[comp.protocols.appletalk] KIP/K-Star

aks@hydra.ucsb.edu ( ) (09/20/88)

I would like to understand why (apparently both) KIP and K-Star do not
support the ability to treat the Localtalk network as an IP subnet AND
provide the directed, encapsulated IP feature?  It seems that you can
treat the Localtalk network as an IP subnet, while not having the
capability of encapsulating Localtalk packets and directing them to
another Kbox across a router, *or* you can treat the Localtalk network
as an extension of the SAME subnet on which the Kbox resides (with
either static or dynamic, serialized IP address assignment), while
obtaining encapsulated Localtalk packets.  Is this a correct assesment? 

Here's a grahic example of a small piece of our network:

		     Enet 254
	       ------------------------
		 | 		|
		[gw]           [gw]
		 |       	|
	         |           ---------
		 |              |
	         |	       [gw]
         ENet 24 |	ENet 88 |
	    --------	    ---------
		|		  |
	     [Kbox1]           [Kbox2]
		|		  |
	   ==========        ===========
	   |  |  |	      |   |   |
	 Mac Mac LW	     Mac Mac  LW

As you can see, Kbox1 and KBox2 are seperated by several gateways and
subnets; also, (it's not evident but) Enet 24 is very crowded -- we
don't want the Mac's in ATNet 26 to be part of ENet 24 -- our host
address are named, centrally administrated and statically allocated. 
Similarly, the Macs in ATNet 90 do not really need to be in ENet 88. 
Yet, if we want to make the two Zones "see" each other, we must run the
KIP or KStart software which doesn't allow the two modes to mix.  Or am
I wrong (I hope, I hope)? 

You see, if you are trying to fit one or more potentially large
Localtalk networks into some fairly well-occupied subnets, it is very
difficult to find blocks of sequential addresses to assign to each
Localtalk network.  Moreover, once you accomplish this, it becomes very
difficult to then later expand the Localtalk networks with more IP
addresses.  To me, the ideal would be to have each Localtalk network
treated as a subnet, with its own host address range, yet also very
desireable to be able to direct encapsulated Localtalk packets to
another Kbox. 

I realize there is a "klugey" way of accomplishing my goals: I can use ARP
subnetting, which is where a gateway (or host running "proxyarp") is
defined with multiple interface addresses, such that the same physical
media is carrying two subnets, thus logically separating the machines.  It
is true that I have done this with one of our Localtalk networks, in order
to "test" the KStar software, which we seem to have running sucessfully.
However, I do not find it at all desireable to continue this practice, nor
can I really recommend it to other campus departments as they may not have
gateways as configurable as ours, nor proxyarp, nor have the technical
expertise to keep it running happily.  I would really like to have both
features.

Does anyone else consider this to be a problem also?  Does anyone know if
there is a "fix" planned, or knows how one can be made?  I can hack the
code myself, if given a pointer.

Thanks for any sympathy or advice.

Alan Stebbens
Manager, CCSE
University of California, Santa Barbara
ARPA: aks@hub.ucsb.edu
UUCP: ucbvax!ucsbcsl!aks
805-961-3221

Alan Stebbens (aks@hub.ucsb.edu)

ddl@husc6.harvard.edu (Dan Lanciani) (09/21/88)

In article <858@hub.ucsb.edu>, aks@hydra.ucsb.edu ( ) writes:
> I would like to understand why (apparently both) KIP and K-Star do not
> support the ability to treat the Localtalk network as an IP subnet AND
> provide the directed, encapsulated IP feature?

	I made some changes to KIP to allow the LocalTalk segment to
be an ip subnet rather than an extension of the ethernet that the Kbox
is on.  The ip address of the subnet is read from the atalkatab database
in one of the "spare" fields.  There are some limitations.  First,
the KIP code seems to like 8 bits of host and I made no attempt to fight
this trend.  If you have a net mask of other than 255.255.255.0 you
will have problems.  Second, I didn't fix ip routing itself to understand
subnets, so proxy arp from other gateways on a backbone would still be
required.  (I think someone else has fixed this, but it was unnecessary
for us since our gateways need to do proxy arp anyway.)  The Kbox
will, in turn, do proxy arp for its own subnet.  If this isn't clear,
think of the Kbox as a gateway that knows the subnet of its LocalTalk
cable but assumes that all other subnets are directly connected to
its ethernet interface.  Third, I did not add a RIP process to
KIP (and it may well not fit) so you need to run a RIP spoofer on
some other host so that hosts that *do* understand subnets will
route to the Kbox.  If this sounds useful given all the stated
restrictions, I will make it available.

				Dan Lanciani
				ddl@harvard.*

minshall@kinetics.UUCP (Greg Minshall) (09/26/88)

From article <858@hub.ucsb.edu>, by aks@hydra.ucsb.edu ( ):
> I would like to understand why (apparently both) KIP and K-Star do not
> support the ability to treat the Localtalk network as an IP subnet AND
> provide the directed, encapsulated IP feature?  It seems that you can
> treat the Localtalk network as an IP subnet, while not having the
> capability of encapsulating Localtalk packets and directing them to
> another Kbox across a router, *or* you can treat the Localtalk network
> as an extension of the SAME subnet on which the Kbox resides (with
> either static or dynamic, serialized IP address assignment), while
> obtaining encapsulated Localtalk packets.  Is this a correct assesment? 

It is true that with K-STAR (and KIP), one uses up IP address space from
the ethernet side of the FastPath in order to provide IP addresses for
Macs on the LocalTalk side.

This is somewhat of a problem in certain cases (such as yours).

The thing that makes it hard to do what you want in the FastPath 4 (and
this problem essentially correlates to engineering hours) is that K-STAR
does not provide all the functions of an IP router.  In particular, K-STAR
does not have any means of sharing with other hosts and routers that it
is a path to IP subnet "X".  (If K-STAR were to do this, it would probably
use RIP, the protocol which Berkeley 4.x machines speak [as well as a
substantial number of other entities including most "real" IP routers].)
Since we don't tell anyone how to get to IP subnet "X", an installation
need to set up default routes (or at least one) to IP subnet "X".

This capability IS on a list of things to do to the K-STAR code, but there
is no specific date or time associated with it.  Your best bet is to inform
your sales rep at Kinetics (or the dealer you purchase through) about your
needs.

Greg Minshall
...ucbvax!unisoft!kinetics!minshall		(415)947-0998

jwk@SCRIPPS.EDU ("Two Sheds" Kupec) (09/01/89)

Una pregunta:

I want to run CAP, among other things.  For such a purpose, are
KIP and K-Star 7.0 essentially the same?  Which would you recommend?
I haven't seen- especially in the FastPath 4 docs- what exactly K-Star 
7.0 can do for me.  I am using K-Star 7.0 right now in my FastPath 4 but
I'm simply using NCSA Telnet 2.3 on the LocalTalk side for telnet/ftp
between Mac's and Ethernet hosts.  Any and (almost all) comments will be 
appreciated.

Thanks in advance,

John W. Kupec	(jwk@scripps.edu)
Programmer/Analyst
Scripps Research Foundation
Dept. of Molecular Biology