HP-UX IPv6 Transport Administrator's Guide for TOUR 2.0 (April 2004, rev 2)

IPv6 Software and Interface Technology
Name and Address Lookup for IPv6
Chapter 7 71
Thus, if DNS has not been set up as the definitive source, and files
(/etc/hosts) may need to be used for address and host name resolution,
HP recommends adding the following entry to /etc/nsswitch.conf:
ipnodes: dns [NOTFOUND=continue] files
Or if /etc/hosts is to be the primary Name Service
ipnodes: files [NOTFOUND=continue] dns
NOTE You can not specify NIS or NIS+ on the ipnodes entry.
Migrating Name and IPv6 Address Lookup
Most sites test IPv6 on a development subnetwork before deploying it on
a larger scale. These sites typically add IPv6 address and host names to
the /etc/hosts files on IPv6 hosts, then change their hosts lookup policy
to search files.
HP recommends that you maintain at least a minimal /etc/hosts file
that includes important addresses like gateways, root servers, and your
host’s own IP address. HP also recommends that you include the word
files in the hosts and ipnodes lines of /etc/nsswitch.conf to help
ensure a successful system boot using the /etc/hosts file when DNS is
not available.