Configuring Wireless High Availability

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http:/​​/​​www.cisco.com/​​go/​​cfn. An account on Cisco.com is not required.

Information about High Availability

The high availability feature is enabled by default when the switches are connected using the stack cable and the Cisco StackWise-160 technology is enabled. You cannot disable it; however, you can initiate a manual graceful-switchover using the command line interface to use the high availability feature enabled in the switch.

Information about Access Point Stateful Switch Over

An Access Point Stateful Switch Over (AP SSO) implies that all the access point sessions are switched over state-fully and the user session information is maintained during a switchover, and access points continue to operate in network with no loss of sessions, providing improved network availability. The active switch in the stack is equipped to perform all network functions, including IP functions and routing information exchange. The switch supports 1000 access points and 12000 clients.

However, all the clients are de-authenticated and need to be re-associated with the new active switch except for the locally switched clients in FlexConnect mode when a switchover occurs.

Once a redundancy pair is formed while in a stack, high availability is enabled, which includes that access points continue to remain connected during an active-to-standby switchover.


Note
You can not disable AP SSO while in a switch stack once the switches form a redundant pair.

Initiating Graceful Switchover

To perform a manual switchover and to use the high availability feature enabled in the switch, execute the redundancy force-switchover command. This command initiates a graceful switchover from the active to the standby switch. 

Switch# redundancy force-switchover
System configuration has been modified. Save ? [yes/no] : yes
Building configuration …
Preparing for switchover …
Compressed configuration from 14977 bytes to 6592 bytes[OK]This will reload the active unit and force switchover to standby[confirm] : y

Configuring EtherChannels

The LAG, or an EtherChannel, bundles all the existing ports in both the standby and active units into a single logical port to provide an aggregate bandwidth of 60 Gbps. The creation of an EtherChannel enables protection against failures. The EtherChannels or LAGs created are used for link redundancy to ensure high availability of access points.

    Step 1   Connect two switches that are in powered down state using the stack cable.
    Step 2   Power up and perform a boot on both switches simultaneously or power and boot one switch.

    The switches boot up successfully, and form a high availability pair.

    Step 3   Configure EtherChannel or LAG on the units.
    Step 4   Use the show etherchannel summary command to view the status of the configured EtherChannel.

    On successful configuration, all the specified ports will be bundled in a single channel and listed in the command output of show etherchannel summary.

    Step 5   Execute the show ap uptime command to verify the connected access points.

    Configuring LACP

    SUMMARY STEPS

      1.    configure terminal

      2.    interface port-channel number

      3.    lacp max-bundle number

      4.    lacp port-priority number

      5.    switchport backup interface po2

      6.    end

      7.    show etherchannel summary

      8.    show interfaces switchport backup


    DETAILED STEPS
       Command or ActionPurpose
      Step 1configure terminal


      Example: 
      Switch# configure terminal
              		Enters global configuration mode.  
      Step 2interface port-channel number


      Example: 
      Switch(config)# interface Port-channel Po2
              		Enters port-channel interface configuration mode.  
      Step 3 lacp max-bundle number


      Example: 
      Switch(config-if)# lacp max-bundle 6
       

      Defines the maximum number of active bundled LACP ports allowed in a port channel. The value ranges from 1 to 8.

       
      Step 4 lacp port-priority number


      Example: 
      Switch(config-if)# lacp port-priority 4
       

      Specifies port priority to be configured on the port using LACP. The value ranges from 0 to 65535.

       
      Step 5 switchport backup interface po2


      Example: 
      Switch(config-if)# switchport backup interface Po2
       

      Specifies an interface as the backup interface.

       
      Step 6end
              		Exits the interface and configuration mode.  
      Step 7 show etherchannel summary


      Example: 
      Switch# show etherchannel summary
       

      Displays a summary of EtherChannel properties.

       
      Step 8 show interfaces switchport backup


      Example: 
      Switch# show interfaces switchport backup
       

      Displays summary of backup EtherChannel properties.

       

      Troubleshooting High Availability

      Access the Standby Console

      You can only access the console of the active switch in a stack. To access the standby switch, use the following commands.

