RFC 1419 (rfc1419) - Page 3 of 7

SNMP over AppleTalk

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RFC 1419                  SNMP over AppleTalk                 March 1993


   nbpZone corresponding to the nbpEntry with the nbpType equal to "SNMP
   Agent" should be included in the variable-bindings of any trap that
   is sent [3].

   The NBP name for both an agent and a trap handler should be stable -
   it should not change any more often than the IP address of a typical
   TCP/IP end system changes.  It is suggested that the NBP name be
   stored in some form of stable storage (PRAM, local disk, etc.).

3. Discussion of AppleTalk Addressing

3.1 Introduction

   The AppleTalk protocol suite has certain features not manifest in the
   standard TCP/IP suite.  Its unique naming strategy and the dynamic
   nature of address assignment can cause problems for SNMP management
   stations that wish to manage AppleTalk networks.  TCP/IP end nodes,
   as of this writing, have an associated IP address which distinguishes
   each from the other.  AppleTalk end nodes, in general, have no such
   characteristic.  The network level address, while often relatively
   stable, can change at every reboot (or more frequently).

   Thus, a thrust of this proposal is that a "name" (as opposed to an
   "address") for an end system be used as the identifying attribute.
   This is the equivalent, when dealing with TCP/IP end nodes, of using
   the domain name.  While the mapping (DNS name, IP address) is more
   stable than the mapping (NBP name, DDP address), the mapping (DNS
   name, IP address) is not required to exist (e.g., hosts with no host
   name, only an IP address). In contrast, all AppleTalk nodes that
   implement this specification are required to respond to NBP lookups
   and confirms (e.g., implement the NBP protocol stub), which
   guarantees that the mapping (NBP name, DDP address) will exist.

   In determining the SNMP name to register for an agent, it is
   suggested that the SNMP name be a name which is associated with other
   network services offered by the machine.  On a Macintosh system, for
   example, it is suggested that the system name (the "Macintosh Name"
   for System 7.0 which is used to advertise file sharing, program-to-
   program communication, and possibly other services) be used as the
   "object" field of the NBP name.  This name has AppleTalk
   significance, and is tightly bound to the network's concept of a
   given system's identity.

   NBP lookups, which are used to turn NBP names into DDP addresses, can
   cause large amounts of network traffic as well as consume CPU
   resources. It is also the case that the ability to perform an NBP
   lookup is sensitive to certain network disruptions (such as zone
   table inconsistencies, etc.) which would not prevent direct AppleTalk



Minshall & Ritter
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