Cisco Nexus 7000 Series NX-OS SAN Switching Configuration Guide
IVR NAT and Auto Topology
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IVR NAT and Auto Topology

IVR NAT and Auto Topology

Information About IVR Auto Topology

IVR uses a configured IVR VSAN topology to determine how to route traffic between the initiator and the target across the fabric. IVR auto topology mode automatically builds the IVR VSAN topology and maintains the topology database when fabric reconfiguration occur. IVR auto topology mode also distributes the IVR VSAN topology to IVR-enabled switches using CFS.

Using IVR auto topology mode, you do not need to manually update the IVR VSAN topology when reconfiguration occur in your fabric. If an IVR manual topology database exists, IVR auto topology mode initially uses that topology information. The automatic update reduces disruption in the network by gradually migrating from the user-specified topology database to the automatically-learned topology database. User-configured topology entries that are not part of the network are aged out in about three minutes. New entries that are not part of the user-configured database are added as they are discovered in the network.

When IVR auto topology mode is enabled, it starts with the previously active IVR manual topology if it exists, and then the discovery process begins. New, alternate, or better paths may be discovered. If the traffic is switched to an alternate or better path, there may be temporary traffic disruptions that are normally associated with switching paths.

Before configuring an IVR SAN fabric to use IVR NAT and IVR auto topology mode, consider the following:

  • Configure IVR only in the relevant switches.
  • Enable CFS for IVR on all switches in the fabric.

Tip


If you change any FSPF link cost, ensure that the FSPF path distance (that is, the sum of the link costs on the path) of any IVR path is less than 30,000.



Note


IVR-enabled VSANs can be configured when the interop mode is enabled (any interop mode) or disabled (no interop mode).


IVR Network Address Translation

IVR Network Address Translation (NAT) can be enabled to allow non-unique domain IDs; however, without NAT, IVR requires unique domain IDs for all switches in the fabric. IVR NAT simplifies the deployment of IVR in an existing fabric where non-unique domain IDs might be present.

To use IVR NAT, you must enable it on all IVR-enabled switches in the fabric.

Default Settings

Parameters Default
IVR feature Disabled
IVR NAT Disabled
IVR distribution Disabled
IVR Autotopology Disabled
IVR VSANs Not added to virtual domains
QoS for IVR Zones Low

Licensing Requirements

Product License
Cisco Nexus 7000 Series. IVR requires the FCoE license for each F-series module. FCoE enabled in a storage VDC does not require the Advanced Services License.

IVR also requires the Storage Enterprise License.

For a complete explanation of the Cisco NX-OS licensing scheme and how to obtain and apply licenses, see the Cisco NX-OS Licensing Guide.

Guidelines and Limitations for IVR NAT and Autotopology

  • IVR NAT port login (PLOGI) requests that are received from hosts are delayed a few seconds to perform the rewrite on the FC ID address. If the host’s PLOGI timeout value is set to a value less than five seconds, it may result in the PLOGI being unnecessarily aborted and the host being unable to access the target. We recommend that you configure the host bus adapter for a timeout of at least ten seconds (most HBAs default to a value of 10 or 20 seconds).
  • Load balancing of IVR NAT traffic across equal cost paths from an IVR-enabled switch is not supported.
  • IVR NAT allows you to set up IVR in a fabric without needing unique domain IDs on every switch in the IVR path. IVR NAT virtualizes the switches in other VSANs by using local VSAN for the destination IDs in the Fibre Channel headers. In some Extended Link Service message types, the destination IDs are included in the packet data. In these cases, IVR NAT replaces the actual destination ID with the virtualized destination ID. IVR NAT supports destination ID replacement in the Extended Link Service messages.
  • If you have a message that is not recognized by IVR NAT and contains the destination ID in the packet data, you cannot use IVR with NAT in your topology. You can still use IVR with unique domain IDs.