      Before You Begin

      Use this functionality only under supervision of Cisco Support.

      SUMMARY STEPS

        1.    configure terminal

        2.    service internal

        3.    redundancy

        4.    main-cpu

        5.    standby console enable

        6.    exit


      DETAILED STEPS
         Command or ActionPurpose
        Step 1configure terminal


        Example: 
        Switch# configure terminal
                  		Enters global configuration mode.  
        Step 2 service internal


        Example: 
        Switch(config)# service internal
         

        Enables Cisco IOS debug commands.

         
        Step 3redundancy


        Example: 
        Switch(config)# redundancy
         

        Enters redundancy configuration mode.

         
        Step 4main-cpu


        Example: 
        Switch(config)# main-cpu
         

        Enters the redundancy main configuration submode.

         
        Step 5standby console enable


        Example: 
        Switch(config)# standby console enable
         

        Enables the standby console.

         
        Step 6exit


        Example: 
        Switch(config)# exit
         

        Exits the configuration mode.

         

        Before a Switchover

        A switchover happens when the active switch fails; however, while performing a manual switchover, you can execute these commands to initiate a successful switchover:

        SUMMARY STEPS

          1.    show redundancy states

          2.    show switch detail

          3.    show platform ses states

          4.    show ap summary

          5.    show capwap detail

          6.    show dtls database-brief

          7.    show power inline


        DETAILED STEPS
           Command or ActionPurpose
          Step 1 show redundancy states


          Example: 
          Switch# show redundancy states
           

          Displays the high availability role of the active and standby switches.

           
          Step 2show switch detail


          Example: 
          Switch# show switch detail
           

          Display physical property of the stack. Verify if the physical states of the stacks are "Ready" or "Port".

           
          Step 3show platform ses states


          Example: 
          Switch# show platform ses states
           

          Displays the sequences of the stack manager.

           
          Step 4show ap summary


          Example: 
          Switch# show ap summary
           

          Displays all the access points in the active and standby switches.

           
          Step 5show capwap detail


          Example: 
          Switch# show capwap detail
           

          Displays the details of the CAPWAP tunnel in the active and standby switches.

           
          Step 6show dtls database-brief


          Example: 
          Switch# show dtls database-brief
           

          Displays DTLS details in the active and standby switches.

           
          Step 7show power inline


          Example: 
          Switch# show power inline
           

          Displays the power on Ethernet power state.

          Note    When a failover occurs, the standby controller must be in a standby-hot state and the redundant port in a terminal state in SSO for successful switchover to occur.
           

          After a Switchover

          This section defines the steps that you must perform to ensure that successful switchover from the active to standby switch is performed. On successful switchover of the standby switch as active, all access points connected to the active need to re-join the standby (then active) switch.

          SUMMARY STEPS

            1.    show ap uptime

            2.    show wireless summary

            3.    show wcdb database all

            4.    show power inline


          DETAILED STEPS
             Command or ActionPurpose
            Step 1show ap uptime


            Example: 
            Switch# show ap uptime
             

            Verify if the uptime of the access point after the switchover is large enough.

             
            Step 2show wireless summary


            Example: 
            Switch# show wireless summary
             

            Display the clients connected in the active switch.

             
            Step 3show wcdb database all


            Example: 
            Switch# show wcdb database all
             

            Display if the client has reached the uptime.

             
            Step 4show power inline


            Example: 
            Switch# show power inline
             

            Display the power over Ethernet power state.

             

            Monitoring the Switch Stack

            Table 1 Commands for Displaying Stack Information

            Command

            Description

            show switch

            Displays summary information about the stack, including the status of provisioned switches and switches in version-mismatch mode.

            show switch stack-member-number

            Displays information about a specific member.

            show switch detail

            Displays detailed information about the stack.

            show switch neighbors

            Displays the stack neighbors.

            show switch stack-ports [summary]

            Displays port information for the stack.

            show redundancy

            Displays the redundant system and the current processor information. The redundant system information includes the system uptime, standby failures, switchover reason, hardware, configured and operating redundancy mode. The current processor information displayed includes the active location, the software state, the uptime in the current state and so on.

            show redundancy state

            Displays all the redundancy states of the active and standby switches.

