Classical IP and ARP over ATM
RFC 2225

Network Working Group                                        M. Laubach
Request for Comments: 2225                                  Com21, Inc.
Category: Standards Track                                    J. Halpern
Obsoletes: 1626, 1577                          Newbridge Networks, Inc.
                                                             April 1998

                     Classical IP and ARP over ATM

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (1998).  All Rights Reserved.

Table of Contents

   1. ABSTRACT  . . . . . . . . . . . . . . . . . . . . . . . . . .  2
   2. ACKNOWLEDGMENT  . . . . . . . . . . . . . . . . . . . . . . .  2
   3. CONVENTIONS . . . . . . . . . . . . . . . . . . . . . . . . .  3
   4. INTRODUCTION  . . . . . . . . . . . . . . . . . . . . . . . .  3
   5. IP SUBNETWORK CONFIGURATION . . . . . . . . . . . . . . . . .  6
   5.1  Background  . . . . . . . . . . . . . . . . . . . . . . . .  6
   5.2  LIS Configuration Requirements  . . . . . . . . . . . . . .  7
   5.3  LIS Router Additional Configuration . . . . . . . . . . . .  8
   6. IP PACKET FORMAT  . . . . . . . . . . . . . . . . . . . . . .  8
   7. DEFAULT VALUE FOR IP MTU OVER ATM AAL5  . . . . . . . . . . .  9
   7.1  Permanent Virtual Circuits  . . . . . . . . . . . . . . . .  9
   7.2  Switched Virtual Circuits . . . . . . . . . . . . . . . . .  9
   7.3  Path MTU Discovery Required . . . . . . . . . . . . . . . . 11
   8. LIS ADDRESS RESOLUTION SERVICES . . . . . . . . . . . . . . . 11
   8.1  ATM-based ARP and InARP Equivalent Services . . . . . . . . 11
   8.2  Permanent Virtual Connections . . . . . . . . . . . . . . . 12
   8.3  Switched Virtual Connections  . . . . . . . . . . . . . . . 12
   8.4  ATMARP Single Server Operational Requirements . . . . . . . 13
   8.5  ATMARP Client Operational Requirements  . . . . . . . . . . 14
   8.5.1  Client ATMARP Table Aging . . . . . . . . . . . . . . . . 16
   8.5.2  Non-Normal VC Operations  . . . . . . . . . . . . . . . . 17
   8.5.3  Use of ATM ARP in Mobile-IP Scenarios . . . . . . . . . . 17
   8.6  Address Resolution Server Selection . . . . . . . . . . . . 17
   8.6.1  PVCs to ATMARP Servers  . . . . . . . . . . . . . . . . . 18
   8.7  ATMARP Packet Formats . . . . . . . . . . . . . . . . . . . 18

Laubach & Halpern           Standards Track                     [Page 1]
RFC 2225                  IP and ARP over ATM                 April 1998

   8.7.1  ATMARP/InATMARP Request and Reply Packet Formats  . . . . 18
   8.7.2  Receiving Unknown ATMARP packets  . . . . . . . . . . . . 20
   8.7.3  TL, ATM Number, and ATM Subaddress Encoding . . . . . . . 20
   8.7.4  ATMARP_NAK Packet Format  . . . . . . . . . . . . . . . . 21
   8.7.5  Variable Length Requirements for ATMARP Packets . . . . . 21
   8.8  ATMARP/InATMARP Packet Encapsulation  . . . . . . . . . . . 22
   9. IP BROADCAST ADDRESS  . . . . . . . . . . . . . . . . . . . . 23
   10. IP MULTICAST ADDRESS . . . . . . . . . . . . . . . . . . . . 23
   11. SECURITY CONSIDERATIONS  . . . . . . . . . . . . . . . . . . 23
   12. MIB SPECIFICATION  . . . . . . . . . . . . . . . . . . . . . 24
   13. OPEN ISSUES  . . . . . . . . . . . . . . . . . . . . . . . . 24
   14. REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . 24
   15. AUTHORS' ADDRESSES . . . . . . . . . . . . . . . . . . . . . 26
   APPENDIX A - Update Information  . . . . . . . . . . . . . . . . 27
   FULL COPYRIGHT STATEMENT . . . . . . . . . . . . . . . . . . . . 28

1.  ABSTRACT

   This memo defines an initial application of classical IP and ARP in
   an Asynchronous Transfer Mode (ATM) network environment configured as
   a Logical IP Subnetwork (LIS) as described in Section 5.  This memo
   does not preclude the subsequent development of ATM technology into
   areas other than a LIS; specifically, as single ATM networks grow to
   replace many Ethernet local LAN segments and as these networks become
   globally connected, the application of IP and ARP will be treated
   differently.  This memo considers only the application of ATM as a
   direct replacement for the "wires" and local LAN segments connecting
   IP end-stations ("members") and routers operating in the "classical"
   LAN-based paradigm.  Issues raised by MAC level bridging and LAN
   emulation are beyond the scope of this paper.

   This memo introduces general ATM technology and nomenclature.
   Readers are encouraged to review the ATM Forum and ITU-TS (formerly