Port 111: RPCbind
Port 111 is rpcbind, formerly called portmapper, which tells clients which port an ONC RPC service such as NFS is actually listening on. It has no authentication of its own, so it should never face the open internet.
TCP/UDPCore servicesUnencrypted by defaultIANA assigned
| Port number | 111 |
|---|---|
| Service | ONC RPC / rpcbind (portmapper) |
| Protocol | TCP/UDP |
| Category | Core services |
| Default encryption | No |
Security note. Port 111 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 111 used for?
Port 111 is rpcbind, formerly called portmapper, which tells clients which port an ONC RPC service such as NFS is actually listening on. It has no authentication of its own, so it should never face the open internet.
Is port 111 TCP or UDP?
Port 111 (RPCbind) uses TCP/UDP.
Is port 111 secure?
Port 111 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.
Should I open port 111 on my firewall?
Only if you specifically need RPCbind. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.