IPS Working Group                                         David Peterson
INTERNET-DRAFT                                             Cisco Systems
<draft-ietf-ips-fcip-slp-04.txt>                          September 2002
Expires: March 2003
Category: standards-track


                   Finding FCIP Entities Using SLPv2



Status of this Memo

   This document is an Internet-Draft and is in  full  conformance  with
   all provisions of Section 10 of RFC2026.

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Copyright Notice

   Copyright (C) The Internet Society (2002). All Rights Reserved.

Abstract

   The FCIP protocol [FCIP] provides a method for the tunneling of Fibre
   Channel frames over an IP network. This document defines the  use  of
   Service  Location  Protocol,  version  2  (SLPv2)  [RFC2608], by FCIP
   Entities to  discover  one  another,  and  provides  the  appropriate
   templates describing their services.








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1.  Acknowledgements

   This  draft  was  produced by the FCIP discovery team, including Todd
   Sperry (Adaptec), Larry Lamars (SanValley), Robert Snively (Brocade),
   Ravi  Natarajan  (Lightsand),  Anil Rijhsinghani (McData), and Venkat
   Rangan (Rhapsody Networks). Thanks also to  Mark  Bakke  (Cisco)  for
   initial help and consultation.


2.  Notation Conventions

   The  key  words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in  this
   document are to be interpreted as described in [RFC2119].


3.  Terminology

   Here  are  some  definitions that may aid readers that are unfamiliar
   with either SLP, or  FCIP.   Some  of  these  definitions  have  been
   reproduced  from  [RFC2608]  and  "Finding  an  RSIP Server with SLP"
   [RSIP].

   User Agent (UA)            A process working on the  client's  behalf
                              to  establish  contact  with some service.
                              The UA retrieves service information  from
                              the Service Agents or Directory Agents.

   Service Agent (SA)         A process working on behalf of one or more
                              services to  advertise  the  services  and
                              their capabilites.

   Directory Agent (DA)       A    process    which   collects   service
                              advertisements.  There can only be one  DA
                              present per given host.

   Scope                      A  named set of services, typically making
                              up a logical administrative group.

   Service Advertisement      A  URL,   attributes,   and   a   lifetime
                              (indicating  how long the advertisement is
                              valid),    providing    service     access
                              information  and  capabilities description
                              for a particular service.

   FCIP Entity                The principle FCIP interface point to  the
                              IP network.




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   FCIP Entity Name           The  world  wide name of the switch if the
                              FCIP Entity resides in  a  switch  or  the
                              world  wide  node  name  of the associated
                              Nx_Port.

   FCIP Discovery Domain      The FCIP Discovery Domain specifies  which
                              FCIP Entities are allowed to discover each
                              other within the bounds of the scope.


4.  Using SLPv2 for FCIP Service Discovery

   At least two FCIP Entities must be involved in the  entity  discovery
   process.   The end result is that an FCIP Entity will discover one or
   more peer FCIP Entities.


4.1.  Discovering FCIP Entities using SLPv2

   The following diagram shows the relationship  between  FCIP  Entities
   and their associated SLPv2 agents.

              +--------------------------------------+
              |           FCIP Entity                |
              +----------------------------------+   |
              | FCIP Control and Services Module |   |
              +----------------+                 |   |
              |   SA  |   UA   |                 |   |
              +----------------+-----------------+   |
              |            TCP/UDP/IP            |   |
              +----------------+-----------------+   |
              |            Interface             |   |
              |           180.10.1.10            |   |
              +----------------+-----------------+---|
                               |
     +------------+            |
     |  SLPv2 DA  |----+  IP Network
     +------------+            |
                               |
              +----------------+-----------------+---|
              |            Interface             |   |
              |           190.10.1.20            |   |
              +----------------+-----------------+   |
              |            TCP/UDP/IP            |   |
              +----------------+-----------------+   |
              |   SA  |  UA    |                 |   |
              +----------------+                 |   |
              | FCIP Control and Services Module |   |



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              +--------------------------------- +   |
              |           FCIP Entity                |
              +--------------------------------------+

   Fig. 1 FCIP Entity and SLPv2 Agent Relationship.

