Classical IP to NHRP Transition (RFC2336)
Original Publication Date: 1998-Jul-01
Included in the Prior Art Database: 2000-Sep-13
Internet Society Requests For Comment (RFCs)
This document describes methods and procedures for the graceful transition from an ATMARP LIS to an NHRP LIS network model over ATM.
Network Working Group J. Luciani
Request for Comments: 2336 Bay Networks
Category: Informational July 1998
Classical IP and ARP over ATM to NHRP Transition
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright (C) The Internet Society (1998). All Rights Reserved.
This document describes methods and procedures for the graceful
transition from an ATMARP LIS to an NHRP LIS network model over
The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD,
SHOULD NOT, RECOMMENDED, MAY, and OPTIONAL, when they appear in this
document, are to be interpreted as described in .
ATMARP defines an initial application of classical IP and ARP in an
ATM network environment configured as a LIS. ATMARP only
considers application of ATM as a direct replacement for the "wires"
and local LAN segments connecting IP end-stations and routers
operating in the "classical" LAN-based paradigm.
The NBMA Next Hop Resolution Protocol (NHRP) allows a source station
(a host or router), wishing to communicate over a Non-Broadcast,
Multi-Access (NBMA) subnetwork, to determine the internetworking
layer addresses and NBMA addresses of suitable "NBMA next hops"
toward a destination station. If the destination is connected to the
NBMA subnetwork and direct communication is administratively allowed,
then the NBMA next hop is the destination station itself. Otherwise,
the NBMA next hop is the egress router from the NBMA subnetwork that
is "nearest" to the destination station. For the purposes of this
document, the NBMA network is of type ATM.
It is reasonable to expect that ATMARP Clients and NHRP Clients will
initially coexist within a LIS. Thus, it is necessary to define a
graceful transition, including a period of coexistance, from the use
of ATMARP to the use of NHRP for address resolution in the LIS
. In short, NHSs will be required to respond to ATMARP Client
queries in a fashion which will permit continued use of the ATMARP
Client within the LIS during the ATMARP to NHRP transition period.
Note that this document places no protocol requirements upon
For the following, it will be assumed that the reader is familiar
with the terminology as described in .
2. Service Requirements
If NHRP is to be used in a LIS then only NHSs will be used in the
LIS; that is, there will not be a mixture of NHSs and ATMARP servers
within the same LIS. Since ATMARP servers will not be able to
understand NHCs and since, as described below, NHSs will respond to
ATMARP Clients, this is a reasonable simplifying restriction.
This document will only address SVC based environments and w...