tech-invite   World Map     

IETF     RFCs     Groups     SIP     ABNFs    |    3GPP     Specs     Glossaries     Architecture     IMS     UICC    |    search

RFC 4171

 
 
 

Internet Storage Name Service (iSNS)

Part 4 of 5, p. 73 to 103
Prev RFC Part       Next RFC Part

 


prevText      Top      Up      ToC       Page 73 
6.  iSNS Attributes

   Attributes can be stored in the iSNS server using iSNSP registration
   messages, and they can be retrieved using iSNSP query messages.
   Unless otherwise indicated, these attributes are supplied by iSNS
   clients using iSNSP registration messages.

6.1.  iSNS Attribute Summary

   The complete registry of iSNS attributes is maintained by IANA, and
   the following table summarizes the initial set of iSNS attributes
   available at the time of publication of this document.

   Attributes               Length   Tag   Reg Key   Query Key
   ----------               ------   ---   -------   ---------
   Delimiter                 0        0      N/A        N/A
   Entity Identifier (EID) 4-256      1       1     1|2|16&17|32|64
   Entity Protocol           4        2       1     1|2|16&17|32|64
   Management IP Address     16       3       1     1|2|16&17|32|64
   Timestamp                 8        4      --     1|2|16&17|32|64
   Protocol Version Range    4        5       1     1|2|16&17|32|64
   Registration Period       4        6       1     1|2|16&17|32|64
   Entity Index              4        7       1     1|2|16&17|32|64
   Entity Next Index         4        8      --     1|2|16&17|32|64
   Entity ISAKMP Phase-1    var       11      1     1|2|16&17|32|64
   Entity Certificate       var       12      1     1|2|16&17|32|64
   Portal IP Address         16       16      1     1|16&17|32|64
   Portal TCP/UDP Port       4        17      1     1|16&17|32|64
   Portal Symbolic Name    4-256      18    16&17   1|16&17|32|64
   ESI Interval              4        19    16&17   1|16&17|32|64
   ESI Port                  4        20    16&17   1|16&17|32|64
   Portal Index              4        22    16&17   1|16&17|32|64
   SCN Port                  4        23    16&17   1|16&17|32|64
   Portal Next Index         4        24     --     1|16&17|32|64
   Portal Security Bitmap    4        27    16&17   1|16&17|32|64
   Portal ISAKMP Phase-1    var       28    16&17   1|16&17|32|64
   Portal ISAKMP Phase-2    var       29    16&17   1|16&17|32|64
   Portal Certificate       var       31    16&17   1|16&17|32|64
   iSCSI Name              4-224      32      1     1|16&17|32|33
   iSCSI Node Type           4        33     32     1|16&17|32
   iSCSI Alias             4-256      34     32     1|16&17|32
   iSCSI SCN Bitmap          4        35     32     1|16&17|32
   iSCSI Node Index          4        36     32     1|16&17|32
   WWNN Token                8        37     32     1|16&17|32

Top      Up      ToC       Page 74 
   iSCSI Node Next Index     4        38     --     1|16&17|32
   iSCSI AuthMethod         var       42     32     1|16&17|32
   PG iSCSI Name           4-224      48   32|16&17 1|16&17|32|52
   PG Portal IP Addr        16        49   32|16&17 1|16&17|32|52
   PG Portal TCP/UDP Port    4        50   32|16&17 1|16&17|32|52
   PG Tag (PGT)              4        51   32|16&17 1|16&17|32|52
   PG Index                  4        52   32|16&17 1|16&17|32|52
   PG Next Index             4        53     --     1|16&17|32|52
   FC Port Name WWPN         8        64     1     1|16&17|64|66|96|128
   Port ID                   4        65     64     1|16&17|64
   FC Port Type              4        66     64     1|16&17|64
   Symbolic Port Name      4-256      67     64     1|16&17|64
   Fabric Port Name          8        68     64     1|16&17|64
   Hard Address              4        69     64     1|16&17|64
   Port IP-Address          16        70     64     1|16&17|64
   Class of Service          4        71     64     1|16&17|64
   FC-4 Types               32        72     64     1|16&17|64
   FC-4 Descriptor         4-256      73     64     1|16&17|64
   FC-4 Features            128       74     64     1|16&17|64
   iFCP SCN bitmap           4        75     64     1|16&17|64
   Port Role                 4        76     64     1|16&17|64
   Permanent Port Name       8        77     --     1|16&17|64
   FC-4 Type Code            4        95     --     1|16&17|64
   FC Node Name WWNN         8        96     64     1|16&17|64|96
   Symbolic Node Name      4-256      97     96     64|96
   Node IP-Address           16       98     96     64|96
   Node IPA                  8        99     96     64|96
   Proxy iSCSI Name        4-256     101     96     64|96
   Switch Name               8       128     128    128
   Preferred ID              4       129     128    128
   Assigned ID               4       130     128    128
   Virtual_Fabric_ID       4-256     131     128    128
   iSNS Server Vendor OUI    4       256     --     SOURCE Attribute
   Vendor-Spec iSNS Srvr          257-384    --     SOURCE Attribute
   Vendor-Spec Entity             385-512     1     1|2|16&17|32|64
   Vendor-Spec Portal             513-640   16&17   1|16&17|32|64
   Vendor-Spec iSCSI Node         641-768    32     16&17|32
   Vendor-Spec FC Port Name       769-896    64     1|16&17|64
   Vendor-Spec FC Node Name       897-1024   96     64|96
   Vendor-Specific DDS           1025-1280   2049   2049
   Vendor-Specific DD            1281-1536   2065   2065
   Other Vendor-Specific         1537-2048
   DD_Set ID                 4      2049     2049   1|32|64|2049|2065
   DD_Set Sym Name         4-256    2050     2049   2049
   DD_Set Status             4      2051     2049   2049
   DD_Set_Next_ID            4      2052     --     2049
   DD_ID                     4      2065     2049   1|32|64|2049|2065
   DD_Symbolic Name        4-256    2066     2065   2065

Top      Up      ToC       Page 75 
   DD_Member iSCSI Index     4      2067     2065   2065
   DD_Member iSCSI Name    4-224    2068     2065   2065
   DD_Member FC Port Name    8      2069     2065   2065
   DD_Member Portal Index    4      2070     2065   2065
   DD_Member Portal IP Addr 16      2071     2065   2065
   DD_Member Portal TCP/UDP  4      2072     2065   2065
   DD_Features               4      2078     2065   2065
   DD_ID Next ID             4      2079     --     2065

   The following are descriptions of the columns used in the above
   table:

   Length:    indicates the attribute length in bytes used for the TLV
              format.  Variable-length identifiers are NULL-terminated
              and 4-byte aligned (NULLs are included in the length).

   Tag:       the IANA-assigned integer tag value used to identify the
              attribute.  All undefined tag values are reserved.

   Reg Key:   indicates the tag values for the object key in DevAttrReg
              messages for registering a new attribute value in the
              database.  These tags represent attributes defined as
              object keys in Section 4.

   Query Key: indicates the possible tag values for the Message Key and
              object key that are used in the DevAttrQry messages for
              retrieving a stored value from the iSNS database.

   The following is a summary of iSNS attribute tag values available for
   future allocation by IANA at the time of publication:

   Tag Values           Reg Key          Query Key
   ----------           -------          ---------
   9-10, 13-15          1                1|2|16&17|32|64
   21, 25-26, 30        16&17            1|16&17|32|64
   39-41, 44-47         32               1|16&17|32
   54-63                32|16&17         1|16&17|32|52
   78-82, 85-94         64               1|16&17|64
   102-127              96               64|96
   132-255              --               SOURCE Attribute
   2053-2064            2049             2049
   2073-2077            2065             2065
   2080-65535           To be assigned   To be assigned

   Registration and query keys for attributes with tags in the range
   2080 to 65535 are to be documented in the RFC introducing the new
   iSNS attributes.  IANA will maintain registration of these values as
   required by the new RFC.

