NTP, SNTP and PTP: what time synchronization do I need? | INCIBE-CERT
InfoSec Handlers Diary Blog - SANS Internet Storm Center
Network Time Protocol - Wikipedia
InfoSec Handlers Diary Blog - SANS Internet Storm Center
LayerStack Tutorials - LayerStack - How to check if TCP / UDP port is open on Linux & Windows Cloud Servers
How Does Network Time Protocol Work | Zindagi Technologies
Network Time Security: new NTP authentication mechanism | APNIC Blog
Setting up a Local / Internal NTP Server to allow time synchronization - Communities
Secure Tunnelled NTP Proof of Concept | Lightship Security
NTP Port Number and Configuration Tutorial For Linux Local System – POFTUT
TCP and UDP ports | CCNA#
Ports, protocols and connections - Janitza electronics
Networking Requirements for SDP - MetaAccess Cloud and SDP
NTP best practices - KB & Manual - ADAMnetworks
The Simple Network Time Protocol (SNTP) port
Why does NTP require bi-directional firewall access to UDP port 123? (2 Solutions!!) - YouTube
Network Time Protocol (NTP) (Building Internet Firewalls, 2nd Edition)
Windows Firewall
Network Time Security: new NTP authentication mechanism | APNIC Blog
InfoSec Handlers Diary Blog - SANS Internet Storm Center
Still blocking ntp ports for outbound 123? | AT&T Community Forums
Fast Troubleshooting for Windows Time Service (w32time) Synchronization
NTP Server and Client Configuration - Systems & Network Administrator
Time Synchronization with NTP
Fast Troubleshooting for Windows Time Service (w32time) Synchronization