            LACP Configuration: Example

            This example shows how to configure LACP and to verify creation of the LACP bundle and the status: 

            Switch(config)# !
interface TenGigabitEthernet1/0/1
 switchport mode trunk
 channel-group 1 mode active
 lacp port-priority 10
 ip dhcp snooping trust
!
interface TenGigabitEthernet1/0/2
 switchport mode trunk
 channel-group 1 mode active
 lacp port-priority 10
 ip dhcp snooping trust
!
interface TenGigabitEthernet1/0/3
 switchport mode trunk
 channel-group 1 mode active
 lacp port-priority 10
 ip dhcp snooping trust
!
interface TenGigabitEthernet1/0/4
 switchport mode trunk
 channel-group 1 mode active
 ip dhcp snooping trust
!
interface TenGigabitEthernet1/0/5
 switchport mode trunk
 channel-group 1 mode active
 ip dhcp snooping trust
!
interface TenGigabitEthernet1/0/6
 switchport mode trunk
 channel-group 1 mode active
 ip dhcp snooping trust
!
interface TenGigabitEthernet2/0/1
 switchport mode trunk
 channel-group 1 mode active
 lacp port-priority 10
 ip dhcp snooping trust
!
interface TenGigabitEthernet2/0/2
 switchport mode trunk
 channel-group 1 mode active
 lacp port-priority 10
 ip dhcp snooping trust
!
interface TenGigabitEthernet2/0/3
 switchport mode trunk
 channel-group 1 mode active
 lacp port-priority 10
 ip dhcp snooping trust
!
interface TenGigabitEthernet2/0/4
 switchport mode trunk
 channel-group 1 mode active
 ip dhcp snooping trust
!
interface TenGigabitEthernet2/0/5
 switchport mode trunk
 channel-group 1 mode active
 ip dhcp snooping trust
!
interface TenGigabitEthernet2/0/6
 switchport mode trunk
 channel-group 1 mode active
 ip dhcp snooping trust
!
interface Vlan1
 no ip address
 ip igmp version 1
 shutdown
!

Switch#  show etherchannel summary
		 
		Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port


Number of channel-groups in use: 1
Number of aggregators:           1

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
1      Po1(SU)         LACP      Te1/0/1(P)  Te1/0/2(P)  Te1/0/3(P)
                                 Te1/0/4(H)  Te1/0/5(H)  Te1/0/6(H)
                                 Te2/0/1(P)  Te2/0/2(P)  Te2/0/3(P)
                                 Te2/0/4(H)  Te2/0/5(H)  Te2/0/6(H)

            This example shows the switch backup interface pairs: 

            Switch# show interfaces switchport backup

Switch Backup Interface Pairs:

Active Interface        Backup Interface        State
------------------------------------------------------------------------
Port-channel1             Port-channel2             Active Standby/Backup Up

            This example shows the summary of the EtherChannel configured in the switch: 

            Switch# show ethernet summary

Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port


Number of channel-groups in use: 2
Number of aggregators:           2

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
1      Po1(SU)         LACP      Te1/0/1(P)  Te1/0/2(P)  Te1/0/3(P)
                                 Te1/0/4(P)  Te1/0/5(P)  Te1/0/6(P)
2      Po2(SU)         LACP      Te2/0/1(P)  Te2/0/2(P)  Te2/0/3(P)
                                 Te2/0/4(P)  Te2/0/5(P)  Te2/0/6(P)

            Flex Link Configuration: Example

            This example shows how to configure flex link and to verify creation and the status of the created link:

