Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!elroy.jpl.nasa.gov!decwrl!sgi!vjs@rhyolite.wpd.sgi.com
From: vjs@rhyolite.wpd.sgi.com (Vernon Schryver)
Newsgroups: comp.sys.sgi
Subject: Re: yp problem
Summary: ypbind uses UDP broadcasts to discover ypserv's
Message-ID: <103360@sgi.sgi.com>
Date: 13 May 91 04:42:24 GMT
References: <9105120711.AA01176@>
Sender: guest@sgi.sgi.com
Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 33

In article <9105120711.AA01176@>, brad@lsr-vax.UUCP (Brad J Zoltick) writes:
> 
> Has anyone had difficulty getting a SGI yp client
> to work with a Sun yp master when a router is involved
> on the subnet?  
> 
> We have no problems with Sun yp clients working in the
> same subnet. However, I can not get ypbind running on a SGI
> machine to connect to a ypserver on the subnet when a router
> is involved.  

If the router is between the client and the server, then you don't have much
hope, at least until the next release.  This is because NIS (gotta keep
those lawyers and PTT's happy) uses UDP/IP broadcasts for ypbind on
the client to find servers.  Broadcasts are not forwarded by routers.  You
can often get things working for a while by explicitly pointing the client
to the server with the `ypset` command.  (You'll need to use an IP number
or some other non-NIS way to resolve the server hostname.)  Unfortunately,
if the NIS server router, network, or whatever hiccups, your ypbind will
become unbound and your machine will be unhappy.

I've proposed more than once using IGMP multicast for discovering YP
servers.  If routers were routing IGMP (IRIS's do now, and dedicated
routers will as well with the advent of OSPF), then multicast would be a
near perfect solution.  Unfortunately, no other company seems to care, and
especially not the main company that would have to be convinced.

The next SGI release may have a mechanism for telling ypserv to bind to a
pre-specified ypserv and to never unbind.  Until then, your best bet might
be to make the isolated client into a slave-server.


Vernon Schryver,   vjs@sgi.com