Bindaddress

Bindaddress refers to the local network address a server or service binds to when opening a listening socket. It designates which network interface on the host will accept incoming connections, and it is typically specified together with a port. The term appears in various software configurations under forms such as bind-address, bindaddress, or listen_addresses, reflecting the same underlying concept: the bound local address that the service uses to listen for traffic.

In practice, binding to a specific address controls accessibility. Binding to a loopback address (for example, 127.0.0.1 or ::1) restricts access to the local machine, while binding to all interfaces (0.0.0.0 for IPv4 or :: for IPv6) makes the service reachable from any network interface on the host. On dual‑stack systems, care is needed to manage IPv4 and IPv6 bindings, as some software binds separately for each protocol.

Common examples in software configurations include MySQL (bind-address in my.cnf), Redis (bind directive), PostgreSQL (listen_addresses), and web servers like Apache and Nginx (Listen or bind directives). In each case, the setting determines which network interfaces the service will listen on. Some systems also allow multiple addresses or hostnames to be used, which the software resolves to one or more local addresses.

Security and maintenance considerations are important when choosing a bindaddress. Restricting binding to internal interfaces or trusted subnets reduces exposure to unwanted traffic, while binding to all interfaces should be avoided for services that do not require public access. Verifying the active bound address with tools such as netstat or ss helps diagnose connectivity issues.