Which port number is used by RADIUS for authentication?

Which port number is used by RADIUS for authentication?

• A. 8080
• B. 1812
• C. 1723
• D. 1813

Answer: (B)

RADIUS operates over UDP, and the default destination port for authentication requests is 1812 on the RADIUS server. This separation allows authentication to travel on one port while accounting uses another, commonly 1813. The other ports serve different services: 8080 is typically web traffic, 1723 is used for PPTP VPN, and 1813 is used for accounting, not authentication. While older deployments sometimes used 1645/1646, the modern standard for authentication is 1812 with accounting on 1813.

RADIUS operates over UDP, and the default destination port for authentication requests is 1812 on the RADIUS server. This separation allows authentication to travel on one port while accounting uses another, commonly 1813. The other ports serve different services: 8080 is typically web traffic, 1723 is used for PPTP VPN, and 1813 is used for accounting, not authentication. While older deployments sometimes used 1645/1646, the modern standard for authentication is 1812 with accounting on 1813.