HP-UX HB v13.00 Ch-10 - Network Services

HP-UX Handbook – Rev 13.00 Page 7 (of 26)
Chapter 10 Network Services
October 29, 2013
subdomains should be found, a search statement can be used (instead of the domain statement),
e.g.:
search grc.hp.com, bbn.hp.com
Up to three nameserver statements can be entered into this file. These must be specified by IP
address, not hostname.
Current versions of libc allow a custom timeout for fallback through directives (retry and
retrans), see man 4 resolver page for details.
The options retrans and retry are a good choice where nameservers are not always reliable.
retrans <value in milliseconds>
retry <number of retries>
Verifying hostname resolution
Historically, nslookup has been the tool of choice for resolving host names; however, this tool is
not a single standard (vendor implementation details vary) and suffers from other drawbacks.
One major drawback is that nslookup does not use the same library as resolver calls and uses a
different algorithm for probing nameservers. The nslookup tool will often falsely report a very
long response time for looking up a host address which can be quickly resolved by using a
service (such as telnet or ping) which uses the function calls previously described. As previously
stated various versions are available from different vendors. HP’s version was enhanced to be
NSS aware.
The nslookup tool is not, going forward, the best tool to use for DNS queries. A better
alternative is HP’s proprietary tool nsquery which is also NSS aware.
For instance,
$ nsquery hosts `hostname`
Using "files dns" for the hosts policy.
Searching /etc/hosts for rx7620b
Hostname: rx7620b.example.com
Address: 10.226.90.20
Switch configuration: Terminates Search