The following table lists the Extended Link Service messages supported by IVR NAT:

Extended Link Service Messages Link Service Command (LS_COMMAND) Mnemonic
Abort Exchange 0x06 00 00 00 ABTX
Discover Address 0x52 00 00 00 ADISC
Discover Address Accept 0x02 00 00 00 ADISC ACC
Fibre Channel Address Resolution Protocol Reply 0x55 00 00 00 FARP-REPLY
Fibre Channel Address Resolution Protocol Request 0x54 00 00 00 FARP-REQ
Logout 0x05 00 00 00 LOGO
Port Login 0x30 00 00 00 PLOGI
Read Exchange Concise 0x13 00 00 00 REC
Read Exchange Concise Accept 0x02 00 00 00 REC ACC
Read Exchange Status Block 0x08 00 00 00 RES
Read Exchange Status Block Accept 0x02 00 00 00 RES ACC
Read Link Error Status Block 0x0F 00 00 00 RLS
Read Sequence Status Block 0x09 00 00 00 RSS
Reinstate Recovery Qualifier 0x12 00 00 00 RRQ
Request Sequence Initiative 0x0A 00 00 00 RSI
Scan Remote Loop 0x7B 00 00 00 RSL
Third Party Process Logout 0x24 00 00 00 TPRLO
Third Party Process Logout Accept 0x02 00 00 00 TPRLO ACC

Transit VSAN Guidelines

Consider the following guidelines for transit VSANs:

  • In addition to defining the IVR zone membership, you can choose to specify a set of transit VSANs to provide connectivity between two edge VSANs:
    • If two edge VSANs in an IVR zone overlap, then a transit VSAN is not required (though, not prohibited) to provide connectivity.
    • If two edge VSANs in an IVR zone do not overlap, you may need one or more transit VSANs to provide connectivity. Two edge VSANs in an IVR zone will not overlap if IVR is not enabled on a switch that is a member of both the source and destination edge VSANs.
  • Traffic between the edge VSANs only traverses through the shortest IVR path.
  • Transit VSAN information is common to all IVR zone sets. Sometimes, a transit VSAN can also act as an edge VSAN in another IVR zone.

Border Switch Guidelines

  • A border switch must be a member of two or more VSANs.
  • A border switch that facilitates IVR communications must be IVR-enabled.
  • IVR can (optionally) be enabled on additional border switches to provide redundant paths between active IVR zone members.
  • The VSAN topology configuration updates automatically when a border switch is added or removed.

Configuring IVR NAT and Autotopology

Enabling IVR NAT

Before You Begin
  • Ensure you have enabled the IVR feature and IVR distribution.
SUMMARY STEPS

    1.    configure terminal

    2.    ivr nat

    3.    (Optional) show ivr

    4.    (Optional) copy running-config startup-config


DETAILED STEPS
      Command or Action Purpose
    Step 1 configure terminal


    Example:
    switch# configure terminal
    switch(config)#
     

    Enters global configuration mode.

     
    Step 2 ivr nat


    Example:
    switch(config)# ivr nat
     

    Enables IVR NAT.

     
    Step 3 show ivr


    Example:
    switch(config)# show ivr
     
    (Optional)

    Displays information about IVR.

     
    Step 4 copy running-config startup-config


    Example:
    switch(config)# copy running-config startup-config
     
    (Optional)

    Copies the running configuration to the startup configuration.

     

    Enabling IVR Auto Topology

    Before You Begin
    • Ensure you have enabled the IVR feature and IVR distribution.
    SUMMARY STEPS

      1.    configure terminal

      2.    ivr vsan-topology auto

      3.    (Optional) show ivr vsan topology

      4.    (Optional) copy running-config startup-config


    DETAILED STEPS
        Command or Action Purpose
      Step 1 configure terminal


      Example:
      switch# configure terminal
      switch(config)#
       

      Enters global configuration mode.

       
      Step 2 ivr vsan-topology auto


      Example:
      switch(config)# ivr vsan-topology auto
       

      Enables IVR auto topology mode.

