Cisco Nexus 6000 Series NX-OS SAN Switching Configuration Guide, Release 7.x
Managing FLOGI, Name Server, FDMI, and RSCN Databases
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Managing FLOGI, Name Server, FDMI, and RSCN Databases

Contents

Managing FLOGI, Name Server, FDMI, and RSCN Databases

This chapter describes how to configure and manage FLOGI, name server FDMI, and RSCN databases.

This chapter includes the following sections:

Managing FLOGI, Name Server, FDMI, and RSCN Databases

Fabric Login

In a Fibre Channel fabric, each host or disk requires an FC ID. Use the show flogi command to verify if a storage device is displayed in the fabric login (FLOGI) table as in the following examples. If the required device is displayed in the FLOGI table, the fabric login is successful. Examine the FLOGI database on a switch that is directly connected to the host HBA and connected ports.

This example shows how to verify the storage devices in the fabric login (FLOGI) table:

switch# show flogi database
---------------------------------------------------------------------------
INTERFACE  VSAN    FCID            PORT NAME               NODE NAME
---------------------------------------------------------------------------
vfc23      1     0xb200e2  21:00:00:04:cf:27:25:2c  20:00:00:04:cf:27:25:2c
vfc23      1     0xb200e1  21:00:00:04:cf:4c:18:61  20:00:00:04:cf:4c:18:61
vfc23      1     0xb200d1  21:00:00:04:cf:4c:18:64  20:00:00:04:cf:4c:18:64
vfc23      1     0xb200ce  21:00:00:04:cf:4c:16:fb  20:00:00:04:cf:4c:16:fb
vfc23      1     0xb200cd  21:00:00:04:cf:4c:18:f7  20:00:00:04:cf:4c:18:f7
vfc31     2     0xb30100  10:00:00:05:30:00:49:63  20:00:00:05:30:00:49:5e
Total number of flogi = 6.

This example shows how to verify the storage devices attached to a specific interface:

switch# show flogi database interface vfc1/1
INTERFACE  VSAN    FCID            PORT NAME               NODE NAME 
---------------------------------------------------------------------------
vfc1/1     1     0x870000  20:00:00:1b:21:06:58:bc  10:00:00:1b:21:06:58:bc     
Total number of flogi = 1.

This example shows how to verify the storage devices associated with VSAN 1:

switch# show flogi database vsan 1

Name Server Proxy

The name server functionality maintains a database that contains the attributes for all hosts and storage devices in each VSAN. Name servers allow a database entry to be modified by a device that originally registered the information.

The proxy feature is useful when you need to modify (update or delete) the contents of a database entry that was previously registered by a different device.

All name server registration requests come from the same port whose parameter is registered or changed. If it does not, then the request is rejected.

This authorization enables WWNs to register specific parameters for another node.

About Registering Name Server Proxies

All name server registration requests come from the same port whose parameter is registered or changed. If it does not, then the request is rejected.

This authorization enables WWNs to register specific parameters for another node.

Registering Name Server Proxies

You can register the name server proxy.

Procedure
     Command or ActionPurpose
    Step 1configure terminal


    Example:
    switch# configure terminal
    switch(config)#
     

    Enters global configuration mode.

     
    Step 2 fcns proxy-port wwn-id vsan vsan-id


    Example:
    switch(config)# fcns proxy-port 11:22:11:22:33:44:33:44 vsan 300
     

    Configures a proxy port for the specified VSAN.

     

    Rejecting Duplicate pWWNs

    You can prevent malicious or accidental log in using another device’s pWWN by enabling the reject-duplicate-pwwn option. If you disable this option, these pWWNs are allowed to log in to the fabric and replace the first device in the name server database.

    Rejecting Duplicate pWWNs

    You can reject duplicate pWWNs.

    Procedure
       Command or ActionPurpose
      Step 1configure terminal


      Example:
      switch# configure terminal
      switch(config)#
       

      Enters global configuration mode.

       
      Step 2 fcns reject-duplicate-pwwn vsan vsan-id


      Example:
      switch(config)# fcns reject-duplicate-pwwn vsan 100
       

      Logs out devices when they log into the fabric if the pWWNs already exist.

       
      Step 3 no fcns reject-duplicate-pwwn vsan vsan-id


      Example:
      switch(config)# no fcns reject-duplicate-pwwn vsan 256
       

      Overwrites the first device’s entry in the name server database with the new device having the same pWWN (default).

       

      Name Server Database Entries

      The name server stores name entries for all hosts in the FCNS database. The name server permits an Nx port to register attributes during a PLOGI (to the name server) to obtain attributes of other hosts. These attributes are deregistered when the Nx port logs out either explicitly or implicitly.

