INFO: Host Name May Map to Multiple IP Addresses

ID: Q110703

The information in this article applies to:

Microsoft Win32 Software Development Kit (SDK), versions 3.1, 3.5, 3.51, 4.0

SUMMARY

The sockets function gethostname() returns a string that identifies the name of the local host. Each host has only one "official" name, regardless of how many IP addresses it has, but there may be several "aliases" for the host.

In TCP/IP, there is not a one-to-one mapping between host name and IP address. The mapping is one-to-many: one host name can have multiple IP addresses.

The sockets function getsockname() returns the sockaddr that the socket is bound to.

Additional query words:

Keywords          : kbnetwork kbAPI kbNTOS310 kbNTOS350 kbNTOS351 kbNTOS400 kbSDKPlatform kbWinsock kbGrpNet 
Issue type        : kbinfo

Last Reviewed: July 31, 1998