   As  indicated in the drawing above, each FCIP Entity contains an FCIP
   Control and Services Module that interfaces to an SLPv2 SA and UA.

   The   SA   constructs   a   service   advertisement   of   the   type
   "service:fcip:entity"  for  each  of  the  service  URLs it wishes to
   register. The service advertisement contains a lifetime,  along  with
   other attributes defined in the service template.

   The  remainder  of the discovery process is identical to that used by
   any client/server pair implementing SLPv2:

   1. If an SLPv2 DA is found [RFC2608], the  SA  contacts  the  DA  and
   registers  the  service advertisement.  If SLPv2 DA is not found, the
   SA maintains the service advertisement itself, and answers  multicast
   UA queries directly.

   2.  When the FCIP Entity requires contact information for a peer FCIP
   Entity, the UA either contacts the DA using unicast or the  SA  using
   multicast  using  an  SLPv2  service request.  The UA service request
   includes  a  query,  based  on  the  attributes,  to   indicate   the
   characteristics of the peer FCIP Entities it requires.

   3.  Once  the  UA  has  the IP address and port number of a peer FCIP
   Entity, it may begin the normal connection procedure, as described in
   [FCIP], to a peer FCIP Entity.

   The  use  of  a  DA  is  RECOMMENDED  for  SLPv2 operation in an FCIP
   environment.


4.1.1.  FCIP Discovery Domains

   The concept of a discovery domain  provides  further  granularity  of
   control  of allowed discovery between FCIP Entities within a specific
   SLPv2 scope.

   The following example diagram shows  the  relationship  between  FCIP
   Entities  and  their  associated discovery domains within a specified
   SLPv2 scope.






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   =================fcip======================================================
   =                                                                         =
   =  *************************purple**************************************  =
   =  *                                                                   *  =
   =  *  #####orange################################                      *  =
   =  *  # -----------------  /////////////////////+//blue//////////////  *  =
   =  *  # | FCIP Entity A |  /                    #                   /  *  =
   =  *  # -----------------  /                    # ----------------- /  *  =
   =  *  #                    /                    # | FCIP Entity C | /  *  =
   =  *  #                    /  ----------------- # ----------------- /  *  =
   =  *  #                    /  | FCIP Entity B | #                   /  *  =
   =  *  #                    /  ----------------- #                   /  *  =
   =  *  #####################+#####################                   /  *  =
   =  *                       //////////////////////////////////////////  *  =
   =  *                                                                   *  =
   =  *********************************************************************  =
   =                                                                         =
   ===========================================================================

   Fig. 2 FCIP Entity and Discovery Domain Example.

   Within the specified scope "fcip", the administrator  has  defined  a
   discovery  domain  "purple",  allowing  FCIP  Entities A, B, and C to
   discover each other.  This discovery domain is illustrated using  the
   "*" character.

   Within  the  specified  scope "fcip", the administrator has defined a
   discovery domain "orange", allowing FCIP Entity A  to  discover  FCIP
   Entity   B,  but  not  FCIP  Entity  C.   This  discovery  domain  is
   illustrated using the "#" character.

   Within the specified scope "fcip", the administrator  has  defined  a
   discovery  domain  "blue",  allowing  FCIP  Entity C to discover FCIP
   Entity  B,  but  not  FCIP  Entity  A.   This  discovery  domain   is
   illustrated using the "/" character.


4.2.  NAT and NAPT Considerations

   Since  SLPv2  provides IP address and TCP port information within its
   payload, the addresses an SA or DA advertise may not be the  same  as
   those   a  UA  must  use  if  a  Network  Address(/Port)  Translation
   (NAT/NAPT) device is present between the UA and  the  SA.   This  may
   result  in  the  UA discovering address information that is unusable.
   Below are a few recommendations to handle this:






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   - A fully-qualified domain name (i.e., not an IP address)  should  be
     used in service URLs and mgmt-entity attribute.

   - Use the default IANA-assigned FCIP TCP port number in service URLs,
     when possible.

   - If advertising service URLs through  a  NAT/NAPT  device,  and  the
     FQDN,  IP  address,  or  TCP  port will be translated, the NAT/NAPT
     device can provide an SLPv2 proxy capability to do the translation.


