Port 1813: RADIUS accounting
Port 1813 is RADIUS accounting, which logs session start, stop, and usage data after RADIUS authentication on port 1812 succeeds. ISPs and enterprise networks use it to track connection time and data usage.
UDPAuthenticationUnencrypted by defaultIANA assigned
| Port number | 1813 |
|---|---|
| Service | RADIUS accounting |
| Protocol | UDP |
| Category | Authentication |
| Default encryption | No |
Security note. Port 1813 is not encrypted by default. Restrict it to trusted networks, or use an encrypted alternative where one exists, to avoid exposing credentials and data in transit.
Frequently asked questions
What is port 1813 used for?
Port 1813 is RADIUS accounting, which logs session start, stop, and usage data after RADIUS authentication on port 1812 succeeds. ISPs and enterprise networks use it to track connection time and data usage.
Is port 1813 TCP or UDP?
Port 1813 (RADIUS accounting) uses UDP.
Is port 1813 secure?
Port 1813 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.
Should I open port 1813 on my firewall?
Only if you specifically need RADIUS accounting. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.