Top      Up      ToC       Page 76 
   New iSNS attributes with any of the above tag values MAY also be
   designated as "read-only" attributes.  The new RFC introducing these
   attributes as "read-only" SHALL document them as such, and IANA will
   record their corresponding Registration Keys (Reg Keys) as "--".

6.2.  Entity Identifier-Keyed Attributes

   The following attributes are stored in the iSNS server using the
   Entity Identifier attribute as the key.

6.2.1.  Entity Identifier (EID)

   The Entity Identifier (EID) is variable-length UTF-8 encoded NULL-
   terminated text-based description for a Network Entity.  This key
   attribute uniquely identifies each Network Entity registered in the
   iSNS server.  The attribute length varies from 4 to 256 bytes
   (including the NULL termination), and is a unique value within the
   iSNS server.

   If the iSNS client does not provide an EID during registration, the
   iSNS server SHALL generate one that is unique within the iSNS
   database.  If an EID is to be generated, then the EID attribute value
   in the registration message SHALL be empty (0 length).  The generated
   EID SHALL be returned in the registration response.

   In environments where the iSNS server is integrated with a DNS
   infrastructure, the Entity Identifier may be used to store the Fully
   Qualified Domain Name (FQDN) of the iSCSI or iFCP device.  FQDNs of
   greater than 255 bytes MUST NOT be used.

   If FQDNs are not used, the iSNS server can be used to generate EIDs.
   EIDs generated by the iSNS server MUST begin with the string "isns:".
   iSNS clients MUST NOT generate and register EIDs beginning with the
   string "isns:".

   This field MUST be normalized according to the nameprep template
   [NAMEPREP] before it is stored in the iSNS database.

6.2.2.  Entity Protocol

   The Entity Protocol is a required 4-byte integer attribute that
   indicates the block storage protocol used by the registered NETWORK
   ENTITY.  Values used for this attribute are assigned and maintained
   by IANA.  The initial set of protocols supported by iSNS is as
   follows:

Top      Up      ToC       Page 77 
          Value          Entity Protocol Type
          -----          --------------------
           1             No Protocol
           2             iSCSI
           3             iFCP
           All others    To be assigned by IANA

   'No Protocol' is used to indicate that the Network Entity does not
   support an IP block storage protocol.  A Control Node or monitoring
   Node would likely (but not necessarily) use this value.

   This attribute is required during initial registration of the Network
   Entity.

6.2.3.  Management IP Address

   This field contains the IP Address that may be used to manage the
   Network Entity and all Storage Nodes contained therein via the iSNS
   MIB [iSNSMIB].  Some implementations may also use this IP address to
   support vendor-specific proprietary management protocols.  The
   Management IP Address is a 16-byte field that may contain an IPv4 or
   IPv6 address.  When this field contains an IPv4 value, it is stored
   as an IPv4-mapped IPv6 address.  That is, the most significant 10
   bytes are set to 0x00, with the next two bytes set to 0xFFFF
   [RFC2373].  When this field contains an IPv6 value, the entire 16-
   byte field is used.  If this field is not set, then in-band
   management through the IP address of one of the Portals of the
   Network Entity is assumed.

6.2.4.  Entity Registration Timestamp

   This field indicates the most recent time when the Network Entity
   registration occurred or when an associated object attribute was
   updated or queried by the iSNS client registering the Network Entity.
   The time format is, in seconds, the update period since the standard
   base time of 00:00:00 GMT on January 1, 1970.  This field cannot be
   explicitly registered.  This timestamp TLV format is also used in the
   SCN and ESI messages.

6.2.5.  Protocol Version Range

   This field contains the minimum and maximum version of the block
   storage protocol supported by the Network Entity.  The most
   significant two bytes contain the maximum version supported, and the
   least significant two bytes contain the minimum version supported.
   If a range is not registered, then the Network Entity is assumed to

Top      Up      ToC       Page 78 
   support all versions of the protocol.  The value 0xffff is a wildcard
   that indicates no minimum or maximum.  If the Network Entity does not
   support a protocol, then this field SHALL be set to 0.

6.2.6.  Registration Period

   This 4-byte unsigned integer field indicates the maximum period, in
   seconds, that the registration SHALL be maintained by the server
   without receipt of an iSNS message from the iSNS client that
   registered the Network Entity.  Entities that are not registered for
   ESI monitoring MUST have a non-zero Registration Period.  If a
   Registration Period is not requested by the iSNS client and Entity
   Status Inquiry (ESI) messages are not enabled for that client, then
   the Registration Period SHALL be set to a non-zero value by the iSNS
   server.  This implementation-specific value for the Registration
   Period SHALL be returned in the registration response to the iSNS
   client.  The Registration Period may be set to zero, indicating its
   non-use, only if ESI messages are enabled for that Network Entity.

   The registration SHALL be removed from the iSNS database if an iSNS
   Protocol message is not received from the iSNS client before the
   registration period has expired.  Receipt of any iSNS Protocol
   message from the iSNS client automatically refreshes the Entity
   Registration Period and Entity Registration Timestamp.  To prevent a
   registration from expiring, the iSNS client should send an iSNS
   Protocol message to the iSNS server at intervals shorter than the
   registration period.  Such a message can be as simple as a query for
   one of its own attributes, using its associated iSCSI Name or FC Port
   Name WWPN as the Source attribute.

   For an iSNS client that is supporting a Network Entity with multiple
   Storage Node objects, receipt of an iSNS message from any Storage
   Node of that Network Entity is sufficient to refresh the registration
   for all Storage Node objects of the Network Entity.

   If ESI support is requested as part of a Portal registration, the ESI
   Response message received from the iSNS client by the iSNS server
   SHALL refresh the registration.

6.2.7.  Entity Index

   The Entity Index is an unsigned non-zero integer value that uniquely
   identifies each Network Entity registered in the iSNS server.  Upon
   initial registration of a Network Entity, the iSNS server assigns an
   unused value for the Entity Index.  Each Network Entity in the iSNS
   database MUST be assigned a value for the Entity Index that is not

Top      Up      ToC       Page 79 
   assigned to any other Network Entity.  Furthermore, Entity Index
   values for recently deregistered Network Entities SHOULD NOT be
   reused in the short term.

   The Entity Index MAY be used to represent the Network Entity in
   situations when the Entity Identifier is too long or otherwise
   inappropriate.  An example of this is when SNMP is used for
   management, as described in Section 2.10.

6.2.8.  Entity Next Index

   This is a virtual attribute containing a 4-byte integer value that
   indicates the next available (i.e., unused) Entity Index value.  This
   attribute may only be queried; the iSNS server SHALL return an error
   code of 3 (Invalid Registration) to any client that attempts to
   register a value for this attribute.  A Message Key is not required
   when exclusively querying for this attribute.

   The Entity Next Index MAY be used by an SNMP client to create an
   entry in the iSNS server.  SNMP requirements are described in Section
   2.10.

6.2.9.  Entity ISAKMP Phase-1 Proposals

   This field contains the IKE Phase-1 proposal, listing in decreasing
   order of preference the protection suites acceptable to protect all
   IKE Phase-2 messages sent and received by the Network Entity.  This
   includes Phase-2 SAs from the iSNS client to the iSNS server as well
   as to peer iFCP and/or iSCSI devices.  This attribute contains the SA
   payload, proposal payload(s), and transform payload(s) in the ISAKMP
   format defined in [RFC2408].

   This field should be used if the implementer wishes to define a
   single phase-1 SA security configuration used to protect all phase-2
   IKE traffic.  If the implementer desires to have a different phase-1
   SA security configuration to protect each Portal interface, then the
   Portal Phase-1 Proposal (Section 6.3.10) should be used.

