ubuntu server install 후 설정ubuntu ufw(uncomplicated firewall) 설정우분투 서버 - 방화벽 UFW 설정UFW - 우분투 방화벽FireWall Ubuntu DesktopUFW Allowing IP range - ufw allow proto tcp from xxx.xxx.0.0/xxx.xxx.255.255 to any port 22 - The /24 at the end of the address is the network mask, in CIDR notation. You can look up netmask calculators to figure out what it means, but basically /24 means a netmask of 255.255.255..