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Internet Draft                                            David Peterson
<draft-ietf-ips-fcip-slp-03.txt>                                   Cisco
Expires February 2003
                                                             August 2002

                   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.

   Internet-Drafts are working documents  of  the  Internet  Engineering
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Copyright Notice

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


   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.

1.  Acknowledgements

   This draft was produced by the FCIP discovery  team,  including  Todd
   Sperry (Adaptec), Larry Lamars (SanValley), Robert Snively (Brocade),

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   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",
   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"

   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.

   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

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   FCIP Discovery Domain      The  FCIP Discovery Domain specifies which
                              FCIP  Entities  are  allowed  to   connect
                              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             |   |
              |             |   |
     +------------+            |
     |  SLPv2 DA  |----+  IP Network
     +------------+            |
              |            Interface             |   |
              |             |   |
              +----------------+-----------------+   |
              |            TCP/UDP/IP            |   |
              +----------------+-----------------+   |
              |   SA  |  UA    |                 |   |
              +----------------+                 |   |
              | FCIP Control and Services Module |   |
              +--------------------------------- +   |
              |           FCIP Entity                |

   Fig. 1 FCIP Entity and SLPv2 Agent Relationship.

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

   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, the SA contacts the DA and registers  the
   service  advertisement.  If  no  DA  is  found,  the SA maintains the
   service  advertisement  itself,  and  answers  multicast  UA  queries

   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

4.1.1.  FCIP Discovery Domains

   The concept of a discovery domain  provides  further  granularity  of
   control  of  the  allowed  connections 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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    =                                                                     =
    =  *************************purple**********************************  =
    =  *                                                               *  =
    =  *    #####orange#########################                       *  =
    =  *    # ------------    /////////////////+//////blue///////////  *  =
    =  *    # | FC SAN A |    /                #                    /  *  =
    =  *    # ------------    /                #      ------------  /  *  =
    =  *    #                 /                #      | FC SAN C |  /  *  =
    =  *    #                 /  ------------  #      ------------  /  *  =
    =  *    #                 /  | FC SAN B |  #                    /  *  =
    =  *    #                 /  ------------  #                    /  *  =
    =  *    ##################+#################                    /  *  =
    =  *                      ///////////////////////////////////////  *  =
    =  *                                                               *  =
    =  *****************************************************************  =
    =                                                                     =

   Fig. 2 FCIP Entity and Discovery Domain Example.

   Within the specified scope "fcip", the administrator  has  defined  a
   discovery  domain  "purple",  encompassing FC SAN's A, B, and C. This
   discovery domain is illustrated using the "*" character.

   Within the specified scope "fcip", it is determined that FC SAN A  is
   allowed  to  connect  to FC SAN B but not to FC SAN C. This discovery
   domain, labeled "orange", is illustrated using the "#" character.

   Within the specified scope "fcip", it is determined that FC SAN C  is
   allowed  to  connect  to FC SAN B but not to FC SAN A. This discovery
   domain, labeled "blue", 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:

   - Use  a fully-qualified domain name instead of IP address in service
     URLs and in the mgmt-entity attribute.

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   - 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

   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-----------------------


     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------------------------

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.

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   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

      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-----------------------


     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
     - 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

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     ; 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://
     ; 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.
   # The fcip-entity-name is either the Fibre Channel Switch Name [FC-SW-2] if the
   # FCIP Entity is embedded in a switch or the Fibre Channel Node Name [FC-FS] if
   # the FCIP Entity is not embedded in a switch (e.g., an Nx_Port).

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

   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://
   #  http://fcipentity.dap.com:1080/
   #  telnet://fcipentity.dap.com

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

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

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.

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   SLPv2 provides an authentication mechanism for  UAs  to  assure  that
   service advertisements only come from trusted SAs [RFC2608]. If trust
   is an issue, then SLPv2  authentication  should  be  enabled  in  the

   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.  IPsec Integration

   Although  SLPv2 security provides authentication, it does not provide
   confidentiality. When confidentiality is  a  concern,  in  particular
   when  SLPv2  is used to distribute security policy information, IPsec
   MUST  be  used  with  SLPv2  when  discovering  FCIP  entities.  When
   confidentiality  is  not a concern, SLPv2 security MAY be implemented
   and used.

   The use of IPsec and IKE for use with SLPv2  is  described  in  [IPS-
   SEC], and is a work in progress.

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.  References

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

[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.

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

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

[FCIP]      Rajagopal,      et.      al.     "FCIP",     draft-ietf-ips-
            fcovertcpip-11.txt, June 2002.

[FCIP-MIB]  Rijhsinghani,  et.  al.  "FCIP  MIB",   draft-ietf-ips-fcip-
            mib-01.txt, January 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-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-14.txt, July 24, 2002.

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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   followed, or as required to translate it into  languages  other  than

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   The  limited  permissions granted above are perpetual and will not be
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   This document and the information contained herein is provided on  an


   Funding  for  the  RFC  Editor  function is currently provided by the
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