6.2.10.  Entity Certificate

   This attribute contains one or more X.509 certificates that are bound
   to the Network Entity.  This certificate is uploaded and registered
   to the iSNS server by clients wishing to allow other clients to
   authenticate themselves and to access the services offered by that
   Network Entity.  The format of the X.509 certificate is found in
   [RFC3280].  This certificate MUST contain a Subject Name with an
   empty sequence and MUST contain a SubjectAltName extension encoded

Top      Up      ToC       Page 80 
   with the dNSName type.  The Entity Identifier (Section 6.2.1) of the
   identified Entity MUST be stored in the SubjectAltName field of the
   certificate.

6.3.  Portal-Keyed Attributes

   The following Portal attributes are registered in the iSNS database
   using the combined Portal IP-Address and Portal TCP/UDP Port as the
   key.  Each Portal is associated with one Entity Identifier object
   key.

6.3.1.  Portal IP Address

   This attribute is the IP address of the Portal through which a
   Storage Node can transmit and receive storage data.  The Portal IP
   Address is a 16-byte field that may contain an IPv4 or IPv6 address.
   When this field contains an IPv4 address, it is stored as an IPv4-
   mapped IPv6 address.  That is, the most significant 10 bytes are set
   to 0x00, with the next 2 bytes set to 0xFFFF [RFC2373].  When this
   field contains an IPv6 address, the entire 16-byte field is used.
   The Portal IP Address and the Portal TCP/UDP Port number (see 6.3.2
   below) are used as a key to identify a Portal uniquely.  It is a
   required attribute for registration of a Portal.

6.3.2.  Portal TCP/UDP Port

   The TCP/UDP port of the Portal through which a Storage Node can
   transmit and receive storage data.  Bits 16 to 31 represents the
   TCP/UDP port number.  Bit 15 represents the port type.  If bit 15 is
   set, then the port type is UDP.  Otherwise it is TCP.  Bits 0 to 14
   are reserved.

   If the field value is 0, then the port number is the implied
   canonical port number and type of the protocol indicated by the
   associated Entity Type.

   The Portal IP Address and the Portal TCP/UDP Port number are used as
   a key to identify a Portal uniquely.  It is a required attribute for
   registration of a Portal.

6.3.3.  Portal Symbolic Name

   A variable-length UTF-8 encoded NULL-terminated text-based
   description of up to 256 bytes.  The Portal Symbolic Name is a user-
   readable description of the Portal entry in the iSNS server.

Top      Up      ToC       Page 81 
6.3.4.  Entity Status Inquiry Interval

   This field indicates the requested time, in seconds, between Entity
   Status Inquiry (ESI) messages sent from the iSNS server to this
   Network Entity.  ESI messages can be used to verify that a Portal
   registration continues to be valid.  To request monitoring by the
   iSNS server, an iSNS client registers a non-zero value for this
   Portal attribute using a DevAttrReg message.  The client MUST
   register an ESI Port on at least one of its Portals to receive the
   ESI monitoring.

   If the iSNS server does not receive an expected response to an ESI
   message, it SHALL attempt an administratively configured number of
   re-transmissions of the ESI message.  The ESI Interval period begins
   with the iSNS server's receipt of the last ESI Response.  All re-
   transmissions MUST be sent before twice the ESI Interval period has
   passed.  If no response is received from any of the ESI messages,
   then the Portal SHALL be deregistered.  Note that only Portals that
   have registered a value in their ESI Port field can be deregistered
   in this way.

   If all Portals associated with a Network Entity that have registered
   for ESI messages are deregistered due to non-response, and if no
   registrations have been received from the client for at least two ESI
   Interval periods, then the Network Entity and all associated objects
   (including Storage Nodes) SHALL be deregistered.

   If the iSNS server is unable to support ESI messages or the ESI
   Interval requested, it SHALL either reject the ESI request by
   returning an "ESI Not Available" Status Code or modify the ESI
   Interval attribute by selecting its own suitable value and returning
   that value in the Operating Attributes of the registration response
   message.

   If at any time an iSNS client that is registered for ESI messages has
   not received an ESI message to any of its Portals as expected, then
   the client MAY attempt to query the iSNS server using a DevAttrQry
   message using its Entity_ID as the key.  If the query result is the
   error "no such entry", then the client SHALL close all remaining TCP
   connections to the iSNS server and assume that it is no longer
   registered in the iSNS database.  Such a client MAY attempt re-
   registration.

Top      Up      ToC       Page 82 
6.3.5.  ESI Port

   This field contains the TCP or UDP port used for ESI monitoring by
   the iSNS server at the Portal IP Address.  Bits 16 to 31 represent
   the port number.  If bit 15 is set, then the port type is UDP.
   Otherwise, the port is TCP.  Bits 0 to 14 are reserved.

   If the iSNS client registers a valid TCP or UDP port number in this
   field, then the client SHALL allow ESI messages to be received at the
   indicated TCP or UDP port.  If a TCP port is registered and a pre-
   existing TCP connection from that TCP port to the iSNS server does
   not already exist, then the iSNS client SHALL accept new TCP
   connections from the iSNS server at the indicated TCP port.

   The iSNS server SHALL return an error if a Network Entity is
   registered for ESI monitoring and none of the Portals of that Network
   Entity has an entry for the ESI Port field.  If multiple Portals have
   a registered ESI port, then the ESI message may be delivered to any
   one of the indicated Portals.

6.3.6.  Portal Index

   The Portal Index is a 4-byte non-zero integer value that uniquely
   identifies each Portal registered in the iSNS database.  Upon initial
   registration of a Portal, the iSNS server assigns an unused value for
   the Portal Index of that Portal.  Each Portal in the iSNS database
   MUST be assigned a value for the Portal Index that is not assigned to
   any other Portal.  Furthermore, Portal Index values for recently
   deregistered Portals SHOULD NOT be reused in the short term.

   The Portal Index MAY be used to represent a registered Portal in
   situations where the Portal IP-Address and Portal TCP/UDP Port is
   unwieldy to use.  An example of this is when SNMP is used for
   management, as described in Section 2.10.

6.3.7.  SCN Port

   This field contains the TCP or UDP port used by the iSNS client to
   receive SCN messages from the iSNS server.  When a value is
   registered for this attribute, an SCN message may be received on the
   indicated port for any of the Storage Nodes supported by the Portal.
   Bits 16 to 31 contain the port number.  If bit 15 is set, then the
   port type is UDP.  Otherwise, the port type is TCP.  Bits 0 to 14 are
   reserved.

   If the iSNS client registers a valid TCP or UDP port number in this
   field, then the client SHALL allow SCN messages to be received at the
   indicated TCP or UDP port.  If a TCP port is registered and a pre-

Top      Up      ToC       Page 83 
   existing TCP connection from that TCP port to the iSNS server does
   not already exist, then the iSNS client SHALL accept new TCP
   connections from the iSNS server at the indicated TCP port.

   The iSNS server SHALL return an error if an SCN registration message
   is received and none of the Portals of the Network Entity has an
   entry for the SCN Port.  If multiple Portals have a registered SCN
   Port, then the SCN SHALL be delivered to any one of the indicated
   Portals of that Network Entity.

6.3.8.  Portal Next Index

   This is a virtual attribute containing a 4-byte integer value that
   indicates the next available (i.e., unused) Portal Index value.  This
   attribute may only be queried; the iSNS server SHALL return an error
   code of 3 (Invalid Registration) to any client that attempts to
   register a value for this attribute.  A Message Key is not required
   when exclusively querying for this attribute.

   The Portal Next Index MAY be used by an SNMP client to create an
   entry in the iSNS server.  SNMP requirements are described in Section
   2.10.

6.3.9.  Portal Security Bitmap

   This 4-byte field contains flags that indicate security attribute
   settings for the Portal.  Bit 31 (Lsb) of this field must be 1
   (enabled) for this field to contain significant information.  If Bit
   31 is enabled, this signifies that the iSNS server can be used to
   store and distribute security policies and settings for iSNS clients
   (i.e., iSCSI devices).  Bit 30 must be 1 for bits 25-29 to contain
   significant information.  All other bits are reserved for non-
   IKE/IPSec security mechanisms to be specified in the future.

