ipnodes - The IP node name database
The ipnodes file contains information regarding the known IP nodes (both
IPv4 and IPv6) on the network. For each node a single line should be
present with the following information:
IP_address canonical_nodename aliases
Items are separated by any number of blanks or tab characters, or both.
The # (number sign) indicates the beginning of a comment; characters up to
the end of the line are not interpreted by routines which search the file.
Network addresses, both IPv4 and IPv6, are specified in the IPv6 notation
using the inet_pton() routine from the Internet address manipulation
library. Node names may contain any printable character other than a field
delimiter, newline, or comment character.
Functions: getaddrinfo(3), getnameinfo(3), inet_pton(3).