What Is the Data Size of the Sockaddr Structure?


Angela Bailey

The sockaddr structure is a fundamental component of network programming in C and C++. It is used to define and manipulate network addresses. Understanding its data size is important for efficient memory management and network communication.

What is the sockaddr structure?

The sockaddr structure is a generic socket address structure that can be cast to more specific address structures. It is defined in the sys/socket.h header file and has the following definition:

struct sockaddr {
    unsigned short sa_family; // address family, AF_xxx
    char sa_data[14]; // 14 bytes of protocol-specific address

The sa_family member specifies the address family used by the socket, such as AF_INET (IPv4) or AF_INET6 (IPv6). The sa_data member contains the protocol-specific address, which can be an IP address or a path name for Unix domain sockets.

Data size of the sockaddr structure

The total data size of the sockaddr structure is 16 bytes. This includes 2 bytes for the sa_family member and 14 bytes for the sa_data member. Regardless of the specific address family or protocol, the size of this structure remains constant.


  • The size of each member within the sockaddr structure may vary depending on the platform and compiler.
  • In modern systems, it is common to use more specific address structures like struct sockaddr_in (for IPv4) or struct sockaddr_in6 (for IPv6).
  • The sockaddr structure provides a way to handle different address families using a single interface.


The sockaddr structure is a crucial component in network programming, allowing developers to work with different address families. Understanding its data size helps in efficient memory management and network communication. By utilizing specific address structures, developers can handle IPv4 and IPv6 addresses with ease.

Now that you know the data size of the sockaddr structure, you can confidently handle socket programming tasks with better memory management and improved networking capabilities.

Discord Server - Web Server - Private Server - DNS Server - Object-Oriented Programming - Scripting - Data Types - Data Structures

Privacy Policy