From the project home page:
- Ufw stands for Uncomplicated Firewall, and is a program for managing a netfilter firewall. It provides a command line interface and aims to be uncomplicated and easy to use.
A very simplistic configuration which will deny all by default, allow any protocol from inside a 192.168.0.1-192.168.0.255 LAN, and allow incoming Deluge and SSH traffic from anywhere:
# ufw default deny # ufw allow from 192.168.0.0/24 # ufw allow Deluge # ufw allow SSH
The next line is only needed once the first time you install the package:
# ufw enable
Follow that by enabling
Finally, query the rules being applied via the status command:
# ufw status
Status: active To Action From -- ------ ---- Anywhere ALLOW 192.168.0.0/24 Deluge ALLOW Anywhere SSH ALLOW Anywhere
The status report shows the rules added by the user. For most cases this will be what is needed, but it is good to be aware that builtin-rules do exist. These include filters to allow UPNP, AVAHI and DHCP replies. In order to see all rules setup
# ufw show raw
may be used, as well as further reports listed in the manpage. Since these reports also summarize traffic, they may be somewhat difficult to read. Another way to check for accepted traffic:
# iptables -S | grep ACCEPT
While this works just fine for reporting, keep in mind not to enable the
iptables service as long as you use
ufw for managing it.
Adding other applications
The PKG comes with some defaults based on the default ports of many common daemons and programs. Inspect the options by looking in the
/etc/ufw/applications.d directory or by listing them in the program itself:
# ufw app list
If users are running any of the applications on a non-standard port, it is recommended to simply make
/etc/ufw/applications.d/custom containing the needed data using the defaults as a guide.
Example, deluge with custom tcp ports that range from 20202-20205:
[Deluge-my] title=Deluge description=Deluge BitTorrent client ports=20202:20205/tcp
Should you require to define both tcp and udp ports for the same application, simply separate them with a pipe as shown: this app opens tcp ports 10000-10002 and udp port 10003:
One can also use a comma to define ports if a range is not desired. This example opens tcp ports 10000-10002 (inclusive) and udp ports 10003 and 10009
Drawing on the Deluge/Deluge-my example above, the following will remove the standard Deluge rules and replace them with the Deluge-my rules from the above example:
# ufw delete allow Deluge # ufw allow Deluge-my
Query the result via the status command:
# ufw status
Status: active To Action From -- ------ ---- Anywhere ALLOW 192.168.0.0/24 SSH ALLOW Anywhere Deluge-my ALLOW Anywhere
Rate limiting with ufw
ufw has the ability to deny connections from an IP address that has attempted to initiate 6 or more connections in the last 30 seconds. Users should consider using this option for services such as sshd.
Using the above basic configuration, to enable rate limiting we would simply replace the allow parameter with the limit parameter. The new rule will then replace the previous.
# ufw limit SSH
# ufw status
Status: active To Action From -- ------ ---- Anywhere ALLOW 192.168.0.0/24 SSH LIMIT Anywhere Deluge-my ALLOW Anywhere
AUR is an easy to use Ubuntu/Linux firewall, powered by ufw.
Gufw is an easy, intuitive, way to manage your Linux firewall. It supports common tasks such as allowing or blocking pre-configured, common p2p, or individual ports port(s), and many others! Gufw is powered by ufw, runs on Ubuntu, and anywhere else Python, GTK, and Ufw are available.
AUR is KDE4 control module for ufw. The following features are supported:
- Enable/disable firewall
- Configure firewall default settings
- Add, edit, and remove rules
- Re-order rules via drag\'n\'drop
- Import/export of rules
- Setting of some IP tables modules
The module will appear under "Network and Connectivity" category.