Standard for the transmission of 802.2 packets over IPX networks (RFC1132)
Original Publication Date: 1989-Nov-01
Included in the Prior Art Database: 2000-Sep-12
Internet Society Requests For Comment (RFCs)
The goal of this specification is to allow compatible and interoperable implementations for transmitting Internet packets such as the Internet Protocol  (IP) and Address Resolution Protocol  (ARP) as well as the Connectionless-mode Network Protocol  (CLNP) over IPX networks.
Network Working Group L. McLaughlin III
Request for Comments: 1132 The Wollongong Group
A Standard for the Transmission of 802.2 Packets over IPX Networks
Status of this Memo
This document specifies a standard method of encapsulating 802.2 
packets on networks supporting Novell's Internet Packet Exchange
Protocol  (IPX). It obsoletes earlier documents detailing the
transmission of Internet packets over IPX networks. It differs from
these earlier documents in that it allows for the transmission of
multiple network protocols over IPX and for the transmission of
packets through IPX bridges. Distribution of this memo is unlimited.
The goal of this specification is to allow compatible and
interoperable implementations for transmitting Internet packets such
as the Internet Protocol  (IP) and Address Resolution Protocol 
(ARP) as well as the Connectionless-mode Network Protocol  (CLNP)
over IPX networks.
IPX is a proprietary standard developed by Novell derived from
Xerox's Internet Datagram Protocol  (IDP). Defining the
encapsulation of the IEEE 802.2 Data Link Layer Standard over IPX in
terms of yet another 802.X Physical Layer standard allows for the
transmission of IP Datagrams as described in RFC 1042 . This
document will focus on the implementation of that RFC over IPX
In general, this specification allows IPX networks to be used to
support any network protocol which can use the IEEE 802.2 Data Link
More specifically, IPX networks may be used to support IP networks
and subnetworks of any class. By encapsulating IP datagrams within
IPX datagrams and assigning IP numbers to the hosts on a IPX network,
IP-based applications are supported on these hosts. The addition of
an IP Gateway capable of encapsulating IP packets within 802.IPX
datagrams would allow those hosts on an IPX network to communicate
with the Internet.
Maximum Transmission Unit
The maximum data size of a IPX datagram is 546 bytes. As the
combined size of the 802.2 LLC and SNAP headers is 8 bytes, this
results in a Maximum Transmission Unit (MTU) of 538 bytes.
The mapping of Internet Protocol addresses to 802.IPX addresses is
done using the Address Resolution Protocol in the same fashion as
with other IEEE 802.X physical addresses. However, the length of an
802.IPX physical address is 10 bytes rather than 2 or 6. This 10
byte physical address consists of the 4 bytes of the IPX network
address followed by the 6 bytes of the IPX node address.
The byte transmission order is "big-endian" .
IPX packets may be broadcast by setting the IPX header Packet Type
field to 0x14, the Destination Network field to the local network
number, the the Destination Node...