NAME

hosts − host name data base

DESCRIPTION

The hosts file contains information on the known hosts on the DARPA Internet.  This file contains:

• lines of text with one or more fields separated by exactly one space

• optional comments that begin with a pound sign (#) and continue to the end of the line

The first field contains the 4 byte Internet address.  This address is a logical address which identifies a host on the network.  You must specify all four bytes of the address even if any byte is 0.  Each byte may be specified in decimal or hexadecimal notation separated by a period.  (Precede hexadecimal digits by 0x.)  For example, 89.0.0.1.  (See inet(7) for a complete explanation of the “.” notation.)

The second field contains the official host name corresponding to the Internet address.  This name is an arbitrary string, preferably long enough to keep hosts unique on the network.  Typically, a name class is chosen, such as alabama, alaska, arkansas ... or washington, adams, jefferson ... 

The subsequent fields contain aliases or nicknames for a particular host.  These aliases are other names for a particular system.  Typically this is a shorter name (al, ak, ar ... or george, john, tom), and may not be unique across the network.  For example, the host alaska could have the following address and alias:

129.0.9.5 alaska ak

FILES

/etc/hosts

SEE ALSO

hosts.equiv(4)

Version 2.4  —  September 29, 2021