      In a multiswitch fabric configuration, the name server instances running on each switch shares information in a distributed database. One instance of the name server process runs on each switch.

      Displaying Name Server Database Entries

      This example shows how to display the name server database for all VSANs:

      switch# show fcns database
      
      --------------------------------------------------------------------------
      FCID        TYPE  PWWN                    (VENDOR)        FC4-TYPE:FEATURE
      --------------------------------------------------------------------------
      0x010000    N     50:06:0b:00:00:10:a7:80                   scsi-fcp fc-gs 
      0x010001    N     10:00:00:05:30:00:24:63 (Cisco)           ipfc 
      0x010002    N     50:06:04:82:c3:a0:98:52 (Company 1)       scsi-fcp 250 
      0x010100    N     21:00:00:e0:8b:02:99:36 (Company A)       scsi-fcp 
      0x020000    N     21:00:00:e0:8b:08:4b:20 (Company A)
      0x020100    N     10:00:00:05:30:00:24:23 (Cisco)           ipfc 
      0x020200    N     21:01:00:e0:8b:22:99:36 (Company A)       scsi-fcp 

      This example shows how to display the name server database and statistical information for a specified VSAN:

      switch# show fcns database vsan 1
      
      VSAN 1:
      --------------------------------------------------------------------------
      FCID        TYPE  PWWN                    (VENDOR)        FC4-TYPE:FEATURE
      --------------------------------------------------------------------------
      0x030001    N     10:00:00:05:30:00:25:a3 (Cisco)         ipfc
      0x030101    NL    10:00:00:00:77:99:60:2c (Interphase)
      0x030200    N     10:00:00:49:c9:28:c7:01
      0xec0001    NL    21:00:00:20:37:a6:be:14 (Seagate)       scsi-fcp
      Total number of entries = 4

      This example shows how to display the name server database details for all VSANs:

      switch# show fcns database detail
      

      This example shows how to display the name server database statistics for all VSANs:

      switch# show fcns statistics
      

      FDMI

      Cisco SAN switches provide support for the Fabric-Device Management Interface (FDMI) functionality, as described in the FC-GS-4 standard. FDMI enables management of devices such as Fibre Channel host bus adapters (HBAs) through in-band communications. This addition complements the existing Fibre Channel name server and management server functions.

      Using the FDMI functionality, the switch software can extract the following management information about attached HBAs and host operating systems without installing proprietary host agents:

      • Manufacturer, model, and serial number
      • Node name and node symbolic name
      • Hardware, driver, and firmware versions
      • Host operating system (OS) name and version number

      All FDMI entries are stored in persistent storage and are retrieved when the FDMI process is started.

      Displaying FDMI

      This example shows how to display all HBA details for a specified VSAN:

      switch# show fdmi database detail vsan 1
      

      RSCN

      The Registered State Change Notification (RSCN) is a Fibre Channel service that informs hosts about changes in the fabric. Hosts can receive this information by registering with the fabric controller (through a State Change Registration (SCR) request). These notifications provide a timely indication of one or more of the following events:

      • Disks joining or leaving the fabric
      • A name server registration change
      • A new zone enforcement
      • IP address change
      • Any other similar event that affects the operation of the host

      A switch RSCN (SW-RSCN) is sent to registered hosts and to all reachable switches in the fabric.


      Note


      The switch sends an RSCN to notify registered nodes that a change has occurred. It is up to the nodes to query the name server again to obtain the new information. The details of the changed information are not delivered by the switch in the RSCN sent to the nodes.


      About RSCN Information

      A switch RSCN (SW-RSCN) is sent to registered hosts and to all reachable switches in the fabric.


      Note


      The switch sends an RSCN to notify registered nodes that a change has occurred. It is up to the nodes to query the name server again to obtain the new information. The details of the changed information are not delivered by the switch in the RSCN sent to the nodes.


      Displaying RSCN Information

      The following example shows how to display registered device information:

      switch# show rscn scr-table vsan 1
      

      Note


      The SCR table is not configurable. It is populated when hosts send SCR frames with RSCN information. If hosts do not receive RSCN information, then the show rscn scr-table command will not return entries.