   Bit Position        Flag Description
   ------------        ----------------
      25               1 = Tunnel Mode Preferred; 0 = No Preference
      26               1 = Transport Mode Preferred; 0 = No Preference
      27               1 = Perfect Forward Secrecy (PFS) Enabled;
                       0 = PFS Disabled
      28               1 = Aggressive Mode Enabled; 0 = Disabled
      29               1 = Main Mode Enabled; 0 = MM Disabled
      30               1 = IKE/IPSec Enabled; 0 = IKE/IPSec Disabled
      31 (Lsb)         1 = Bitmap VALID; 0 = INVALID
      All others       RESERVED

Top      Up      ToC       Page 84 
6.3.10.  Portal ISAKMP Phase-1 Proposals

   This field contains the IKE Phase-1 proposal listing in decreasing
   order of preference of the protection suites acceptable to protect
   all IKE Phase-2 messages sent and received by the Portal.  This
   includes Phase-2 SAs from the iSNS client to the iSNS server as well
   as to peer iFCP and/or iSCSI devices.  This attribute contains the SA
   payload, proposal payload(s), and transform payload(s) in the ISAKMP
   format defined in [RFC2408].

   This field should be used if the implementer wishes to define phase-1
   SA security configuration on a per-Portal basis, as opposed to on a
   per-Network Entity basis.  If the implementer desires to have a
   single phase-1 SA security configuration to protect all phase-2
   traffic regardless of the interface used, then the Entity Phase-1
   Proposal (Section 6.2.9) should be used.

6.3.11.  Portal ISAKMP Phase-2 Proposals

   This field contains the IKE Phase-2 proposal, in ISAKMP format
   [RFC2408], listing in decreasing order of preference the security
   proposals acceptable to protect traffic sent and received by the
   Portal.  This field is used only if bits 31, 30, and 29 of the

   Security Bitmap (see 6.3.9) are enabled.  This attribute contains the
   SA payload, proposal payload(s), and associated transform payload(s)
   in the ISAKMP format defined in [RFC2408].

6.3.12.  Portal Certificate

   This attribute contains one or more X.509 certificates that are a
   credential of the Portal.  This certificate is used to identify and
   authenticate communications to the IP address and TCP/UDP Port
   supported by the Portal.  The format of the X.509 certificate is
   specified in [RFC3280].  This certificate MUST contain a Subject Name
   with an empty sequence and MUST contain a SubjectAltName extension
   encoded with the iPAddress type.  The Portal IP Address (Section
   6.3.1) of the identified Portal SHALL be stored in the SubjectAltName
   field of the certificate.

6.4.  iSCSI Node-Keyed Attributes

   The following attributes are stored in the iSNS database using the
   iSCSI Name attribute as the key.  Each set of Node-Keyed attributes
   is associated with one Entity Identifier object key.

   Although the iSCSI Name key is associated with one Entity Identifier,
   it is unique across the entire iSNS database.

Top      Up      ToC       Page 85 
6.4.1.  iSCSI Name

   This is a variable-length UTF-8 encoded NULL-terminated text-based
   description of up to 224 bytes.  This key attribute is required for
   iSCSI Storage Nodes and is provided by the iSNS client.  The
   registered iSCSI Name MUST conform to the format described in [iSCSI]
   for iSCSI Names.  The maximum size for an iSCSI Name is 223 bytes.
   Including the NULL character and 4-byte alignment (see Section
   5.3.1), the maximum iSCSI Name field size is 224 bytes.

   If an iSCSI Name is registered without an EID key, then a Network
   Entity SHALL be created and an EID assigned.  The assigned EID SHALL
   be returned in the registration response as an operating attribute.

   This field MUST be normalized according to the stringprep template
   [STRINGPREP] before it is stored in the iSNS database.

6.4.2.  iSCSI Node Type

   This required 32-bit field is a bitmap indicating the type of iSCSI
   Storage Node.  The bit positions are defined below.  A set bit (1)
   indicates that the Node has the corresponding characteristics.

          Bit Position    Node Type
          ------------    ---------
           29             Control
           30             Initiator
           31 (Lsb)       Target
           All others     RESERVED

   If the Target bit is set to 1, then the Node represents an iSCSI
   target.  The Target bit MAY be set by iSNS clients using the iSNSP.

   If the Initiator bit is set to 1, then the Node represents an iSCSI
   initiator.  The Initiator bit MAY be set by iSNS clients using the
   iSNSP.

   If the control bit is set to 1, then the Node represents a gateway, a
   management station, a backup iSNS server, or another device that is
   not an initiator or target, but that requires the ability to send and
   receive iSNSP messages, including state change notifications.
   Setting the control bit is an administrative task that MUST be
   performed on the iSNS server; iSNS clients SHALL NOT be allowed to
   change this bit using the iSNSP.

Top      Up      ToC       Page 86 
   This field MAY be used by the iSNS server to distinguish among
   permissions by different iSCSI Node types for accessing various iSNS
   functions.  More than one Node Type bit may be simultaneously
   enabled.

6.4.3.  iSCSI Node Alias

   This is a variable-length UTF-8 encoded NULL-terminated text-based
   description of up to 256 bytes.  The Alias is a user-readable
   description of the Node entry in the iSNS database.

6.4.4.  iSCSI Node SCN Bitmap

   The iSCSI Node SCN Bitmap indicates events for which the registering
   iSNS client wishes to receive a notification message.  The following
   table displays events that result in notifications, and the bit field
   in the SCN Bitmap that, when enabled, results in the corresponding
   notification.

   Note that this field is of dual use: it is used in the SCN
   registration process to define interested events that will trigger an
   SCN message, and it is also contained in each SCN message itself, to
   indicate the type of event that triggered the SCN message.  A set bit
   (1) indicates the corresponding type of SCN.

          Bit Position       Flag Description
          ------------       ----------------
           24                INITIATOR AND SELF INFORMATION ONLY
           25                TARGET AND SELF INFORMATION ONLY
           26                MANAGEMENT REGISTRATION/SCN
           27                OBJECT REMOVED
           28                OBJECT ADDED
           29                OBJECT UPDATED
           30                DD/DDS MEMBER REMOVED (Mgmt Reg/SCN only)
           31 (Lsb)          DD/DDS MEMBER ADDED (Mgmt Reg/SCN only)
           All others        RESERVED

   DD/DDS MEMBER REMOVED indicates that an existing member of a
   Discovery Domain and/or Discovery Domain Set has been removed.

   DD/DDS MEMBER ADDED indicates that a new member was added to an
   existing DD and/or DDS.

   OBJECT REMOVED, OBJECT ADDED, and OBJECT UPDATED indicate a Network
   Entity, Portal, Storage Node, FC Device, DD, and/or DDS object was
   removed from, added to, or updated in the Discovery Domain or in the
   iSNS database (Control Nodes only).

Top      Up      ToC       Page 87 
   Regular SCNs provide information about objects that are updated in,
   added to or removed from Discovery Domains of which the Storage Node
   is a member.  An SCN or SCN registration is considered a regular SCN
   or regular SCN registration if the MANAGEMENT REGISTRATION/SCN flag
   is cleared.  All iSNS clients may register for regular SCNs.

   Management SCNs provide information about all changes to the network,
   regardless of discovery domain membership.  Registration for
   management SCNs is indicated by setting bit 26 to 1.  Only Control
   Nodes may register for management SCNs.  Bits 30 and 31 may only be
   enabled if bit 26 is set to 1.

   TARGET AND SELF INFORMATION ONLY SCNs (bit 25) provides information
   only about changes to target devices, or if the iSCSI Storage Node
   itself has undergone a change.  Similarly, INITIATOR AND SELF
   INFORMATION ONLY SCNs (bit 24) provides information only about
   changes to initiator Nodes, or to the target itself.

