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diff --git a/doc/rfc/rfc2601.txt b/doc/rfc/rfc2601.txt new file mode 100644 index 0000000..bf2d485 --- /dev/null +++ b/doc/rfc/rfc2601.txt @@ -0,0 +1,339 @@ + + + + + + +Network Working Group M. Davison +Request for Comments: 2601 Cisco Systems +Category: Standards Track June 1999 + + + ILMI-Based Server Discovery for ATMARP + +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 (1999). All Rights Reserved. + +Abstract + + This memo defines how ILMI-based Server Discovery, which provides a + method for ATM-attached hosts and routers to dynamically determine + the ATM addresses of servers, shall be used to locate ATMARP servers. + +1. Introduction + + Presently, configuring a host or router to use ATMARP [1] is + cumbersome and error-prone since it requires at least one ATM address + to be statically configured on each host or router in the network. + Further, it is impossible to implement a diskless host to use ATMARP + since local configuration is required. ILMI-based Server Discovery, + hereafter referred to as "server discovery," provides a solution to + these problems. + + A brief overview of the Integrated Local Management Interface (ILMI) + and the Service Registry MIB, as defined by the ATM Forum, are + provided in this memo. The reader should consult [2] for a complete + description of ILMI and this MIB, but the information contained here + is sufficient for an understanding of its use to support ATMARP + server discovery. + +2. Integrated Local Management Interface + + The Integrated Local Management Interface (ILMI) [2] provides a + mechanism for ATM-attached devices, such as hosts, routers, and ATM + switches, to transfer management information. It is based on the + Simple Network Management Protocol (SNMP), Version 1, and supports + + + +Davison Standards Track [Page 1] + +RFC 2601 ILMI-Based Server Discovery for ATMARP June 1999 + + + get, get-next, set and trap operations. + + The ILMI specification designates the switch side of the ATM link as + the 'network side' and the host/router side of the ATM link as the ' + user side.' The Service Registry MIB, which is outlined in Section 3, + is implmented on the network side and is queried from the user side. + +3. ILMI 4.0 Service Registry MIB + + Server discovery utilizes the Service Registry MIB defined by the ATM + Forum in ILMI Specification Version 4.0 [2]. To support the existing + framework for IP over ATM, ATM switches must support the Service + Registry MIB. + + A row in the service registry table [2] is defined as: + + AtmfSrvcRegEntry ::= SEQUENCE { + atmfSrvcRegPort INTEGER, + atmfSrvcRegServiceID OBJECT IDENTIFIER, + atmfSrvcRegATMAddress AtmAddress, + atmfSrvcRegAddressIndex INTEGER, + atmfSrvcRegParm1 OCTET STRING + } + + The definition of each field in this structure is: + + atmfSrvcRegPort - The ATM port number for which this entry + contains management information. The value of zero may be used + to indicate the ATM interface over which a management request + was received. + + atmfSrvcRegServiceID - This is the service identifier that + uniquely identifies the type of service at the address + provided in the table. (See Section 3.2 for ATMARP OID.) + + atmfSrvcRegATMAddress - This is the full address of the service. + The ATM client will use this address to establish a connection + with the service. + + atmfSrvcRegAddressIndex - An arbitrary integer to differentiate + multiple rows containing different ATM addresses for the same + service on the same port. + + atmfSrvcRegParm1 - An octet string whose size and meaning is + determined by the value of atmfSrvcRegServiceID. + + The service registry table is indexed by atmfSrvcRegPort, + atmfSrvcRegServiceID and atmfSrvcRegAddressIndex. + + + +Davison Standards Track [Page 2] + +RFC 2601 ILMI-Based Server Discovery for ATMARP June 1999 + + +3.1 Service Parameter String + + A generic parameter string is defined in the service registry table, + thus allowing protocol-specific parameters to be specified. To be + consistent with [1], the parameter string for ATMARP shall be: + + ar$pro 16 bits Protocol type + ar$plen 8 bits Length of protocol address + ar$addr plen octets Network address + ar$mask plen octets Network mask + + Where + + ar$pro - see Assigned Numbers for protocol type number for + protocol using ATMARP. (IPv4 is 0x0800, IPv6 is 0x86DD) + + ar$plen - Length of the protocol address. (IPv4 is 4, IPv6 is 16) + + ar$addr - Network address represented in network byte order + + ar$mask - Network mask represented in network byte order + +3.2 Service Object Identifier + + This OID, assigned in the ATM Forum Service Registry MIB, names + ATMARP within the context of server discovery. + + atmfSrvcRegATMARP OBJECT IDENTIFIER ::= { 1.3.6.1.4.1.353.1.5.3 } + + It does not name any managed objects, rather is used to locate + appropriate rows in the service registery table. + +4. ATMARP Client Behavior + + An ATMARP client will access the service registry table via ILMI + using the SNMP GetNext operator to "sweep" (SNMP parlance for a + linear search) beginning with {Port = 0, ServiceID = <see Section + 3.2>, Index = 0} while holding the port number and the serviceID + constant. (Port number 0 is used within ILMI to indicate "this + port.") + + An ATMARP client with no local configuration, such as a diskless + workstation, must use the row with the lowest index value