      Multi-pid Option

      If the RSCN multi-pid option is enabled, RSCNs generated to the registered Nx ports might contain more than one affected port IDs. In this case, zoning rules are applied before putting the multiple affected port IDs together in a single RSCN. By enabling this option, you can reduce the number of RSCNs. For example, you have two disks (D1, D2) and a host (H) connected to switch 1. Host H is registered to receive RSCNs. D1, D2, and H belong to the same zone. If disks D1 and D2 are online at the same time, one of the following actions applies:

      • The multi-pid option is disabled on switch 1— Two RSCNs are generated to host H: one for the disk D1 and another for disk D2.
      • The multi-pid option is enabled on switch 1—A single RSCN is generated to host H, and the RSCN payload lists the affected port IDs (in this case, both D1 and D2).

      Note


      Some Nx ports may not support multi-pid RSCN payloads. If so, disable the RSCN multi-pid option.


      Configuring the multi-pid Option

      You can configure the multi-pid option.

      Procedure
         Command or ActionPurpose
        Step 1configure terminal


        Example:
        switch# configure terminal
        switch(config)#
         

        Enters global configuration mode.

         
        Step 2 rscn multi-pid vsan vsan-id


        Example:
        switch(config)# rscn multi-pid vsan 405
         

        Sends RSCNs in a multi-pid format for the specified VSAN.

         

        Suppressing Domain Format SW-RSCNs

        A domain format SW-RSCN is sent whenever the local switch name or the local switch management IP address changes. This SW-RSCN is sent to all other domains and switches over the ISLs. The remote switches can issue GMAL and GIELN commands to the switch that initiated the domain format SW-RSCN to determine what changed. Domain format SW-RSCNs can cause problems with some non-Cisco SAN switches.

        You can suppress the transmission of these SW-RSCNs over an ISL.

        Procedure
           Command or ActionPurpose
          Step 1configure terminal


          Example:
          switch# configure terminal
          switch(config)#
           

          Enters global configuration mode.

           
          Step 2 rscn suppress domain-swrscn vsan vsan-id


          Example:
          switch(config)# rscn suppress domain-swrscn vsan 250
           

          Suppresses transmission of domain format SW-RSCNs for the specified VSAN.

           

          Clearing RSCN Statistics

          You can clear the counters and later view the counters for a different set of events. For example, you can keep track of how many RSCNs or SW-RSCNs are generated on a particular event (such as ONLINE or OFFLINE events). You can use these statistics to monitor responses for each event in the VSAN.

          This example shows how to clear the RSCN statistics for the specified VSAN:

          switch# clear rscn statistics vsan 1
          

          After clearing the RSCN statistics, you can view the cleared counters by entering the show rscn statistics command:

          switch# show rscn statistics vsan 1
          

          Configuring the RSCN Timer

          RSCN maintains a per VSAN event list queue, where the RSCN events are queued as they are generated. When the first RSCN event is queued, a per VSAN timer starts. When a timeout occurs, all the events are dequeued and coalesced RSCNs are sent to registered users. The default timer values minimize the number of coalesced RSCNs that are sent to registered users. Some deployments require smaller event timer values to track changes in the fabric.


          Note


          The RSCN timer value must be the same on all switches in the VSAN.



          Note


          Before performing a downgrade, make sure that you revert the RSCN timer value in your network to the default value. Failure to do so will disable the links across your VSANs and other devices.


          You can configure the RSCN timer.

          Procedure
             Command or ActionPurpose
            Step 1configure terminal


            Example:
            switch# configure terminal
            switch(config)#
             

            Enters global configuration mode.

             
            Step 2 rscn distribute


            Example:
            switch(config)# rscn distribute
             

            Enables RSCN timer configuration distribution.

             
            Step 3 rscn event-tov timeout vsan vsan-id


            Example:
            switch(config)# rscn event-tov 1000 vsan 501
             

            Sets the event time-out value in milliseconds for the specified VSAN. The range is 0 to 2000 milliseconds. Setting a zero (0) value disables the timer.

             
            Step 4 no rscn event-tov timeout vsan vsan-id


            Example:
            switch(config)# no rscn event-tov 1100 vsan 245
             

            Reverts to the default value (2000 milliseconds for Fibre Channel VSANs).

             
            Step 5 rscn commit vsan vsan-id


            Example:
            switch(config)# rscn commit vsan 25
             

            Commits the RSCN timer configuration to be distributed to the switches in the specified VSAN.

             

            Verifying the RSCN Timer Configuration

            You verify the RSCN timer configuration using the show rscn event-tov vsan command. This example shows how to clear the RSCN statistics for VSAN 10:

            switch# show rscn event-tov vsan 10
            
            Event TOV : 1000 ms

            RSCN Timer Configuration Distribution

            Because the timeout value for each switch is configured manually, a misconfiguration occurs when different switches time out at different times. Different N-ports in a network can receive RSCNs at different times. Cisco Fabric Services (CFS) infrastructure alleviates this situation by automatically distributing the RSCN timer configuration information to all switches in a fabric, which also reduces the number of SW-RSCNs.