6.4.5.  iSCSI Node Index

   The iSCSI Node Index is a 4-byte non-zero integer value used as a key
   that uniquely identifies each iSCSI Storage Node registered in the
   iSNS database.  Upon initial registration of the iSCSI Storage Node,
   the iSNS server assigns an unused value for the iSCSI Node Index.
   Each iSCSI Node MUST be assigned a value for the iSCSI Node Index
   that is not assigned to any other iSCSI Storage Node.  Furthermore,
   iSCSI Node Index values for recently deregistered iSCSI Storage Nodes
   SHOULD NOT be reused in the short term.

   The iSCSI Node Index may be used as a key to represent a registered
   Node in situations where the iSCSI Name is too long to be used as a
   key.  An example of this is when SNMP is used for management, as
   described in Section 2.10.

   The value assigned for the iSCSI Node Index SHALL persist as long as
   the iSCSI Storage Node is registered in the iSNS database or a member
   of a Discovery Domain.  An iSCSI Node Index value that is assigned
   for a Storage Node SHALL NOT be used for any other Storage Node as
   long as the original node is registered in the iSNS database or a
   member of a Discovery Domain.

6.4.6.  WWNN Token

   This field contains a globally unique 64-bit integer value that can
   be used to represent the World Wide Node Name of the iSCSI device in
   a Fibre Channel fabric.  This identifier is used during the device
   registration process and MUST conform to the requirements in [FC-FS].

Top      Up      ToC       Page 88 
   The FC-iSCSI gateway uses the value found in this field to register
   the iSCSI device in the Fibre Channel name server.  It is stored in
   the iSNS server to prevent conflict when "proxy" WWNN values are
   assigned to iSCSI initiators establishing storage sessions to devices
   in the FC fabric.

   If the iSNS client does not assign a value for WWNN Token, then the
   iSNS server SHALL provide a value for this field upon initial
   registration of the iSCSI Storage Node.  The process by which the
   WWNN Token is assigned by the iSNS server MUST conform to the
   following requirements:

   1.  The assigned WWNN Token value MUST be unique among all WWN
       entries in the existing iSNS database, and among all devices that
       can potentially be registered in the iSNS database.

   2.  Once the value is assigned, the iSNS server MUST persistently
       save the mapping between the WWNN Token value and registered
       iSCSI Name.  That is, successive re-registrations of the iSCSI
       Storage Node keyed by the same iSCSI Name maintain the original
       mapping to the associated WWNN Token value in the iSNS server.
       Similarly, the mapping SHALL be persistent across iSNS server
       reboots.  Once assigned, the mapping can only be changed if a
       DevAttrReg message from an authorized iSNS client explicitly
       provides a different WWNN Token value.

   3.  Once a WWNN Token value has been assigned and mapped to an iSCSI
       name, that WWNN Token value SHALL NOT be reused or mapped to any
       other iSCSI name.

   4.  The assigned WWNN Token value MUST conform to the formatting
       requirements of [FC-FS] for World Wide Names (WWNs).

   An iSNS client, such as an FC-iSCSI gateway or the iSCSI initiator,
   MAY register its own WWNN Token value or overwrite the iSNS Server-
   supplied WWNN Token value, if it wishes to supply its own iSCSI-FC
   name mapping.  This is accomplished using the DevAttrReg message with
   the WWNN Token (tag=37) as an operating attribute.  Once overwritten,
   the new WWNN Token value MUST be stored and saved by the iSNS server,
   and all requirements specified above continue to apply.  If an iSNS
   client attempts to register a value for this field that is not unique
   in the iSNS database or that is otherwise invalid, then the
   registration SHALL be rejected with an Status Code of 3 (Invalid
   Registration).

Top      Up      ToC       Page 89 
   There MAY be matching records in the iSNS database for the Fibre
   Channel device specified by the WWNN Token.  These records may
   contain device attributes for that FC device registered in the Fibre
   Channel fabric name server.

6.4.7.  iSCSI Node Next Index

   This is a virtual attribute containing a 4-byte integer value that
   indicates the next available (i.e., unused) iSCSI Node Index value.
   This attribute may only be queried; the iSNS server SHALL return an
   error code of 3 (Invalid Registration) to any client that attempts to
   register a value for this attribute.  A Message Key is not required
   when exclusively querying for this attribute.

   The iSCSI Node Next Index MAY be used by an SNMP client to create an
   entry in the iSNS server.  SNMP requirements are described in Section
   2.10.

6.4.8.  iSCSI AuthMethod

   This attribute contains a NULL-terminated string of UTF-8 text
   listing the iSCSI authentication methods enabled for this iSCSI
   Storage Node, in order of preference.  The text values used to
   identify iSCSI authentication methods are embedded in this string
   attribute and delineated by a comma.  The text values are identical
   to those found in the main iSCSI document [iSCSI]; additional
   vendor-specific text values are also possible.

          Text Value       Description                   Reference
          ----------       -----------                   ---------
           KB5             Kerberos V5                   [RFC1510]
           SPKM1           Simple Public Key GSS-API     [RFC2025]
           SPKM2           Simple Public Key GSS-API     [RFC2025]
           SRP             Secure Remote Password        [RFC2945]
           CHAP            Challenge Handshake Protocol  [RFC1994]
           none            No iSCSI Authentication

6.5.  Portal Group (PG) Object-Keyed Attributes

   The following attributes are used to associate Portal and iSCSI
   Storage Node objects.  PG objects are stored in the iSNS database
   using the PG iSCSI Name, the PG Portal IP Address, and the PG Portal
   TCP/UDP Port as keys.  New PG objects are implicitly or explicitly
   created at the time that the corresponding Portal and/or iSCSI
   Storage Node objects are registered.  Section 3.4 has a general
   discussion of PG usage.  For further details on use of Portal Groups,
   see [iSCSI].

Top      Up      ToC       Page 90 
6.5.1.  Portal Group iSCSI Name

   This is the iSCSI Name for the iSCSI Storage Node that is associated
   with the PG object.  This name MAY represent an iSCSI Storage Node
   not currently registered in the server.

6.5.2.  PG Portal IP Addr

   This is the Portal IP Address attribute for the Portal that is
   associated with the PG object.  This Portal IP Address MAY be that of
   a Portal that is not currently registered in the server.

6.5.3.  PG Portal TCP/UDP Port

   This is the Portal TCP/UDP Port attribute for the Portal that is
   associated with the PG object.  This Portal TCP/UDP Port MAY be that
   of a Portal that is not currently registered in the server.

6.5.4.  Portal Group Tag (PGT)

   This field is used to group Portals in order to coordinate
   connections in a session across Portals to a specified iSCSI Node.
   The PGT is a value in the range of 0-65535, or NULL.  A NULL PGT
   value is registered by using 0 for the length in the TLV during
   registration.  The two least significant bytes of the value contain
   the PGT for the object.  The two most significant bytes are reserved.
   If a PGT value is not explicitly registered for an iSCSI Storage Node
   and Portal pair, then the PGT value SHALL be implicitly registered as
   0x00000001.

6.5.5.  Portal Group Index

   The PG Index is a 4-byte non-zero integer value used as a key that
   uniquely identifies each PG object registered in the iSNS database.
   Upon initial registration of a PG object, the iSNS server MUST assign
   an unused value for the PG Index.  Furthermore, PG Index values for
   recently deregistered PG objects SHOULD NOT be reused in the short
   term.

   The PG Index MAY be used as the key to reference a registered PG in
   situations where a unique index for each PG object is required.  It
   MAY also be used as the message key in an iSNS message to query or
   update a pre-existing PG object.  An example of this is when SNMP is
   used for management, as described in Section 2.10.  The value
   assigned for the PG Index SHALL persist as long as the server is
   active.