5.  FCIP SLPv2 Templates

   Two  templates are provided: an FCIP Entity template, and an abstract
   template to provide a means to add other FCIP  related  templates  in
   the future.


5.1.  The FCIP Abstract Service Type Template

   This template defines the abstract service "service:fcip". It is used
   as  a  top-level  service  to  encapsulate  all  other  FCIP  related
   services.

   Name of submitter: David Peterson
   Language of service template: en
   Security Considerations:
     See the security considerations of the concrete service type.

   Template Text:
   -------------------------template begins here-----------------------
   template-type=fcip

   template-version=0.1

   template-description=
     This is an abstract service type. The purpose of the fcip service type
     is to encompass all of the services used to support the FCIP protocol.

   template-url-syntax =
     url-path=  ; Depends on the concrete service type.

   --------------------------template ends here------------------------








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5.2.  The FCIP Entity Concrete Service Type Template

   This  template  defines  the  service "service:fcip:entity". A device
   containing FCIP Entities that wishes  to  have  them  discovered  via
   SLPv2  would  register each of them, with each of their addresses, as
   this service type.

   FCIP Entities wishing to discover other FCIP Entities in this  manner
   will generally use one of the following example query strings:

   1. Find a specific FCIP Entity, given its FCIP Entity Name:

      Service:    service:fcip:entity
      Scope:      fcip-entity-scope-list
      Query:      (fcip-entity-name=10:00:00:60:69:20:34:0C)

   2.  Find  all  of the FCIP Entities within a specified FCIP Discovery
   Domain:

      Service:    service:fcip:entity
      Scope:      fcip-entity-scope-list
      Query:      (fcip-discovery-domain=fcip-discovery-domain-name)

   3. In addition, a management application may  wish  to  discover  all
   FCIP Entities:

      Service:    service:fcip:entity
      Scope:      management-service-scope-list
      Query:      none


   Name of submitter: David Peterson
   Language of service template: en
   Security Considerations:
     See later section.

   Template Text:
   -------------------------template begins here-----------------------
   template-type=fcip:entity

   template-version=0.1

   template-description=
     This is a concrete service type. The fcip:entity service type is used
     to register individual FCIP Entity addresses to be discovered by others.
     UAs will generally search for these by including one of the following:
     - the FCIP Entity Name for which an address is needed
     - the FCIP Discovery Domain Name for which addresses are requested



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     - the service URL

   template-url-syntax =
     url-path          =    ipaddr [ : tcpport ] / fcip-entity-name
     ipaddr            =    DNS host name or ip address
     tcpport           =    decimal tcp port number
     fcip-entity-name  =    FCIP Entity Name
     ; The fcip-entity-name portion of the URL is required and must be the
     ; FCIP Entity Name of the entity being registered.
     ; An entity representing multiple endpoints must register each of them
     ; using SLPv2.
     ;
     ; Examples:
     ; service:fcip:entity://hammer.cisco.com:4000/10:00:00:60:69:20:34:0C
     ; service:fcip:entity://192.1.3.40:4000/10:00:00:60:69:20:34:0C
     ;
     ; A DNS host name should be used along with the well-known IANA FCIP
     ; port number for allow for operation with NAT/NAPT devices.

   fcip-entity-name = opaque
   # This must match the fcip-entity-name specified in the url-path.
   # If the FCIP Entity is a VE_Port/B_Access implementation [FC-BB-2]
   # residing in a switch, the fcip-entity-name is the Fibre Channel
   # Switch Name [FC-SW-2]. Otherwise, the fcip-entity-name is the
   # Fibre Channel Node Name [FC-FS] of the port (e.g., an Nx_Port)
   # associated with the FCIP Entity.

   transports = string M L
   tcp
   # This is a list of transport protocols that the registered entity
   # supports. FCIP is currently supported over TCP only.
   tcp

   mgmt-entity = string M O
   # The URL's of the management interface(s) appropriate for SNMP,
   # web-based, or telnet management of the FCIP Entity.
   # Examples:
   #  snmp://10.1.1.1
   #  http://fcipentity.dap.com:1080/
   #  telnet://fcipentity.dap.com

   fcip-discovery-domain = string M
   fcip
   # The fcip-discovery-domain string contains the name(s) of the FCIP
   # discovery domain(s) to which this FCIP Entity belongs.