       
      Step 3 show ivr vsan topology


      Example:
      switch(config)# show ivr vsan topology
       
      (Optional)

      Displays the automatically discovered IVR topology and the topology mode.

       
      Step 4 copy running-config startup-config


      Example:
      switch(config)# copy running-config startup-config
       
      (Optional)

      Copies the running configuration to the startup configuration.

       

      Verifying IVR Configuration

      To display the IVR configuration, perform one of the following tasks:

      Command

      Purpose

      show ivr

      Displays the status for the IVR configuration.

      show ivr diagnostics

      Displays information about IVR diagnostics.

      show ivr merge status

      Displays information the last IVR merge event.

      show ivr pending

      Displays information about the IVR pending database.

      show ivr pending-diff

      Displays the differences between the pending database and the config database.

      show ivr vsan-topology [active | configured]

      Displays the IVR VSAN topology.

      show ivr session status

      Displays information about IVR CFS session.

      show ivr virtual-domains

      Displays information about IVR virtual domains for all local VSANs.

      show ivr zone

      Displays information about IVR zones.

      show ivr zoneset

      Displays information about IVR zone sets.

      show ivr service-group active

      Displays information about the active service group.
      show ivr service-group configured Displays information about the configured service group.
      show autonomous-fabric-id database Displays information about the AFIDs.
      show ivr virtual-fcdomain-add-status Displays the status of the IVR virtual domain configuration.

      Example: IVR Auto Topology


        Step 1   Enable IVR on every border switch in the fabric.

        Example:
        switch# config t
        Enter configuration commands, one per line.  End with CNTL/Z.
        switch(config)# feature ivr
        switch(config)# exit
        switch#
        Step 2   Verify that IVR is enabled on every IVR-enabled switch.

        Example:
        switch# show ivr
        Inter-VSAN Routing is enabled
        
        Inter-VSAN enabled switches
        ---------------------------
        No IVR-enabled VSAN is active. Check VSAN-Topology configuration.
        
        Inter-VSAN topology status
        --------------------------
        Current Status: Inter-VSAN topology is INACTIVE
        
        Inter-VSAN zoneset status
        -------------------------
            name               : 
            state              : idle
            last activate time : 
        
        Fabric distribution status
        -----------------------
        fabric distribution disabled
        Last Action                : None
        Last Action Result         : None
        Last Action Failure Reason : None
        
        Inter-VSAN NAT mode status
        --------------------------
        FCID-NAT is disabled
        
        License status
        -----------------
        IVR is running based on the following license(s)
        ENTERPRISE_PKG
        
        
        Step 3   Enable CFS distribution on every IVR-enabled switch in the fabric.

        Example:
        switch# config t
        Enter configuration commands, one per line. End with CNTL/Z.
        switch(config)# ivr distribution
        
        
        Step 4   Enable IVR auto topology mode.

        Example:
        switch(config)# ivr vsan-topology auto
        fabric is locked for configuration. Please commit after configuration is 
        done.
        
        
        Step 5   Commit the change to the fabric.

        Example:
        switch(config)# ivr commit
        switch(config)# exit
        switch#
        
        
        Step 6   Verify the status of the commit request.

        Example:
        switch# show ivr session status
        Last Action                : Commit
        Last Action Result         : Success
        Last Action Failure Reason : None
        
        
        Step 7   Verify the active IVR auto topology.

        Example:
        switch# show ivr vsan-topology active
        
        AFID  SWITCH WWN                 Active   Cfg. VSANS
        --------------------------------------------------------------
           1  20:00:00:0d:ec:08:6e:40 *  yes      no   1,336-338 
           1  20:00:00:0d:ec:0c:99:40    yes      no   336,339 
        
        
        
        Step 8   Configure IVR zone set and zones.