Top      Up      ToC       Page 91 
6.5.6.  Portal Group Next Index

   The PG Next Index is a virtual attribute containing a 4-byte integer
   value that indicates the next available (i.e., unused) PG Index
   value.  This attribute may only be queried; the iSNS server SHALL
   return an error code of 3 (Invalid Registration) to any client that
   attempts to register a value for this attribute.  A Message Key is
   not required when exclusively querying for this attribute.

   The Portal Group Next Index MAY be used by an SNMP client to create
   an entry in the iSNS server.  SNMP requirements are described in
   Section 2.10.

6.6.  FC Port Name-Keyed Attributes

   The following attributes are registered in the iSNS database using
   the FC Port World Wide Name (WWPN) attribute as the key.  Each set of
   FC Port-Keyed attributes is associated with one Entity Identifier
   object key.

   Although the FC Port World Wide Name is associated with one Entity
   Identifier, it is also globally unique.

6.6.1.  FC Port Name (WWPN)

   This 64-bit identifier uniquely defines the FC Port, and it is the
   World Wide Port Name (WWPN) of the corresponding Fibre Channel
   device.  This attribute is the key for the iFCP Storage Node.  This
   globally unique identifier is used during the device registration
   process, and it uses a value conforming to IEEE EUI-64 [EUI-64].

6.6.2.  Port ID (FC_ID)

   The Port Identifier is a Fibre Channel address identifier assigned to
   an N_Port or NL_Port during fabric login.  The format of the Port
   Identifier is defined in [FC-FS].  The least significant 3 bytes
   contain this address identifier.  The most significant byte is
   RESERVED.

Top      Up      ToC       Page 92 
6.6.3.  FC Port Type

   Indicates the type of FC port.  Encoded values for this field are
   listed in the following table:

          Type              Description
          ----              -----------
           0x0000           Unidentified/Null Entry
           0x0001           Fibre Channel N_Port
           0x0002           Fibre Channel NL_Port
           0x0003           Fibre Channel F/NL_Port
           0x0004-0080      RESERVED
           0x0081           Fibre Channel F_Port
           0x0082           Fibre Channel FL_Port
           0x0083           RESERVED
           0x0084           Fibre Channel E_Port
           0x0085-00FF      RESERVED
           0xFF11           RESERVED
           0xFF12           iFCP Port
           0xFF13-FFFF      RESERVED

6.6.4.  Symbolic Port Name

   This is a variable-length UTF-8 encoded NULL-terminated text-based
   description of up to 256 bytes that is associated with the iSNS-
   registered FC Port Name in the network.

6.6.5.  Fabric Port Name (FWWN)

   This 64-bit identifier uniquely defines the fabric port.  If the port
   of the FC Device is attached to a Fibre Channel fabric port with a
   registered Port Name, then that fabric Port Name SHALL be indicated
   in this field.

6.6.6.  Hard Address

   This field is the requested hard address 24-bit NL Port Identifier,
   included in the iSNSP for compatibility with Fibre Channel Arbitrated
   Loop devices and topologies.  The least significant 3 bytes of this
   field contain the address.  The most significant byte is RESERVED.

6.6.7.  Port IP Address

   The Fibre Channel IP address associated with the FC Port.  When this
   field contains an IPv4 value, it is stored as an IPv4-mapped IPv6
   address.  That is, the most significant 10 bytes are set to 0x00,
   with the next two bytes set to 0xFFFF [RFC2373].  When an IPv6 value
   is contained in this field, then the entire 16-byte field is used.

Top      Up      ToC       Page 93 
6.6.8.  Class of Service (COS)

   This 32-bit bit-map field indicates the Fibre Channel Class of
   Service types that are supported by the registered port.  In the
   following table, a set bit (1) indicates a Class of Service
   supported.

          Bit Position       Description
          ------------       -----------
           29                Fibre Channel Class 2 Supported
           28                Fibre Channel Class 3 Supported

6.6.9.  FC-4 Types

   This 32-byte field indicates the FC-4 protocol types supported by the
   associated port.  This field can be used to support Fibre Channel
   devices and is consistent with FC-GS-4.

6.6.10.  FC-4 Descriptor

   This is a variable-length UTF-8 encoded NULL-terminated text-based
   description of up to 256 bytes that is associated with the iSNS-
   registered device port in the network.  This field can be used to
   support Fibre Channel devices and is consistent with FC-GS-4.

6.6.11.  FC-4 Features

   This is a 128-byte array, 4 bits per type, for the FC-4 protocol
   types supported by the associated port.  This field can be used to
   support Fibre Channel devices and is consistent with FC-GS-4.

6.6.12.  iFCP SCN Bitmap

   This field indicates the events the iSNS client is interested in.
   These events can cause SCNs to be generated.  SCNs provide
   information about objects that are updated in, added to or removed
   from Discovery Domains of which the source and destination are a
   member.  Management SCNs provide information about all changes to the
   network.  A set bit (1) indicates the type of SCN for the bitmap as
   follows:

Top      Up      ToC       Page 94 
          Bit Position       Flag Description
          ------------       ----------------
           24                INITIATOR AND SELF INFORMATION ONLY
           25                TARGET AND SELF INFORMATION ONLY
           26                MANAGEMENT REGISTRATION/SCN
           27                OBJECT REMOVED
           28                OBJECT ADDED
           29                OBJECT UPDATED
           30                DD/DDS MEMBER REMOVED (Mgmt Reg/SCN only)
           31 (Lsb)          DD/DDS MEMBER ADDED (Mgmt Reg/SCN only)
           All others        RESERVED

   Further information on the use of the bit positions specified above
   can be found in Section 6.4.4.

6.6.13.  Port Role

   This required 32-bit field is a bitmap indicating the type of iFCP
   Storage Node.  The bit fields are defined below.  A set bit indicates
   the Node has the corresponding characteristics.

          Bit Position       Node Type
          ------------       ---------
           29                Control
           30                FCP Initiator
           31 (Lsb)          FCP Target
           All Others        RESERVED

   If the 'Target' bit is set to 1, then the port represents an FC
   target.  Setting of the 'Target' bit MAY be performed by iSNS clients
   using the iSNSP.

   If the 'Initiator' bit is set to 1, then the port represents an FC
   initiator.  Setting of the 'Initiator' bit MAY be performed by iSNS
   clients using the iSNSP.

   If the 'Control' bit is set to 1, then the port represents a gateway,
   a management station, an iSNS backup server, or another device.

   This is usually a special device that is neither an initiator nor a
   target, which requires the ability to send and receive iSNSP
   messages, including state-change notifications.  Setting the control
   bit is an administrative task that MUST be administratively
   configured on the iSNS server; iSNS clients SHALL NOT be allowed to
   change this bit using the iSNSP.

Top      Up      ToC       Page 95 
   This field MAY be used by the iSNS server to distinguish among
   permissions by different iSNS clients.  For example, an iSNS server
   implementation may be administratively configured to allow only
   targets to receive ESIs, or to permit only Control Nodes to add,
   modify, or delete discovery domains.

6.6.14.  Permanent Port Name (PPN)

   The Permanent Port Name can be used to support Fibre Channel devices
   and is consistent with the PPN description in FC-GS-4 [FC-GS-4].  The
   format of the PPN is identical to the FC Port Name WWPN attribute
   format.

6.7.  Node-Keyed Attributes

   The following attributes are registered in the iSNS database using
   the FC Node Name (WWNN) attribute as the key.  Each set of FC Node-
   Keyed attributes represents a single device and can be associated
   with many FC Ports.

   The FC Node Name is unique across the entire iSNS database.

6.7.1.  FC Node Name (WWNN)

   The FC Node Name is a 64-bit identifier that is the World Wide Node
   Name (WWNN) of the corresponding Fibre Channel device.  This
   attribute is the key for the FC Device.  This globally unique
   identifier is used during the device registration process, and it
   uses a value conforming to IEEE EUI-64 [EUI-64].

