SUMMARY : Running NIS (YP) in a heterogenous environment

From: Fran Sullivan (fmrco!stowe!
Date: Wed Aug 28 1991 - 18:59:03 CDT


> We are currently running YP in a Sun environment. We are considering moving our
> YP master from a Sun to a DECstation, then making the Sun a YP slave.
> Are there any problems or caveats in doing this ? I thought I had seen
> there may be some inconsistancies in Sun and DEC's
> YP implementation and wanted to find out if anyone else has a mixed YP
> environment, and what (if any) problems they've encountered.

Well .... It looks like the WORST thing I can do, is make a DECstation the
          yp master. For now things will be status quo, A Sun as the master,
          and a DECstation slave. Replies to the question follow.



Aydin Edguer <uunet!!edguer>

Don't do it.

DEC has a number of nice features.
You can limit which NIS servers a ypbind will talk with on the command line.
You can specify how a server gets its information (NIS/BIND/KERBEROS).

But don't make a DEC server information to a Sun if you are attached
to the Internet. This is because Sun's ypserv must be configured to
ask the nameserver when required. DEC's ypserv will not. You use
the svcorder file to specify the local behavior, but it does not affect
the ypserver. Thus Suns will not be able to get the answers they need.


Hal Pomeranz <uunet!!pomeranz>

If you are doing DNS resolution via YP, then making the DEC your YP
master will screw you up. Sun puts a special flag in its hosts.*
maps to indicate that a DNS query should be made if the host does not
appear in the map file. Unfortunately, no other vendor uses this hack,
so if the DEC machine becomes the YP master then your Sun hosts won't
do DNS lookups.


Jon A. Tankersley <uunet!!zjat02>

Depending on the OS release of the Sun there may be LOTS of problems. It is
generally better to let the Sun run YP/NIS and make the Sun with the highest
OS rev be the master.


Shilo Jennings <uunet!!shilo>

AAACCCHHHH. Don't do this!!! Keep the Sun as the MASTER, use the dec as
slave/clients only. We currently have about 150 workstations, including
a smattering of DEC, MIPS, IBM RICS, sun4, and 386i's. This works great,
as long as Sun is the master. Sun's NIS implementation is much more thorough
and cleaner, including additional maps that dec does not have as a master,
but will support as a slave.


Brian Keves - Consultant <uunet!!keves>

When I was running both a SUN and DEC environment on one network I actually
kept two YP domains, one for each environment, and then shared the crucial

There definitely are problems with what you suggest. SunOs and Ultrix definitely
have different YP maps that they support. I decided not to spend the time
trying to make them ultra compatible and just kept the two domains.

Common information can be shared between two domains.


Gilbert E. Detillieux <uunet!silver.cs.UManitoba.CA!gedetil>

I'm really behind on sun-nets, as I was on holidays. I didn't see a summary
posted, so I assume you're still looking for info.

We _had_ a DEC running Ultrix as the YP master, and changed over to a Sun,
because of a problem we had, not with NIS (YP) itself, but with it's
interaction with DNS. Here's the problem, in a nutshell.

Sun: Clients needing host info look up /etc/hosts, or call up YP if it's
up. If the YP map doesn't have the required entry, and DNS is available,
the ypserv process calls the DNS resolver and returns a faked up YP record
to the client.

DEC (and others): Clients decided by some means whether to use /etc/hosts,
YP, and/or DNS, and in what sequence. If the YP server doesn't give them
the record they need, it's up to them to call the DNS resolver.

So, Sun clients calling a DEC YP server will never get DNS entries back. A
way around this is to get, from Sun, an altered version of the C library
which will make use of DNS directly. We've never tried this, and chose
instead to have our YP master (& slaves) running on Suns.

Thanks to all who replied.

* Fran Sullivan | |
* fmrco! | |
* Sun Tech Support | (o) (o)
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