2049 NFS TCP/UDP

What it's for

Port 2049 is the port NFS (Network File System) uses to share directories between Unix-like systems over a network, letting a remote filesystem appear and behave as though it were mounted locally. It's a long-standing staple of Unix/Linux network storage, commonly used for shared home directories, centralized application data, and network-attached storage appliances.

Protocol basics

Modern NFS (version 4 and later) consolidated onto a single port, 2049, running over both TCP and UDP, whereas older NFS versions relied on a separate port-mapping service (rpcbind) to negotiate additional dynamic ports for various NFS-related services — a design that made older NFS notoriously firewall-unfriendly. NFSv4 also folded in file locking and other previously separate services, simplifying deployment considerably. Since NFS traffic can carry unencrypted file data and traditionally relies on network-level trust rather than strong per-user authentication, it's generally kept on trusted internal networks rather than exposed across untrusted boundaries.