if multiple + ATMARP servers, possibly for multiple networks, are listed. + + ATMARP clients that have local IP configuration must use a row that + has the appropriate IP address. For example, consider the case where + an IP router has 3 logical interfaces defined on a single physical + + + +Davison Standards Track [Page 3] + +RFC 2601 ILMI-Based Server Discovery for ATMARP June 1999 + + + interface with IP addresses 1.0.0.1/8, 128.10.0.1/16 and + 171.69.150.226/24. The router will sweep the service registry table + looking for rows that have atmfSrvcRegParm1 values as shown below: + + Network number/mask atmfSrvcRegParm1 + -------------------- -------------------------------------- + 1.0.0.0/8 08 00 04 01 00 00 00 ff 00 00 00 + 128.10.0.0/16 08 00 04 80 0a 00 00 ff ff 00 00 + 171.69.150.0/24 08 00 04 ab 45 96 00 ff ff ff 00 + + When the correct atmfSrvcRegParm1 values are located, the router may + then establish an SVC to the selected server and perform the + appropriate protocol operations. + + Redundant ATMARP servers are supported with multiple rows in the + service registry table. This list of ATMARP servers is ordered with + the primary ATMARP server having the lowest index value. The ATMARP + client must attempt to utilize the primary ATMARP server before + utilizing a secondary ATMARP server. Administrators must ensure that + the listed ATMARP servers are synchronized. + +5. ATMARP Server Behavior + + An ATMARP server shall be locally configured. The ATMARP server may + retrieve the ATMARP service registry data to validate the results. If + an incorrect row is retrieved the error may be flagged in a locally + significant way. + +6. Relationship with PNNI Augmented Routing + + An augmented version PNNI ("PNNI Augmented Routing," or PAR) [3] has + been developed by the ATM Forum. PAR can distribute data such as + ATMARP server addresses. Further, the ATM Forum is developing a proxy + mechanism for PAR (Proxy PAR) that would allow a UNI-attached host or + router to access PAR data without a full PAR implementation. These + mechanisms offer a promising way to manage the service registry + tables maintained on each switch in an ATM network, yet would not + require changes to the mechanism defined in this memo. Hosts and + routers can continue to utilize ILMI-based or Proxy PAR-based server + discovery and network administrators could manage the service + registry data with local configuration or via PAR and Proxy PAR. + + + + + + + + + + +Davison Standards Track [Page 4] + +RFC 2601 ILMI-Based Server Discovery for ATMARP June 1999 + + +7. Security Considerations + + The server discovery mechanism is built on the ILMI managment + framework and the security embodied in that framework. Access, to + user- or network-side information is controlled by MIB design rather + than protocol security mechanisms. + + The service registery MIB, the table containing information for + server discovery, is defined in [2] with read-only access. This means + that any user-side device may query the service registry, but may not + modify the service registry via ILMI. Instead, the sevice registry + table must be modified via local configuration on the ATM switch. + +References + + [1] Laubach, M. and J. Halpern, "Classical IP and ARP over ATM," RFC + 2225, April 1998. + + [2] ATM Forum, "Integrated Local Management Interface (ILMI) + Specification Version 4.0," af-ilmi-0065.000, September 1996. + + [3] ATM Forum, "PNNI Augmented Routing (PAR) Version 1.0," af-ra- + 0104, January 1999. + +Author's Address + + Mike Davison + Cisco Systems + 170 West Tasman Drive + San Jose, California 95134 + + Phone: (408) 526-4000 + EMail: mike.davison@cisco.com + + + + + + + + + + + + + + + + + + +Davison Standards Track [Page 5] + +RFC 2601 ILMI-Based Server Discovery for ATMARP June 1999 + + +Full Copyright Statement + + Copyright (C) The Internet Society (1999). All Rights Reserved. + + This document and translations of it may be copied and furnished to + others, and derivative works that comment on or otherwise explain it + or assist in its implementation may be prepared, copied, published + and distributed, in whole or in part, without restriction of any + kind, provided that the above copyright notice and this paragraph are + included on all such copies and derivative works. However, this + document itself may not be modified in any way, such as by removing + the copyright notice or references to the Internet Society or other + Internet organizations, except as needed for the purpose of + developing Internet standards in which case the procedures for + copyrights defined in the Internet Standards process must be + followed, or as required to translate it into languages other than + English. + + The limited permissions granted above are perpetual and will not be + revoked by the Internet Society or its successors or assigns. + + This document and the information contained herein is provided on an + "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING + TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING + BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION + HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF + MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + +Acknowledgement + + Funding for the RFC Editor function is currently provided by the + Internet Society. + + + + + + + + + + + + + + + + + + + +Davison Standards Track [Page 6] + |