TLDR
Enter a command. For example: systemctl, apt key, genkernel.

ufw

 
Uncomplicated Firewall. Frontend for iptables aiming to make configuration of a firewall easier. More information: https://wiki.ubuntu.com/UncomplicatedFirewall.
 
  • Enable ufw:
     
    ufw enable
     
  • Disable ufw:
     
    ufw disable
     
  • Show ufw rules, along with their numbers:
     
    ufw status numbered
     
  • Allow incoming traffic on port 5432 on this host with a comment identifying the service:
     
    ufw allow {{5432}} comment "{{Service}}"
     
  • Allow only TCP traffic from 192.168.0.4 to any address on this host, on port 22:
     
    ufw allow proto {{tcp}} from {{192.168.0.4}} to {{any}} port {{22}}
     
  • Deny traffic on port 80 on this host:
     
    ufw deny {{80}}
     
  • Deny all UDP traffic to ports in range 8412:8500:
     
    ufw deny proto {{udp}} from {{any}} to {{any}} port {{8412:8500}}
     
  • Delete a particular rule. The rule number can be retrieved from the ufw status numbered command:
     
    ufw delete {{rule_number}}

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