Hi there,
By default, NPS sends and receives RADIUS traffic by using User Datagram Protocol (UDP) ports 1812, 1813, 1645, and 1646.
The RADIUS protocol uses UDP packets. There are two UDP ports used as the destination port for RADIUS authentication packets (ports 1645 and 1812). Note that port 1812 is in more common use than port 1645 for authentication packets.
AD uses the following ports to support user and computer authentication, according to the Active Directory and Active Directory Domain Services Port Requirements article: SMB over IP (Microsoft-DS): port 445 TCP, UDP. Kerberos: port 88 TCP, UDP. LDAP: port 389 UDP.
--------------------------------------------------------------------------------------------------------------------------------
--If the reply is helpful, please Upvote and Accept it as an answer--