UDP 1812
Synopsis
- UDP port 1812 is the IANA-assigned port for RADIUS authentication traffic.
- RADIUS servers such as FreeRADIUS, Microsoft Network Policy Server (NPS), Cisco Identity Services Engine (ISE), Aruba ClearPass, and Radiator listen on UDP/1812 for authentication.
- Network devices and Wi‑Fi controllers (Cisco IOS/ASA/AnyConnect, Juniper EX/SRX, Aruba/HPE switches and controllers, Ubiquiti UniFi, MikroTik, Palo Alto Networks) send 802.1X, VPN, and admin-login requests to RADIUS on UDP 1812.
- VPN/remote access products like Fortinet FortiGate, pfSense, OpenVPN Access Server, and SonicWall use RADIUS on UDP 1812 for user authentication.
- Captive portal and NAC solutions, including eduroam infrastructure and PacketFence, use UDP 1812 to authenticate users.
- Cloud/identity integrations such as Duo Authentication Proxy, Okta RADIUS Agent, JumpCloud RADIUS, and cloud RADIUS providers (SecureW2, Foxpass) operate on or connect via UDP 1812.
- Microsoft’s Azure MFA NPS Extension works with NPS over UDP 1812 to add MFA to RADIUS auth.
- WPA2/WPA3‑Enterprise (802.1X) deployments rely on APs/controllers forwarding EAP to RADIUS servers over UDP 1812.
- Security note: Exposed RADIUS/UDP 1812 services are commonly targeted for credential brute‑force and have been abused for UDP reflection/amplification DDoS when misconfigured.
Observed activity
Last 30 days
Detailed chart