關於「NTP port」標籤，搜尋引擎有相關的訊息討論：

Public NTP - Google for Developersdevelopers.google.com › timeWhy does NTP require bi-directional firewall access to UDP port 123?superuser.com › questions › why-does-ntp-require-bi-direc...NTPD: use an unrestricted port for communication - Stack Overflowstackoverflow.com › que