Internet Draft Expires July 2002 Rob Grant McDATA Todd Sperry Adaptec Jan. 21, 2002 iSCSI EUI64-based Node Naming draft-grant-iscsi-eui64node-00.txt Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026 [1]. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or made obsolete by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Abstract This document proposes a new method of identifying iSCSI Nodes beyond the iSCSI name. The new method uses a 64-bit field to be compatible with technologies using 64-bit identifiers such as EUI-64. These technologies include Fibre Channel and Infiniband, but may also extend to storage features such as failover, LUN-level masking or storage asset management. The preferred method for distribution of this new 64-bit identifier is through registration with iSNS. An alternative method is also proposed whereby an optional Operational Key is added to the Text field of an iSCSI Login PDU. draft-grant-iscsi-eui64node-00.txt Page [2] ____________ /\/\/\/\/\/\ _____ /\/\/\/\/\/\ ____________ | portal1|===/ \==| GW1 |==/ \===|port1 | | iSCSI | \ IP / ----- \ FC / | FC | | Node | / Network \ _____ / Fabric \ | Node | | portal2|===/ \==| GW2 |==/ \===|port2 | ---------- \/\/\/\/\/\/ ----- \/\/\/\/\/\/ ------------ Figure 1: an FC to iSCSI Gateway Problem Statement: As an example of where a 64-bit node-level identifier could be used, Figure 1 shows a network topology with two gateway (or bridge) devices between an iSCSI network and a Fibre Channel fabric. Also shown is a single iSCSI Node with 2 portals and a single FC node with 2 ports. In order for a gateway to login to a FC device (FLOGI, PLOGI), the gateway must provide a FC World Wide Node Name (WWNN) and a World Wide Port Name (WWPN) - both of which are 64-bit identifiers. While it is possible for a gateway to generate such World Wide Names as needed, using various techniques, arbitrary assignments of WWNN by different gateways to represent iSCSI devices is not desirable. The WWPN, however, can be assigned by the gateway device, as it corresponds to the actual physical port being used. While this example is particular to Fibre Channel to iSCSI Gateways, the use of 64-bit identifiers is not unique to Fibre Channel. Other technologies also use the EUI-64 format as identifiers (for example, Infiniband uses a EUI-64 format Globally Unique Identifier or GUID). Further, other storage functions (automatic failover, some types of access control, asset management) have built on this use of 64-bit identification of nodes independent of the transport. The example of an iSCSI-to-FC Gateway, however, will be used to discuss various alternatives to achieving a 64-bit identifier. Why Involve the iSCSI End Node? A simple approach would be to have the gateway provide an identifier. This approach, however, could result in different gateways using a different WWNN to represent the same iSCSI node (GW1 and GW2 in the Figure). If this occurs, storage functions built on 64-bit node identification would have no way of identifying that the 2 Gateways are representing the same node. A more sophisticated implementation may attempt to have a particular gateway use a Fabric Service (on either the IP or FC fabric) to get some consistency of naming between gateways. These implementations, however, may suffer from inconsistency across Gateways (particularly between vendors). As well, they may suffer from inconsistency in naming during error or failure conditions (such as the failure of a Gateway or fabric service). While these issues may be addressed, the resolutions involve a great deal of complexity. Finally, they may still ultimately fail to identify that multiple ports in reality represent a single node. draft-grant-iscsi-eui64node-00.txt Page [3] A simple place to create consistent node-level identification is in the actual nodes. Further, having an iSCSI node "own" its 64-bit identity is consistent with other iSCSI naming. How a Node Constructs a EUI64NN A simple method would be to have an iSCSI HBA create an EUI-64 identifier using its Ethernet MAC address (EUI-64 identifers can be made from EUI-48 or MAC-48 identifiers). This allows simple implementations to use entities which already exist (the MAC address) while allowing more sophisticated implementations (that can be aware of multiple NICs) to use some other method to form a consistent node-level identification. Communicating an EUI-64 Node Name Using iSNS The preferred method for an iSCSI End Node to communicate an EUI64 Node Name is to register it with an iSNS Server. For this, the definition of the "iFCP FC Device Node Name (WWNN)" attribute of [iSNSID] would be expanded to include iSCSI nodes and renamed the "EUI-64 Node Name (EUI64NN)". This attribute would become a required attribute for iSCSI Storage Nodes supporting iSNS. The methods for iSNS attributes as defined in [iSNSID] are then used by end devices, gateways or other entities to register and query for EUI64NNs. Communicating an EUI-64 Node Name During iSCSI Login As an alternative for iSCSI storage nodes that do not support iSNS, this paper proposes a new optional Operational Key to be added to the Text field of an iSCSI Login PDU. This approach may be appropriate for nodes which are statically configured or use other discovery mechanisms such as SLP. The new Operational Key, termed the EUI64NN, would represent the EUI-64 Node Name. An example of an an EUI64NN Operational Key built from a 48-bit IEEE Standard 802.1A Universal LAN MAC address "0x123456789abc" would be EUI64NN=0x1000123456789abc. Example of EUI64NN Communication During an iSCSI Login The following shows an example of negotiation of the EUI64NN Operational Key during login. I-> Login (..., T=1) InitiatorName=iqn.1999-07.com.os.hostid.77 TargetName=iqn.1999-07.com.acme.diskarray.sn.88 EUI64NN=0x1000123456789abc T-> Login (..., T=0) EUI64NN=0x1000123456789def, 0x1000123456789ghi, 0x1000123456789jkl I-> Login (..., T=1) EUI64NN=0x1000123456789abc T-> Login (..., T=1) EUI64NN=0x1000123456789abc draft-grant-iscsi-eui64node-00.txt Page [4] Acknowledgements The authors would like to thank Anil Rijhsinghani, Ernest Dainow, Henry Yang and David Wu for their help in preparing this Internet Draft. Authors' Addresses: Rob Grant McDATA Corp. 111 Gordon Baker Rd. North York, Ontario Tel: (416) 496-6564 robert.grant@mcdata.com Todd Sperry Adaptec, Inc. 691 South Milpitas Boulevard Milpitas, Ca. 95035 Phone: (408) 957-4980 Email: todd_sperry@adaptec.com Full Copyright Statement Copyright (C) The Internet Society (2000). 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. Expires July 2002