This document is obsolete. Please
refer to RFC 1420.
Network Working Group R. Wormley Request for Comments: 1298 S. Bostock Novell, Inc. February 1992
SNMP over IPX
Status of this Memo
This memo provides information for the Internet community. It does not specify an Internet standard. Distribution of this memo is unlimited.
Abstract
This memo defines a convention for encapsulating Simple Network Management Protocol (SNMP) [1] packets over the transport mechanism provided via the Internetwork Packet Exchange (IPX) protocol [2].
Editor's Note
As stated below and in reference [5], it is strongly advised that for interoperability, SNMP be implemented over UDP/IP and not directly on media or other protocols (such as IPX).
The SNMP protocol has been specified as the official network management protocol of the Internet. Its widespread acceptance and implementation by developers, both inside and outside the Internet community, is fostering synergetic growth to a variety of protocols and platforms.
This memo addresses the use of SNMP over the IPX protocol, which has become quite widespread principally due to the popularity of Novell NetWare. Roughly equivalent to UDP in function, IPX provides connectionless, unacknowledged datagram service over a variety of physical media and protocols.
Although modifications have been made elsewhere in the NetWare protocol suite, IPX is identical to the Xerox Internet Datagram Protocol (IDP) [3]. The socket address space authority is administered by Novell.
The use of SNMP over the UDP transport [4] is today the common mode of operation in the Internet. This specification may be appropriate for some environments in which UDP transport services are not
Wormley & Bostock [Page 1]
RFC 1298 SNMP over IPX February 1992
available. SNMP implementors should be aware that the choice of underlying transport may have a significant impact on the interoperability and ubiquity of the management capability in the Internet. Considerations relevant to choosing a transport for use with SNMP are described in [5].
SNMP protocol entities will receive GetRequest-PDU, GetNextRequest- PDU, and SetRequest-PDU messages on socket 36879 (Destination Socket field set to hexadecimal 900F), and Trap-PDU messages on socket 36880 (Destination Socket field set to hexadecimal 9010).
GetResponse-PDU messages will be addressed to the IPX address and socket from which the corresponding GetRequest-PDU, GetNextRequest- PDU, or SetRequest-PDU originated.
Although SNMP does not require conformant implementations to accept messages whose length exceed 484 bytes, it is recommended that implementations support a maximum SNMP message size of 546 bytes (the maximum size allowed under IPX). Furthermore, this limit is the maximum packet length guaranteed to traverse IPX routers which do not provide fragmentation. Implementors may choose to use longer packet lengths if the maximum is known, which depends on the intermediate routers and/or intermediate datalink layer protocols.
The agent-addr field in a Trap-PDU emitted by an SNMP agent should contain the IpAddress 0.0.0.0. An SNMP manager may ascertain the source of the trap by querying the transport layer.
There are occasions when it is necessary to represent a transport service address in a MIB. For instance, the SNMP party MIB [6] uses an OBJECT IDENTIFIER to define the transport domain (IP, IPX, etc.) and an OCTET STRING to represent an address within that domain. The following definitions are provided for use in such a scheme.
-- A textual convention denoting a transport service address in -- the ipxTransportDomain. An IpxTransportAddress is 12 octets -- long and comprises 3 fields, each in network-byte (high-low) -- order.
-- The first field is 4 octets long and contains the network -- number.
-- The next field is 6 octets long and contains the physical -- address of the node. Since IPX can run over a variety of -- subnet architectures, the physical node address may not -- require all 6 octets. As specified in [2], the physical -- node address will occupy the least significant portion of -- the field and the most significant octets should be set -- to zero.
-- The last field is 2 octets long and contains the socket -- number.
[1] Case J., Fedor M., Schoffstall M., and J. Davin, "A Simple Network Management Protocol (SNMP)", RFC 1157, SNMP Research, Performance Systems International, Performance Systems International, and MIT Laboratory for Computer Science, May 1990.
[2] Novell, Inc., "NetWare System Technical Interface Overview", June 1989.
[3] Xerox System Integration Standard, "Internet Transport Protocols", XSIS 028112, Xerox Corporation, December 1981.
[4] Postel, J., "User Datagram Protocol," RFC 768, USC/Information Sciences Institute, 28 August 1980.
[5] Kastenholz, F., "SNMP Communications Services," RFC 1270, Clearpoint Research Corporation, October 1991.
[6] McCloghrie, K., Davin, J., and J. Galvin, "Definitions of Managed Objects for Administration of SNMP Parties", RFC in preparation.