nmbd

nmbd is the NetBIOS name service daemon in the Samba software suite. It provides NetBIOS name resolution and LAN browsing services for SMB/CIFS networks, primarily on Unix-like systems running Samba. nmbd handles NetBIOS name queries from clients and can act as a WINS (Windows Internet Name Service) server to centralize name resolution within a local network. It also participates in the Browser Service Protocol to maintain a listing of available computers and to support Master Browser elections in a Windows workgroup environment.

Operation and configuration: nmbd runs as a background service and works in conjunction with smbd to enable Windows-style networking on Unix systems. It reads configuration directives from smb.conf, including workgroup, netbios name, and whether to enable WINS support. It listens to NetBIOS-related traffic on UDP ports 137 (name service) and 138 (datagram service) and communicates with other NetBIOS name servers and clients across the LAN. When configured as a WINS server, nmbd responds to name queries and can assist in name resolution for other hosts.

Modern usage: In many networks, DNS and Active Directory have reduced the centrality of NetBIOS and nmbd. As a result, some deployments disable nmbd or rely on DNS-based discovery. Nevertheless, nmbd remains a compatibility option for legacy Windows networks and mixed environments that require NetBIOS name resolution, LMHOSTS support, or browser functionality.

See also: Samba, SMB/CIFS, NetBIOS, WINS, LMHOSTS, Browser service protocol.