6.7.2.  Symbolic Node Name

   This is a variable-length UTF-8 encoded NULL-terminated text-based
   description of up to 256 bytes that is associated with the iSNS-
   registered FC Device in the network.

6.7.3.  Node IP Address

   This IP address is associated with the device Node in the network.
   This field is included for compatibility with Fibre Channel.  When
   this field contains an IPv4 value, it is stored as an IPv4-mapped
   IPv6 address.  That is, the most significant 10 bytes are set to
   0x00, with the next two bytes set to 0xFFFF [RFC2373].  When an IPv6
   value is contained in this field, the entire 16-byte field is used.

Top      Up      ToC       Page 96 
6.7.4.  Node IPA

   This field is the 8-byte Fibre Channel Initial Process Associator
   (IPA) associated with the device Node in the network.  The initial
   process associator is used for communication between Fibre Channel
   devices.

6.7.5.  Proxy iSCSI Name

   This is a variable-length UTF-8 encoded NULL-terminated text-based
   field that contains the iSCSI Name used to represent the FC Node in
   the IP network.  It is used as a pointer to the matching iSCSI Name
   entry in the iSNS server.  Its value is usually registered by an FC-
   iSCSI gateway connecting the IP network to the fabric containing the
   FC device.

   Note that if this field is used, there SHOULD be a matching entry in
   the iSNS database for the iSCSI device specified by the iSCSI name.
   The database entry should include the full range of iSCSI attributes
   needed for discovery and management of the "iSCSI proxy image" of the
   FC device.

6.8.  Other Attributes

   The following are not attributes of the previously-defined objects.

6.8.1.  FC-4 Type Code

   This is a 4-byte field used to provide a FC-4 type during a FC-4 Type
   query.  The FC-4 types are consistent with the FC-4 Types as defined
   in FC-FS.  Byte 0 contains the FC-4 type.  All other bytes are
   reserved.

6.8.2.  iFCP Switch Name

   The iFCP Switch Name is a 64-bit World Wide Name (WWN) identifier
   that uniquely identifies a distinct iFCP gateway in the network.
   This globally unique identifier is used during the switch
   registration/FC_DOMAIN_ID assignment process.  The iFCP Switch Name
   value used MUST conform to the requirements stated in [FC-FS] for
   World Wide Names.  The iSNS server SHALL track the state of all
   FC_DOMAIN_ID values that have been allocated to each iFCP Switch
   Name.  If a given iFCP Switch Name is deregistered from the iSNS
   database, then all FC_DOMAIN_ID values allocated to that iFCP Switch
   Name SHALL be returned to the unused pool of values.

Top      Up      ToC       Page 97 
6.8.3.  iFCP Transparent Mode Commands

6.8.3.1.  Preferred ID

   This is a 4-byte unsigned integer field, and it is the requested
   value that the iSNS client wishes to use for the FC_DOMAIN_ID.  The
   iSNS server SHALL grant the iSNS client the use of the requested
   value as the FC_DOMAIN_ID, if the requested value has not already
   been allocated.  If the requested value is not available, the iSNS
   server SHALL return a different value that has not been allocated.

6.8.3.2.  Assigned ID

   This is a 4-byte unsigned integer field that is used by an iFCP
   gateway to reserve its own unique FC_DOMAIN_ID value from the range 1
   to 239.  When a FC_DOMAIN_ID is no longer required, it SHALL be
   released by the iFCP gateway using the RlseDomId message.  The iSNS
   server MUST use the Entity Status Inquiry message to determine
   whether an iFCP gateway is still present on the network.

6.8.3.3.  Virtual_Fabric_ID

   This is a variable-length UTF-8 encoded NULL-terminated text-based
   field of up to 256 bytes.  The Virtual_Fabric_ID string is used as a
   key attribute to identify a range of non-overlapping FC_DOMAIN_ID
   values to be allocated using RqstDomId.  Each Virtual_Fabric_ID
   string submitted by an iSNS client SHALL have its own range of non-
   overlapping FC_DOMAIN_ID values to be allocated to iSNS clients.


6.9.  iSNS Server-Specific Attributes

   Access to the following attributes may be administratively
   controlled.  These attributes are specific to the iSNS server
   instance; the same value is returned for all iSNS clients accessing
   the iSNS server.  Only query messages may be performed on these
   attributes.  Attempted registrations of values for these attributes
   SHALL return a status code of 3 (Invalid Registration).

   A query for an iSNS Server-Specific attribute MUST contain the
   identifying key attribute (i.e., iSCSI Name or FC Port Name WWPN) of
   the Node originating the registration or query message as the Source
   and Message Key attributes.  The Operating Attributes are the
   server-specific attributes being registered or queried.

Top      Up      ToC       Page 98 
6.9.1.  iSNS Server Vendor OUI

   This attribute is the OUI (Organizationally Unique Identifier)
   [802-1990] identifying the specific vendor implementing the iSNS
   server. This attribute can only be queried; iSNS clients SHALL NOT be
   allowed to register a value for the iSNS Server Vendor OUI.

6.10.  Vendor-Specific Attributes

   iSNS server implementations MAY define vendor-specific attributes for
   private use.  These attributes MAY be used to store optional data
   that is registered and/or queried by iSNS clients in order to gain
   optional capabilities.  Note that any implementation of vendor-
   specific attributes in the iSNS server SHALL NOT impose any form of
   mandatory behavior on the part of the iSNS client.

   The tag values used for vendor-specific and user-specific use are
   defined in Section 6.1.  To avoid misinterpreting proprietary
   attributes, the vendor's own OUI (Organizationally Unique Identifier)
   MUST be placed in the upper three bytes of the attribute value field
   itself.

   The OUI is defined in IEEE Std 802-1990 and is the same constant used
   to generate 48 bit Universal LAN MAC addresses.  A vendor's own iSNS
   implementation will then be able to recognize the OUI in the
   attribute field and be able to execute vendor-specific handling of
   the attribute.

6.10.1.  Vendor-Specific Server Attributes

   Attributes with tags in the range 257 to 384 are vendor-specific or
   site-specific attributes of the iSNS server.  Values for these
   attributes are administratively set by the specific vendor providing
   the iSNS server implementation.  Query access to these attributes may
   be administratively controlled.  These attributes are unique for each
   logical iSNS server instance.  Query messages for these attributes
   SHALL use the key identifier (i.e., iSCSI Name or FC Port Name WWPN)
   for both the Source attribute and Message Key attribute.  These
   attributes can only be queried; iSNS clients SHALL NOT be allowed to
   register a value for server attributes.

6.10.2.  Vendor-Specific Entity Attributes

   Attributes in the range 385 to 512 are vendor-specific or site-
   specific attributes used to describe the Network Entity object.
   These attributes are keyed by the Entity Identifier attribute
   (tag=1).

Top      Up      ToC       Page 99 
6.10.3.  Vendor-Specific Portal Attributes

   Attributes in the range 513 to 640 are vendor-specific or site-
   specific attributes used to describe the Portal object.  These
   attributes are keyed by the Portal IP-Address (tag=16) and Portal
   TCP/UDP Port (tag=17).

6.10.4.  Vendor-Specific iSCSI Node Attributes

   Attributes in the range 641 to 768 are vendor-specific or site-
   specific attributes used to describe the iSCSI Node object.  These
   attributes are keyed by the iSCSI Name (tag=32).

6.10.5.  Vendor-Specific FC Port Name Attributes

   Attributes in the range 769 to 896 are vendor-specific or site-
   specific attributes used to describe the N_Port Port Name object.
   These attributes are keyed by the FC Port Name WWPN (tag=64).

6.10.6.  Vendor-Specific FC Node Name Attributes

   Attributes in the range 897 to 1024 are vendor-specific or site-
   specific attributes used to describe the FC Node Name object.  These
   attributes are keyed by the FC Node Name WWNN (tag=96).

6.10.7.  Vendor-Specific Discovery Domain Attributes

   Attributes in the range 1025 to 1280 are vendor-specific or site-
   specific attributes used to describe the Discovery Domain object.
   These attributes are keyed by the DD_ID (tag=104).

