ufw

ファイアウォールです。

$ ufw --help

Usage: ufw COMMAND

Commands:
  enable			enables the firewall
  disable			disables the firewall
  default ARG			set default policy to ALLOW or DENY
  logging ARG			set logging to ON or OFF
  allow|deny RULE		allow or deny RULE
  delete allow|deny RULE	delete the allow/deny RULE
  status			show firewall status
  version			display version information

Application profile commands:
  app list			list application profiles
  app info PROFILE		show information on PROFILE
  app update PROFILE		update PROFILE
  app default ARG		set profile policy to ALLOW, DENY or SKIP