NetNews Usenet Archive 1992 #19/NN_1992_19.iso/spool/comp/sys/sun/admin/5834

Text File | 1992-08-25 | 1.7 KB | 34 lines

Newsgroups: comp.sys.sun.admin
Path: sparky!uunet!europa.asd.contel.com!gatech!destroyer!fmsrl7!lynx!zia.aoc.nrao.edu!rmilner
From: [e-mail] (Ruth Milner)
Subject: Re: how to determine if ypservices available
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Ruth Milner)
Organization: National Radio Astronomy Observatory, Socorro NM
References: <[e-mail]>
Date: Tue, 25 Aug 92 18:31:45 GMT
Lines: 22

In article <[e-mail]> [e-mail] (Chuck Strickland) writes:
> Periodically we are required to set up a system as standalone to go off
> the net for various reasons.
> [...] comes back on the net, sometimes after a couple of months, the yp maps
> a extremely out of date. Thus we have many strange problems until we realize
> this system is on
> the net and other hosts have bound to it. Thus using outdated maps.
>
> A program that calls ypbind, if after
> a few seconds no server responds, assume you are off the net and exec
> ypserv. If a server responds, assume you are on the net and dont exec to
> ypserv and just remain a client.

If your YP master stays at the same IP address most of the time, why not use
"ping" instead? Before starting up YP, ping the address of the master (and
maybe one or two slaves as well, in case the master is down). If it answers,
you're on the net and you only want ypbind (assuming there's another server
on the same subnet, but if not you can use ypset to force the binding). If
nothing answers, you aren't, and you start ypserv yourself.
--
Ruth Milner                          NRAO/VLA                  Socorro NM
Computing Division Head      [e-mail]