Subject: Re: (ION) ILMI-Based Server Discovery (fwd)

From: "Ralph E. Droms" <[email-masked]>
Date: Mon, 9 Nov 1998 17:16:48 -0500 (EST)

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Tim,

> I have a few general questions about the ILMI-Based Server Discovery
> drafts.  Perhaps, the answers are obvious to some, but...
> 
> o	The ATMARP draft states "...it is impossible to implement
> 	a diskless host [that has only an ATM interface] to use ATMARP
> 	since local configuration is required [namely, the ATM address of
> 	the ATMARP server and perhaps its LIS address and subnet mask].
>
> 	How will a diskless host (with only an ATM interface) configure
> 	its IP address?

The comment is generic to atm-attached hosts and not specific to atmarp.
Perhaps it would be clearer to state that it is not possible to support
a diskless, atm-attached host given the current ip-over-atm services
standardized by the ietf (atmarp, mars and nhrp)

As to how server discovery will allow a diskless host to learn it's ip
address, there are several ways. A few are:

    o  Use server discovery to locate a mars then broadcast a dhcp 
       request using mars,

    o  Use server discovery to connect to an atmarp server, then 'broadcast'
       the dhcp request on 'all existing VCs' (This assumes the box upon
       which the atmarp server is running can either process the dhcp 
       request directly or forward it to a box that can. Both assumptions
       are met by many existing products today.)

    o  Use server discovery to look up the dhcp server address then send the
       dhcp request directly to the dhcp server. This would require a service
       registry oid for dhcp, but the server discovery mechanism should work
       fine.

Undoubtably there are other ways to use server discovery to support 
atm-attached diskless hosts. And, of course, there are non-server discovery
methods as well.

> o	What role ought DHCP have in ATM networks?  If DHCP works
> 	in ATM networks, shouldn't hosts use DHCP to retrieve their
> 	configuration parameters, including ATMARP, MARS and NHRP
> 	server addresses?

There needs to be a mechanism to learn the nsap for the dhcp server
in order to use dhcp to boot a diskless, atm-attached host. Server 
discovery could do this. Other mechanisms could do this also.

> o	Note the rather odd interaction between ATMARP and ATMDHCP...

I'm not familiar with 'ATMDHCP'. Is there a draft for this? 

cheers,
Mike

> 	Title		: ILMI-Based Server Discovery for ATMARP
> 	Filename	: draft-ietf-ion-discov-atmarp-02.txt
> 	
> 	Title		: ILMI-Based Server Discovery for MARS
> 	Filename	: draft-ietf-ion-discov-mars-02.txt
> 	
> 	Title		: ILMI-Based Server Discovery for NHRP
> 	Filename	: draft-ietf-ion-discov-nhrp-02.txt
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From: "Ralph E. Droms" <[email-masked]>
Date: Wed, 11 Nov 1998 11:46:19 -0500 (EST)

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Tim,

in order to find out who your DHCP server is one can also
use PAR from the ATM Forum. The Spec ist almost finished.

Patrick

Tim Salo wrote:
> -tjs

--
  Dr. Patrick Droz                | [email-masked]  
  IBM Zurich Research Laboratory  | http://www.zurich.ibm.com/~dro 
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