Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!gp
From: gp@lll-lcc.aRpA (George Pavel)
Newsgroups: comp.protocols.appletalk
Subject: Re: the FastPath dilemma
Message-ID: <1421@lll-lcc.aRpA>
Date: 5 Jan 88 23:05:59 GMT
References: <8801042306.AA24931@cs.utah.edu>
Organization: Lawrence Livermore Labs, Livermore Ca
Lines: 26

in article <8801042306.AA24931@cs.utah.edu>, crum@CS.UTAH.EDU (Gary L. Crum) says:
> 
> Neither KIP nor the Kinetics "combined" (EtherTalk&UDP routing) code seems
> to have all the answers when it comes to LocalTalk<->Ethernet bridging.
> ... 
> their VAX/VMS systems.  Utah has a class B Internet and wants to use 8 bits
> as a subnet number, but if each new LocalTalk network is assigned a full
> subnet (as we understand the Kinetics code requires), we will be wasting
> many IP addresses.  If you have thought about and solved problems like these,
> please share your experiences.
> 
We use the Kinetics combined gateway code.  It allows you to specify the
length and starting position in bits of the subnet address.  We have a class B
address and tend to assign 8 bit "subnets"  (we don't actually use subnets, but
we assign numbers as if we did).  We subdivided one of these "subnets" to be
half normal and half Kinetics by assigning a subnet mask of 9 bits starting at
bit 7 (the most significant bit of the least significant byte).  In particular,
addresses 128.115.21.1 through 128.115.21.127 are on the Ethernet side of the
Kinetics box, and 128.115.21.128 through 128.115.21.255 are on the Localtalk
side.  By setting the length and starting bit of the subnet mask appropriately
you could assign even smaller chunks to the Localtalk side.

George Pavel
Lawrence Livermore National Laboratory
P.O. Box 808  L-68				(was gp@lll-lcc.arpa)
Livermore, CA 94550			Internet: gp@lll-lcc.llnl.gov
(415)422-4262				UUCP: ihnp4!lll-lcc!gp