   --------------------------template ends here------------------------



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6.  Security Considerations

   Service  type templates provide information that is used to interpret
   information obtained by clients through SLPv2. If the FCIP  templates
   are modified or if false templates are distributed, FCIP Entities may
   not correctly register themselves or may not  be  able  to  interpret
   service information.

   The  SLPv2  security model does not provide confidentiality, but does
   provide an authentication mechanism for UAs to  assure  that  service
   advertisements only come from trusted SAs [RFC2608].

   Once  an  FCIP Entity is discovered, authentication and authorization
   are handled by the FCIP protocol. It is  the  responsibility  of  the
   providers  of  these  services  to  ensure  that  an  inappropriately
   advertised or discovered service, does not comprimise their security.


6.1.  Security Implementation

   For  all  implementations, IPsec SHOULD be implemented. When security
   policy information distribution using SLPv2 is supported, IPsec  MUST
   be implemented.

   To  provide  confidentiality, IPsec with ESP and a non-null transform
   SHOULD be implemented. When security policy information  distribution
   via  SLPv2  is  used, IPsec with ESP and a non-null transform MUST be
   used.

   SLPv2 authentication is OPTIONAL to  implement  and  use,  and  SLPv2
   authentication SHOULD be implemented when IPsec is not supported.

   The  use  of  IPsec and IKE for SLPv2 in an IP storage environment is
   described in [IPS-SEC].


7.  Summary

   This document describes how SLPv2 can be used  by  FCIP  Entities  to
   find  other  FCIP  Entities. Service type templates for FCIP Entities
   are presented.


8.  Normative References

The  references  in  this  section  were  current  at  the   time   this
specification  was  approved.  This specification is intended to operate
with newer versions of  the  referenced  documents.  Looking  for  newer



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references is recommended.

[RFC2608]   E.  Guttman,  C.  Perkins,  J.  Veizades,  M.  Day. "Service
            Location Protocol, version 2",  RFC 2608, July 1999.

[RFC2119]   S.  Bradner.  "Key  Words  for  Use  in  RFCs  to   Indicate
            Requirement Levels",  RFC 2119, March 1997.

[FCIP]      Rajagopal,      et.      al.     "FCIP",     draft-ietf-ips-
            fcovertcpip-12.txt, June 2002.

[RSIP]      Kempf, J., Montenegro, G. "Finding an RSIP Server with SLP",
            draft-ietf-nat-rsip-slp-00, February 2000.

[FC-SW-2]   Fibre  Channel  Switch Fabric - 2, ANSI INCITS.355:200x, May
            23, 2001.

[FC-BB-2]   Fibre Channel Backbone - 2, T11  Project  1238-D,  Rev  5.6,
            July 10, 2002.

[FC-FS]     Fibre Channel Framing and Signaling, T11 Project 1331-D, Rev
            1.70, February 8, 2002.

[IPS-SEC]   B. Aboba, et. al. "Securing  Block  Storage  Protocols  over
            IP", draft-ietf-ips-security-16.txt, September 17, 2002.


9.  Informative References

The references in this section may further assist the reader.

[RFC2609]   E.  Guttman,  C.  Perkins,  J. Kempf. "Service Templates and
            service: Schemes",  RFC 2609, July 1999.

[RFC2614]   J. Kempf, E. Guttman. "An API  for  Service  Location",  RFC
            2614, June 1999.

[2614BIS]   J.  Kempf, E. Guttman. "An API for Service Location", draft-
            kempf-srvloc-rfc2614bis-00.txt, February 2001.

[RFC3082]   J. Kempf, J Goldschmidt. "Notification and Subscription  for
            SLP", RFC 3082, March 2001.

[FCIP-MIB]  Rijhsinghani,   et.  al.  "FCIP  MIB",  draft-ietf-ips-fcip-
            mib-01.txt, January 2002.






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Author's  Address:

       David Peterson
       Cisco Systems, Inc.
       6450 Wedgwood Road
       Maple Grove, MN
       USA 55311

       Voice:  +1 763-398-1007
       E-Mail: dap@cisco.com

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   Funding for the RFC Editor function  is  currently  provided  by  the
   Internet Society.








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