            RSCN supports two modes, distributed and nondistributed. In distributed mode, RSCN uses Cisco Fabric Services (CFS) to distribute configuration to all switches in the fabric. In nondistributed mode, only the configuration commands on the local switch are affected.


            Note


            All configuration commands are not distributed. Only the rscn event-tov tov vsan vsan command is distributed.



            Caution


            Only the RSCN timer configuration is distributed.


            The RSCN timer is registered with CFS during initialization and switchover. For high availability, if the RSCN timer distribution crashes and restarts or a switchover occurs, it resumes normal functionality from the state prior to the crash or switchover.

            For additional information, refer to Using Cisco Fabric Services in the System Management Configuration Guide for your device.

            Enabling RSCN Timer Configuration Distribution

            You can enable RSCN timer configuration distribution.

            Procedure
               Command or ActionPurpose
              Step 1configure terminal


              Example:
              switch# configure terminal
              switch(config)#
               

              Enters global configuration mode.

               
              Step 2 rscn distribute


              Example:
              switch(config)# rscn distribute
               

              Enables RSCN timer distribution.

               
              Step 3 no rscn distribute


              Example:
              switch(config)# no rscn distribute
               

              Disables (default) RSCN timer distribution.

               

              Locking the Fabric

              The first action that modifies the database creates the pending database and locks the feature in the VSAN. Once you lock the fabric, the following situations apply:

              • No other user can make any configuration changes to this feature.
              • A copy of the configuration database becomes the pending database along with the first active change.

              Committing RSCN Timer Configuration Changes

              If you commit the changes made to the active database, the configuration is committed to all the switches in the fabric. On a successful commit, the configuration change is applied throughout the fabric and the lock is released.

              You can commit RSCN timer configuration changes.

              Procedure
                 Command or ActionPurpose
                Step 1configure terminal


                Example:
                switch# configure terminal
                switch(config)#
                 

                Enters global configuration mode.

                 
                Step 2 rscn commit vsan timeout


                Example:
                switch(config)# rscn commit vsan 500
                 

                Commits the RSCN timer changes.

                 

                Discarding the RSCN Timer Configuration Changes

                If you discard (abort) the changes made to the pending database, the configuration database remains unaffected and the lock is released.

                You can discard RSCN timer configuration changes.

                Procedure
                   Command or ActionPurpose
                  Step 1configure terminal


                  Example:
                  switch# configure terminal
                  switch(config)#
                   

                  Enters global configuration mode.

                   
                  Step 2 rscn abort vsan timeout


                  Example:
                  switch(config)# rscn abort vsan 800
                   

                  Discards the RSCN timer changes and clears the pending configuration database.

                   

                  Clearing a Locked Session

                  If you have changed the RSCN timer configuration and have forgotten to release the lock by either committing or discarding the changes, an administrator can release the lock from any switch in the fabric. If the administrator performs this task, your changes to the pending database are discarded and the fabric lock is released.

                  The pending database is only available in the volatile directory and are subject to being discarded if the switch is restarted.

                  To use administrative privileges and release a locked DPVM session, use the clear rscn session vsan command in EXEC mode. This example shows how to clear the RSCN session for VSAN 10:

                  switch# clear rscn session vsan 10
                  

                  Displaying RSCN Configuration Distribution Information

                  This example shows how to display the registration status for RSCN configuration distribution:

                  switch# show cfs application name rscn
                  
                   Enabled        : Yes
                   Timeout        : 5s
                   Merge Capable  : Yes
                   Scope          : Logical

                  Note


                  A merge failure results when the RSCN timer values are different on the merging fabrics.


                  This example shows how to display the set of configuration commands that would take effect when you commit the configuration:


                  Note


                  The pending database includes both existing and modified configuration.


                  switch# show rscn pending
                  
                  rscn event-tov 2000 ms vsan 1
                  rscn event-tov 2000 ms vsan 2
                  rscn event-tov 300 ms vsan 10

                  This example shows how to display the difference between pending and active configurations:

                  switch# show rscn pending-diff vsan 10
                  
                  - rscn event-tov 2000 ms vsan 10
                  + rscn event-tov 300 ms vsan 10

                  Default Settings for RSCN

                  The following table lists the default settings for RSCN.

                  Table 1  Default RSCN Settings

                  Parameters

                  Default

                  RSCN timer value

                  2000 milliseconds for Fibre Channel VSANs

                  RSCN timer configuration distribution

                  Disabled