TCP/IPv6 Configuration and Management Manual (G06.24+)

NonStop TCP/IPv6 Protocols and Configuration Files
HP NonStop TCP/IPv6 Configuration and Management Manual—524523-008
D-9
HOSTS File
Consider the example that follows:
Notice that the first entry beginning with 127.0.0.1 has several aliases. This means that
the user can use any of these aliases to communicate with the destination host that
has the IP address 127.0.0.1.
The alias for a host is optional, and a host can have more than one alias; however, the
aliases must be separated by spaces and be on the same line. The other entries
(beginning with 128.1.1.1) each have two host names: one in uppercase and one in
lowercase. Neither the host name nor the alias is case sensitive.
You can add comments to the HOSTS file by preceding the comment with a pound
sign (#). You can add comments as separate lines of the file or after the IP address
and host entry. Include comments like the line name or hardware address that can be
used for reference.
As indicated earlier, you must configure the DNR to use a HOSTS file; otherwise DNS
is assumed. Use the ADD DEFINE command of TACL to set the TCPIP^HOST^FILE
environment variable.
The TACL ADD DEFINE command that follows is an example:
2> ADD DEFINE =TCPIP^HOST^FILE, FILE $SYSTEM.ZTCPIP.HOSTS
Remember, you must issue such an ADD DEFINE command to indicate that a HOSTS
file is to be used, as well as the name of the desired HOSTS file. Otherwise, the DNR
assumes it must use DNS and consults the RESCONF file.
Note that you also must set the TCPIP^HOST^FILE parameter at each terminal that
uses the TCP/IP network. Then, when you invoke a TCP/IP application with reference
to a host name, the DNR uses the appropriate HOSTS file. For convenience, include
such an ADD DEFINE command as an entry in the TACLCSTM file, so that the
command is executed automatically every time you log onto the NonStop system.
# HOSTS file
127.0.0.1 me loop geoff mark cyclone
# \CB2 is the gateway between subnets for \ENC1 and \CB1
128.1.1.1 CB21 cb21 # on subnet 1.0, lan01 08008E0002A6
128.1.2.1 CB22 cb22 # on subnet 2.0, lan02 08008E000B2D
#
Note. The IP address 127.0.0.1 is a TCP/IP convention that refers to “this” host or loopback.
Note. For information about the order in which the sockets library searches the HOSTS and
IPNODES files, see Using the Domain Name Server (DNS) and IPNODES and HOSTS Files
on page 6-6.