Port 161: SNMP
Port 161 is SNMP, used to poll switches, routers, and servers for health and traffic stats. Devices send unsolicited alerts (traps) from port 162.
UDPManagementUnencrypted by defaultIANA assigned
| Port number | 161 |
|---|---|
| Service | Simple Network Management Protocol |
| Protocol | UDP |
| Category | Management |
| Default encryption | No |
Security note. Port 161 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 161 used for?
Port 161 is SNMP, used to poll switches, routers, and servers for health and traffic stats. Devices send unsolicited alerts (traps) from port 162.
Is port 161 TCP or UDP?
Port 161 (SNMP) uses UDP.
Is port 161 secure?
Port 161 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.
Should I open port 161 on my firewall?
Only if you specifically need SNMP. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.