        Example:
        switch(config)# ivr zoneset name tape_server1_server2
        
        switch(config-ivr-zoneset)# zone name tape_server1
        switch(config-ivr-zoneset-zone)# member pwwn 10:02:50:45:32:20:7a:52 vsan 1
        switch(config-ivr-zoneset-zone)# member pwwn 10:02:66:45:00:20:89:04 vsan 2
        switch(config-ivr-zoneset-zone)# exit
        
        switch(config-ivr-zoneset)# zone name tape_server2
        switch(config-ivr-zoneset-zone)# member pwwn 10:02:50:45:32:20:7a:52 vsan 1
        switch(config-ivr-zoneset-zone)# member pwwn 10:00:ad:51:78:33:f9:86 vsan 3
        switch(config-ivr-zoneset-zone)# exit
        
        
        
        Two zones are required:
        • One zone has tape T (pwwn 10:02:50:45:32:20:7a:52) and server S1 (pwwn 10:02:66:45:00:20:89:04).
        • Another zone has tape T and server S2 (pwwn 10:00:ad:51:78:33:f9:86).
        Tip   

        Instead of creating two IVR zones, you can also create one IVR zone with the tape and both servers.

        Step 9   View the IVR zone configuration to confirm that the IVR zone set and IVR zones are properly configured.

        Example:
        switch(config)# show ivr zoneset
        zoneset name tape_server1_server2
          zone name tape_server1
              pwwn 10:02:50:45:32:20:7a:52 vsan 1    
              pwwn 10:02:66:45:00:20:89:04 vsan 2    
        
          zone name tape_server2
              pwwn 10:02:50:45:32:20:7a:52 vsan 1    
              pwwn 10:00:ad:51:78:33:f9:86 vsan 3 
        
        
        Step 10   View the zone set prior to IVR zone set activation. Prior to activating the IVR zone set, view the active zone set. Repeat this step for VSANs 2 and 3.

        Example:
        switch(config)# show zoneset active vsan 1
        zoneset name finance_dept vsan 1
          zone name accounts_database vsan 1
            pwwn 10:00:23:11:ed:f6:23:12
            pwwn 10:00:56:43:11:56:fe:ee
            
          zone name $default_zone$ vsan 1
        
        
        Step 11   Activate the configured IVR zone set.

        Example:
        switch(config)# ivr zoneset activate name tape_server1_server2
        zoneset activation initiated. check inter-VSAN zoneset status
        switch(config)# exit
        switch#
        
        
        Step 12   Verify the IVR zone set activation.

        Example:
        switch# show ivr zoneset active 
        zoneset name tape_server1_server2
          zone name tape_server1
              pwwn 10:02:50:45:32:20:7a:52 vsan 1
              pwwn 10:02:66:45:00:20:89:04 vsan 2
        
          zone name tape_server2
              pwwn 10:02:50:45:32:20:7a:52 vsan 1
              pwwn 10:00:ad:51:78:33:f9:86 vsan 3
        
        
        Step 13   Verify the zone set updates. Upon successful IVR zone set activation, verify that appropriate zones are added to the active zone set. Repeat this step for VSANs 2 and 3.

        Example:
        switch# show zoneset active vsan 1
        zoneset name finance_dept vsan 1
          zone name accounts_database vsan 1
            pwwn 10:00:23:11:ed:f6:23:12
            pwwn 10:00:56:43:11:56:fe:ee
          
          zone name IVRZ_tape_server1 vsan 1
            pwwn 10:02:66:45:00:20:89:04
            pwwn 10:02:50:45:32:20:7a:52
          
          zone name IVRZ_tape_server2 vsan 1
            pwwn 10:02:50:45:32:20:7a:52
            pwwn 10:00:ad:51:78:33:f9:86
          
          zone name $default_zone$ vsan 1
        
        switch# show ivr zoneset status 
        Zoneset Status
        ______________
            name               : tape_server1_server2
            state              : activation success
            last activate time : Tue May 20 23:23:01 1980
            force option       : on
        
        status per vsan:
        __________________
             vsan     status    
             ____     ______    
             1        active 

        Feature History

        Table 1  Feature History IVR

        Feature Name

        Releases

        Feature Information

        IVR

        5.2(1)

        This feature was introduced.