6.10.8.  Vendor-Specific Discovery Domain Set Attributes

   Attributes in the range 1281 to 1536 are vendor-specific or site-
   specific attributes used to describe the Discovery Domain Set object.
   These attributes are keyed by the DD Set ID (tag=101)

6.10.9.  Other Vendor-Specific Attributes

   Attributes in the range 1537 to 2048 can be used for key and non-key
   attributes that describe new vendor-specific objects specific to the
   vendor's iSNS server implementation.

Top      Up      ToC       Page 100 
6.11.  Discovery Domain Registration Attributes

6.11.1.  DD Set ID Keyed Attributes

6.11.1.1.  Discovery Domain Set ID (DDS ID)

   The DDS ID is an unsigned non-zero integer identifier used in the
   iSNS directory database as a key to indicate a Discovery Domain Set
   uniquely.  A DDS is a collection of Discovery Domains that can be
   enabled or disabled by a management station.  This value is used as a
   key for DDS attribute queries.  When a Discovery Domain is
   registered, it is initially not in any DDS.

   If the iSNS client does not provide a DDS_ID in a DDS registration
   request message, the iSNS server SHALL generate a DDS_ID value that
   is unique within the iSNS database for that new DDS.  The created DDS
   ID SHALL be returned in the response message.  The DDS ID value of 0
   is reserved, and the DDS ID value of 1 is used for the default DDS
   (see Section 2.2.2).

6.11.1.2.  Discovery Domain Set Symbolic Name

   A variable-length UTF-8 encoded NULL-terminated text-based field of
   up to 256 bytes.  This is a user-readable field used to assist a
   network administrator in tracking the DDS function.  When a client
   registers a DDS symbolic name, the iSNS server SHALL verify it is
   unique.  If the name is not unique, then the DDS registration SHALL
   be rejected with an "Invalid Registration" Status Code.  The invalid
   attribute(s), in this case the DDS symbolic name, SHALL be included
   in the response.

6.11.1.3.  Discovery Domain Set Status

   The DDS_Status field is a 32-bit bitmap indicating the status of the
   DDS.  Bit 0 of the bitmap indicates whether the DDS is Enabled (1) or
   Disabled (0).  The default value for the DDS Enabled flag is Disabled
   (0).

          Bit Position    DDS Status
          ------------    ---------
           31  (Lsb)      DDS Enabled (1) / DDS Disabled (0)
           All others     RESERVED

6.11.1.4.  Discovery Domain Set Next ID

   This is a virtual attribute containing a 4-byte integer value that
   indicates the next available (i.e., unused) Discovery Domain Set
   Index value.  This attribute may only be queried; the iSNS server

Top      Up      ToC       Page 101 
   SHALL return an error code of 3 (Invalid Registration) to any client
   that attempts to register a value for this attribute.  A Message Key
   is not required when exclusively querying for this attribute.

   The Discovery Domain Set Next Index MAY be used by an SNMP client to
   create an entry in the iSNS server.  SNMP requirements are described
   in Section 2.10.

6.11.2.  DD ID Keyed Attributes

6.11.2.1.  Discovery Domain ID (DD ID)

   The DD ID is an unsigned non-zero integer identifier used in the iSNS
   directory database as a key to identify a Discovery Domain uniquely.
   This value is used as the key for any DD attribute query.  If the
   iSNS client does not provide a DD_ID in a DD registration request
   message, the iSNS server SHALL generate a DD_ID value that is unique
   within the iSNS database for that new DD (i.e., the iSNS client will
   be registered in a new DD).  The created DD ID SHALL be returned in
   the response message.  The DD ID value of 0 is reserved, and the DD
   ID value of 1 is used for the default DD (see Section 2.2.2).

6.11.2.2.  Discovery Domain Symbolic Name

   A variable-length UTF-8 encoded NULL-terminated text-based field of
   up to 256 bytes.  When a client registers a DD symbolic name, the
   iSNS server SHALL verify it is unique.  If the name is not unique,
   then the DD registration SHALL be rejected with an "Invalid
   Registration" Status Code.  The invalid attribute(s), in this case
   the DD symbolic name, SHALL be included in the response.

6.11.2.3.  Discovery Domain Member: iSCSI Node Index

   This is the iSCSI Node Index of a Storage Node that is a member of
   the DD.  The DD may have a list of 0 to n members.  The iSCSI Node
   Index is one alternative representation of membership in a Discovery
   Domain, the other alternative being the iSCSI Name.  The Discovery
   Domain iSCSI Node Index is a 4-byte non-zero integer value.

   The iSCSI Node Index can be used to represent a DD member in
   situations where the iSCSI Name is too long to be used.  An example
   of this is when SNMP is used for management, as described in Section
   2.10.

   The iSCSI Node Index and the iSCSI Name stored as a member in a DD
   SHALL be consistent with the iSCSI Node Index and iSCSI Name
   attributes registered for the Storage Node object in the iSNS server.

Top      Up      ToC       Page 102 
6.11.2.4.  Discovery Domain Member: iSCSI Name

   A variable-length UTF-8 encoded NULL-terminated text-based field of
   up to 224 bytes.  It indicates membership for the specified iSCSI
   Storage Node in the Discovery Domain.  Note that the referenced
   Storage Node does not need to be actively registered in the iSNS
   database before the iSNS client uses this attribute.  There is no
   limit to the number of members that may be in a DD.  Membership is
   represented by the iSCSI Name of the iSCSI Storage Node.

6.11.2.5.  Discovery Domain Member: FC Port Name

   This 64-bit identifier attribute indicates membership for an iFCP
   Storage Node (FC Port) in the Discovery Domain.  Note that the
   referenced Storage Node does not need to be actively registered in
   the iSNS database before the iSNS client uses this attribute.  There
   is no limit to the number of members that may be in a DD.  Membership
   is represented by the FC Port Name (WWPN) of the iFCP Storage Node.

6.11.2.6.  Discovery Domain Member: Portal Index

   This attribute indicates membership in the Discovery Domain for a
   Portal.  It is an alternative representation for Portal membership to
   the Portal IP Address and Portal TCP/UDP Port.  The referenced Portal
   MUST be actively registered in the iSNS database before the iSNS
   client uses this attribute.

6.11.2.7.  Discovery Domain Member: Portal IP Address

   This attribute and the Portal TCP/UDP Port attribute indicate
   membership in the Discovery Domain for the specified Portal.  Note
   that the referenced Portal does not need to be actively registered in
   the iSNS database before the iSNS client uses this attribute.

6.11.2.8.  Discovery Domain Member: Portal TCP/UDP Port

   This attribute and the Portal IP Address attribute indicate
   membership in the Discovery Domain for the specified Portal.  Note
   that the referenced Portal does not need to be actively registered in
   the iSNS database before the iSNS client uses this attribute.

6.11.2.9.  Discovery Domain Features

   The Discovery Domain Features is a bitmap indicating the features of
   this DD.  The bit positions are defined below.  A bit set to 1
   indicates the DD has the corresponding characteristics.

Top      Up      ToC       Page 103 
          Bit Position     DD Feature
          ------------     ----------
           31 (Lsb)        Boot List Enabled (1)/Boot List Disabled (0)
           All others      RESERVED

   Boot List: this feature indicates that the target(s) in this DD
   provides boot capabilities for the member initiators, as described in
   [iSCSI-boot].

6.11.2.10.  Discovery Domain Next ID

   This is a virtual attribute containing a 4-byte integer value that
   indicates the next available (i.e., unused) Discovery Domain Index
   value.  This attribute may only be queried; the iSNS server SHALL
   return an error code of 3 (Invalid Registration) to any client that
   attempts to register a value for this attribute.  A Message Key is
   not required when exclusively querying for this attribute.



(page 103 continued on part 5)

Next RFC Part