شرح تفعيل الجدار الناري ubuntu 13.10

من خلال terminal 

• First, ufw needs to be enabled. From a terminal prompt enter:

  sudo ufw enable
  

• To open a port (ssh in this example):

  sudo ufw allow 22
  

• Rules can also be added using a numbered format:

  sudo ufw insert 1 allow 80
  

• Similarly, to close an opened port:

  sudo ufw deny 22
  

• To remove a rule, use delete followed by the rule:

  sudo ufw delete deny 22
  

• It is also possible to allow access from specific hosts or networks to a port. The following example allows ssh access from host 192.168.0.2 to any ip address on this host:

  sudo ufw allow proto tcp from 192.168.0.2 to any port 22
  

  Replace 192.168.0.2 with 192.168.0.0/24 to allow ssh access from the entire subnet.
• Adding the --dry-run option to a ufw command will output the resulting rules, but not apply them. For example, the following is what would be applied if opening the HTTP port:

   sudo ufw --dry-run allow http
  

  *filter
  :ufw-user-input - [0:0]
  :ufw-user-output - [0:0]
  :ufw-user-forward - [0:0]
  :ufw-user-limit - [0:0]
  :ufw-user-limit-accept - [0:0]
  ### RULES ###
  
  ### tuple ### allow tcp 80 0.0.0.0/0 any 0.0.0.0/0
  -A ufw-user-input -p tcp --dport 80 -j ACCEPT
  
  ### END RULES ###
  -A ufw-user-input -j RETURN
  -A ufw-user-output -j RETURN
  -A ufw-user-forward -j RETURN
  -A ufw-user-limit -m limit --limit 3/minute -j LOG --log-prefix "[UFW LIMIT]: "
  -A ufw-user-limit -j REJECT
  -A ufw-user-limit-accept -j ACCEPT
  COMMIT
  Rules updated
  

• ufw can be disabled by:

  sudo ufw disable
  

• To see the firewall status, enter:

  sudo ufw status
  

• And for more verbose status information use:

  sudo ufw status verbose
  

• To view the numbered format:

  sudo ufw status numbered