Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!samsung!usc!ucsd!helios.ee.lbl.gov!me10.lbl.gov!milburn
From: milburn@me10.lbl.gov (John Milburn)
Newsgroups: comp.sys.hp
Subject: Re: Booting discless over multiple LANs
Message-ID: <4768@helios.ee.lbl.gov>
Date: 4 Feb 90 17:45:50 GMT
References: <1720001@hpbbi4.HP.COM>
Sender: usenet@helios.ee.lbl.gov
Reply-To: JEMilburn@lbl.gov (John Milburn)
Organization: Lawrence Berkeley Laboratory, Berkeley, CA
Lines: 29
X-Local-Date: 4 Feb 90 09:45:50 PST

In article <1720001@hpbbi4.HP.COM> markl@hpbbi4.HP.COM (#Mark Lufkin) writes:
>	This is a well known feature of the HPUX discless. The point is that
>	when your system boots, it does a broadcast. If there happens to be
>	a gateway or router or whatever between your two LANs then the
>	message will not be passed across.

I think you are missing the point somewhat, Mark.  The discless
machine does indeed broadcast, but the server is the router,
so it picks up the broadcast.  It just doesn't respond.

The problem is that the server machine is unable to serve clients on
two networks, even if the server has direct interfaces to both
networks.  This is somewhat limiting.

>       [...] Another point is that it is not a good idea to
>	boot across the backbone LAN as this will cause performance problems -
>	swapping on the LAN, file system transfers and broadcasts (well, 
>	multicasts really).

This is entirely dependent on the site.  A well designed Ethernet can
handle quite a few discless machines without severe performance
penalty.  Hell, our backbone traffic consists mostly of LAVC (Local
Area Vax Cluster) traffic, even with tens of discless clients on the
main net.  All of this traffic is minimized by intelligent placement
of LanBridges.
John Milburn - Advanced Light Source - Lawrence Berkeley Laboratory
INTERNET: JEMilburn@lbl.gov   BITNET:    JEMilburn@LBL.bitnet
UUCP:      {...}!ucbvax!lbl.gov!JEMilburn
SnailMail: 1 Cyclotron Road 46-161 Berkeley, Ca. 94720  Ph:  (415) 486-6969