOS=0x10 PREC=0x00 TTL=64 ID=32137 DF PROTO=UDP SPT=36231 DPT=123 ...
1
vote
1answer
106 views

How to add a rule for loggin packets in ufw

I'm seeing a lot of connections with source 0.0.0.0 and destination 0.0.0.0 in conntrack. I want to log these packets which have source 0.0.0.0 and destination 0.0.0.0 so that I can digg this issue ...
7
votes
1answer
2k views

How to set an NFS network?

I want to merge information found here and there in order to record in one answer all steps to set my NFS network between my two Ubuntu PCs This is useful time to time, for example when switching to ...
1
vote
0answers
2k views

UFW Settings - Application Integration [closed]

I have installed the Ubuntu system, and deny both incoming and outgoing ports loosing internet access. Now I want access only for my Firefox that I have installed separately from the Firefox website ...
11
votes
1answer
22k views

What are ICMP redirects and should they be blocked?

After enabling ufw and the Tiger security auditor, I see warnings saying: The system accepts ICMP redirection messages What are ICMP redirection messages? Should they be disabled for security ...
3
votes
0answers
959 views

Why is UFW blocking outgoing connections?

UFW is blocking some outgoing connections on my server, such as Akismet, the spam killing plugin for my Wordpress site. According to Akismet's firewall info I need to allow contact with four IPs. My ...
2
votes
0answers
584 views

UFW give errors and won't auto start at boot [closed]

I just tried to enable ufw on my server, it gave me this error : ERROR: problem running ufw-init When I tried the second time, it worked. When I tried to set the default rule "sudo ufw default ...
4
votes
1answer
7k views

nfs is blocked by ufw even though ports are opened

I've set up an nfsv4 server and it's working fine, however the firewall is blocking nfs even if port 2049 and 111 are open. I know nfs uses some random ports that change at every boot, but how can i ...
2
votes
1answer
545 views

Looking for IPTABLES and UFW readily available, the best proven rules

ok i am up with UBUNTU finally, and liked the distro! particularly ufw, synaptic and software manager. as i am pretty blind newbie to linux, i need some help securing Ubuntu desktop. I've gone ...
3
votes
3answers
2k views

Why is Ubuntu permissive with outgoing connections by default?

I am pretty newbie to Linux, as most of computers for resources in my school use Linux, I just installed Ubuntu to learn. By default iptables and ufw sets policy as under: IPTABLES -P INPUT DROP ...
7
votes
4answers
16k views

What rules to use for UFW?

I've decided to enable the UFW that comes with Ubuntu just to make my system even more secure (especially after watching a video of a person whose computer actually got infected!), and I've enabled ...
2
votes
1answer
279 views

Enforce outgoing port for a machine inside LAN

I'm running Ubuntu Server (natty) in as a gateway/firewall in front of a private network. I have successfully enabled IP forwarding and NAT so the machines behind the firewall can connect to Internet ...
9
votes
1answer
855 views

Precautionary security measures for a home user? (firewall, antivirus, etc)

I just recently made the switch from Windows to Ubuntu, and I'm just a little paranoid when it comes to security measures. I've looked around and from what I've read, security is not as big a concern ...
5
votes
1answer
223 views

How do I accept inbound connections for a specific program?

Windows firewall allows to specify a program that will accept inbound connections no matter on which port(s) is listening (instead of specifying the port(s) to allow for that program). Is this ...
1
vote
4answers
6k views

Set UFW before.rules without restart of server

I use UFW on my Ubuntu server. Unfortunately there are no rules in UFW to port forward to another machine. What you need to do is edit /etc/before.rules and put routing commands there, for example # ...
4
votes
1answer
2k views

setting up ufw for a website, I want to to disallow everything except ssh, e-mail, and http

I have read the basic instructions here: https://help.ubuntu.com/community/UFW I want to sudo ufw default deny and then sudo ufw allow ssh sudo ufw allow smtp sudo ufw allow www sudo ufw allow ...
9
votes
2answers
4k views

potential ufw and fail2ban conflicts

Will running both fail2ban and ufw cause problems? I noticed that fail2ban modifies iptables rules, but ufw already has a ton of iptables rules defined... so I'm not sure if fail2ban will mess these ...
4
votes
1answer
2k views

How to connect to a CISCO VPN through UFW

I am running Ubuntu 11.04 (64 bits version) and would like to be able to get connected to the VPN server (CISCO) of my company. I am able to get connected to the VPN server when I disable UFW but, ...
6
votes
6answers
6k views

UFW firewall still blocking SMB despite adding rules

I have an Ubuntu PC with ufw firewall (GUI version). I have added the preset Samba service, in and out, and even tried adding the ports manually (135-139, 445, UDP and TCP, in and out), but it still ...
12
votes
5answers
8k views

See configured rules even when inactive

I'm wondering if it's possible to get UFW to list the configured firewall rules even when it's not enabled. I only have ssh access to the server at this time, and I don't want to enable UFW if there's ...