# WHATPORT(2049)

## NAME

port 2049 — NFS — The Network File System — whole file systems mounted over the network, on the best-known port in the 2000s.

Protocol: TCP/UDP  
IANA registry

## DESCRIPTION

The NFS server daemon (nfsd) answers here, serving remote file system operations over TCP or UDP; RFC 5665 also registers NFS over SCTP. NFSv2 and v3 (RFC 1813) needed rpcbind on 111 plus separately bound mountd, statd and lockd helpers, while NFSv4 (RFC 8881) dropped that entirely and specifies 2049 as the single well-known port carrying mounting and locking in-band. You will find it on Linux and BSD file servers, NAS appliances, ESXi datastores and macOS, usually alongside 111 if v3 is still enabled. With the default AUTH_SYS flavour the server trusts the client's claimed UID and GID, so the export's access control is really the client's honesty plus your export list.

## EXPOSURE

**Do not expose.** AUTH_SYS lets anyone who can reach the port assert any UID, so an internet-facing export is readable and often writable by strangers. Keep NFS on a private network or a VPN, and require Kerberos (sec=krb5p) if it must cross untrusted paths.

## CHECK

```sh
showmount -e TARGET
```

## SEE ALSO

- spec — [RFC 8881 — Network File System (NFS) Version 4 Minor Version 1 Protocol](https://www.rfc-editor.org/rfc/rfc8881.html) (rfc-editor.org)
- spec — [RFC 1813 — NFS Version 3 Protocol Specification](https://www.rfc-editor.org/rfc/rfc1813.html) (rfc-editor.org)
- spec — [RFC 5665 — IANA Considerations for Remote Procedure Call (RPC) Net Identifiers](https://www.rfc-editor.org/rfc/rfc5665.html) (rfc-editor.org)
- iana — [IANA Service Name and Transport Protocol Port Number Registry](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml) (iana.org)

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HTML: <https://whatport.net/2049/> · JSON: <https://whatport.net/2049.json> · full dataset: <https://whatport.net/ports.json>