nsswitch.compat and nsswitch.conf (points!)

[Christian Deutsch_1]

Hi folks,

I read in the following post (http://forums13.itrc.hp.com/service/forums/questionanswer.do?admit=109447627+1286194069555+28353475&threadId=1233205), that name resolution "default behaviour" if there is no nsswitch.conf file can be seen in /etc/nsswitch.hp_defaults (and /etc/nsswitch.compat?).

So in fact, even if no nsswitch.conf file is present, name resolution via /etc/hosts will still work, e.g. using /usr/bin/nslookup on HP-UX 11.31. However, programs using gethostbyname() may be able to "accept" a certain IP address but *not* be able to resolve the hostname, even though it is present in /etc/hosts.

So what should I expect? Is it correct to assume that every HP-UX administrator will have an nsswitch.conf file anyway to ensure that programs relying on gethostbyname() will not fail?

Informed, helpful replies will be generously rewarded with points!

Thanks, Christian

[Laurent Menase]

Hi,

Default behaviour is to try dns then /etc/hosts after a timeout

if you have no reslov.conf, the dns will be try on 127.0.0.1
.
So my advise:
Define exactly what you want to happen on gethostbyname in /etc/nsswitch.conf
and if you want the use of dns, then define a /etc/resolv.conf

if you don't want dns resolution it is very important to define a nsswitch.conf

[rick jones]

Keep in mind that nslookup is not known for its slavish adherence to an nsswitch file.

FWIW, gethostbyname()/gethostbyaddr() is very "old school" these days - applications should be written to use getaddrinfo()/getnodeinfo().