From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc1132.txt | 227 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 227 insertions(+) create mode 100644 doc/rfc/rfc1132.txt (limited to 'doc/rfc/rfc1132.txt') diff --git a/doc/rfc/rfc1132.txt b/doc/rfc/rfc1132.txt new file mode 100644 index 0000000..3c56384 --- /dev/null +++ b/doc/rfc/rfc1132.txt @@ -0,0 +1,227 @@ + + + + + + +Network Working Group L. McLaughlin III +Request for Comments: 1132 The Wollongong Group + November 1989 + + + 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 [1] + packets on networks supporting Novell's Internet Packet Exchange + Protocol [2] (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. + +Introduction + + The goal of this specification is to allow compatible and + interoperable implementations for transmitting Internet packets such + as the Internet Protocol [3] (IP) and Address Resolution Protocol [4] + (ARP) as well as the Connectionless-mode Network Protocol [5] (CLNP) + over IPX networks. + + IPX is a proprietary standard developed by Novell derived from + Xerox's Internet Datagram Protocol [6] (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 [7]. This + document will focus on the implementation of that RFC over IPX + networks. + +Description + + In general, this specification allows IPX networks to be used to + support any network protocol which can use the IEEE 802.2 Data Link + Layer specification. + + 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. + + + + +McLaughlin [Page 1] + +RFC 1132 802.2 Packets over IPX Networks November 1989 + + +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. + +Address Mappings + + 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. + +Byte Order + + The byte transmission order is "big-endian" [8]. + +Broadcast Addresses + + 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 field to 0xffffff, and the Immediate + Address field of the IPX Event Control Block to 0xffffff. + +Unicast Addresses + + IPX packets may be unicast by setting the IPX header Packet Type + field to 0x04, the Destination Network field and Destination Node + field to those values found by address resolution, and the Immediate + Address field of the IPX Event Control Block to the physical address + of the destination node or the appropriate IPX bridge. + +Checksum + + Like most IPX applications, this specification does not use IPX + checksum. + +Reserved values + + The IPX socket 0x8060 has been reserved by Novell for the + implementation of this protocol. + +Implementation + + The encapsulation of Internet packets within IPX networks has proved + to be quite useful. Because the IPX interface insulates knowledge of + + + +McLaughlin [Page 2] + +RFC 1132 802.2 Packets over IPX Networks November 1989 + + + the physical layer from an application, 802.2 over IPX networks work + over any physical medium. A typical IP over IPX packet is shown + below: + + -------------------- + N bytes | physical header | + |------------------| + 30 bytes | IPX header | + |------------------| + 8 bytes | 802.2 header | + |------------------| + usually 20 bytes | IP header | + |------------------| + usually 20 bytes | TCP header | + |------------------| + up to 498 bytes | TCP data | + -------------------- + + On workstations supporting an IPX programming interface, + implementation of this specification has proved fairly + straightforward. The only change which was done was to modify the + existing address resolution protocol code to allow for cache entries + larger than the hardware address length. This was done to allow room + for the immediate address of a possible intervening IPX bridge in + addition to the destination node and network addresses to be + associated with a given IP address. + + Thus far, no implementations have been attempted on systems which do + not already support an IPX programming interface (e.g., a dedicated + router) though a few implementation details can be noted. First, + obviously any such implementation will have to distinguish IPX + packets from other packets; this process will be media dependent. + Second, note that no unicast packet is ever sent from host1 to host2 + without a prior broadcast packet from host2 to host1. Thus, the + immediate address of a possible intervening IPX bridge between host1 + and host2 can be learned from the physical header of that prior + broadcast packet. Third, any such implementation will need to + discover the local IPX network number from a Novell bridge or file + server. The mechanisms for doing this exist but documentation for + their use is not commonly available. + +References + + [1] IEEE, "IEEE Standards for Local Area Networks: Logical Link + Control", IEEE, New York, 1985. + + [2] Novell, Inc., "Advanced NetWare V2.1 Internetwork Packet Exchange + Protocol (IPX) with Asynchronous Event Scheduler (AES)", October + + + +McLaughlin [Page 3] + +RFC 1132 802.2 Packets over IPX Networks November 1989 + + + 1986. + + [3] Postel, J., "Internet Protocol", RFC-791, USC/Information + Sciences Institute, September 1981. + + [4] Plummer, D., "An Ethernet Address Resolution Protocol", RFC-826, + November 1982. + + [5] ISO DIS 8473: "Information Processing Systems - Data + Communications - Protocol for Providing the Connectionless-mode + Network Service". + + [6] Xerox Corporation, "Xerox Network Systems Architecture", XNSG + 068504, April 1985. + + [7] Postel, J., and J. Reynolds, "A Standard for the Transmission of + IP Datagrams over IEEE 802 Networks", RFC-1042, USC/Information + Sciences Institute, February 1988. + + [8] Cohen, D., "On Holy Wars and a Plea for Peace", Computer, IEEE, + October 1981. + +Security Considerations + + Security issues are not addressed in this memo. + + +Author's Address: + + Leo J. McLaughlin III + The Wollongong Group + 1129 San Antonio Road + Palo Alto, CA 94303 + + Phone: (415) 962-7100 + + EMail: ljm@TWG.COM + + + + + + + + + + + + + + +McLaughlin [Page 4] + \ No newline at end of file -- cgit v1.2.3