            Switch(config)# !
interface Port-channel1
 description Ports 1-6 connected to NW-55-SW
 switchport mode trunk
 switchport backup interface Po2
 switchport backup interface Po2 preemption mode forced
 switchport backup interface Po2 preemption delay 1
 ip dhcp snooping trust
!
interface Port-channel2
 description Ports 7-12connected to NW-55-SW
 switchport mode trunk
 ip dhcp snooping trust
!
interface GigabitEthernet0/0
 vrf forwarding Mgmt-vrf
 no ip address
 negotiation auto
!
interface TenGigabitEthernet1/0/1
 switchport mode trunk
 channel-group 1 mode on
 ip dhcp snooping trust
!
interface TenGigabitEthernet1/0/2
 switchport mode trunk
 channel-group 1 mode on
 ip dhcp snooping trust
!
interface TenGigabitEthernet1/0/3
 switchport mode trunk
 channel-group 1 mode on
 ip dhcp snooping trust
!
interface TenGigabitEthernet1/0/4
 switchport mode trunk
 channel-group 1 mode on
 ip dhcp snooping trust
!
interface TenGigabitEthernet1/0/5
 switchport mode trunk
 channel-group 1 mode on
 ip dhcp snooping trust
!
interface TenGigabitEthernet1/0/6
 switchport mode trunk
 channel-group 1 mode on
 ip dhcp snooping trust
!
interface TenGigabitEthernet2/0/1
 switchport mode trunk
 channel-group 2 mode on
 ip dhcp snooping trust
!
interface TenGigabitEthernet2/0/2
 switchport mode trunk
 channel-group 2 mode on
 ip dhcp snooping trust
!
interface TenGigabitEthernet2/0/3
 switchport mode trunk
 channel-group 2 mode on
 ip dhcp snooping trust
!
interface TenGigabitEthernet2/0/4
 switchport mode trunk
 channel-group 2 mode on
 ip dhcp snooping trust
!
interface TenGigabitEthernet2/0/5
 switchport mode trunk
 channel-group 2 mode on
 ip dhcp snooping trust
!
interface TenGigabitEthernet2/0/6
 switchport mode trunk
 channel-group 2 mode on
 ip dhcp snooping trust
!
interface Vlan1
 no ip address


		Switch#  show etherchannel summary
		 
		Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port


Number of channel-groups in use: 2
Number of aggregators:           2

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
1      Po1(SU)          -        Te1/0/1(P)  Te1/0/2(P)  Te1/0/3(P)
                                 Te1/0/4(P)  Te1/0/5(P)  Te1/0/6(P)
2      Po2(SU)          -        Te2/0/1(P)  Te2/0/2(P)  Te2/0/3(D)
                                 Te2/0/4(P)  Te2/0/5(P)  Te2/0/6(P)

            Viewing Redundancy Switchover History (GUI)

              Step 1   Click Monitor > Controller > Redundancy > States.

              The Redundancy States page is displayed. The values for the following parameters are displayed in the page:

              Parameter Description
              Index Displays the index number of the of the redundant unit.
              Previous Active Displays the Switches that was active before.
              Current Active Displays the Switches that is currently active.
              Switch Over Time Displays the system time when the switchover occurs.
              Switch Over Reason Displays the cause of the switchover.
              Step 2   Click Apply.

              Viewing Switchover States (GUI)

                Step 1   Click Monitor > Controller > Redundancy > States.

                The Redundancy States page is displayed. The values for the following parameters are displayed in the page:

                Parameter Description
                My State Shows the state of the active CPU Switch module. Values are as follows:
                • Active
                • Standby HOT
                • Disable
                Peer State Displays the state of the peer (or standby) CPU Switch module. Values are as follows:
                • Standby HOT
                • Disable
                Mode Displays the current state of the redundancy peer. Values are as follows:
                • Simplex— Single CPU switch module
                • Duplex— Two CPU switch modules
                Unit ID Displays the unit ID of the CPU switch module.
                Redundancy Mode (Operational) Displays the current operational redundancy mode supported on the unit.
                Redundancy Mode (Configured) Displays the current configured redundancy mode supported on the unit.
                Redundancy State Displays the current functioning redundancy state of the unit. Values are as follows:
                • SSP
                • Not Redundant
                Manual SWACT Displays whether manual switchovers have been enabled without the force option.
                Communications Displays whether communications are up or down between the two CPU Switch modules.
                Client Count Displays the number of redundancy subsystems that are registered as RF clients.
                Client Notification TMR Displays, in milliseconds, the time that an internal RF timer has for notifying RF client subsystems.
                Keep Alive TMR Displays, in milliseconds, the time interval the RF manager has for sending keep-alive messages to its peer on the standby CPU switch module.
                Keep Alive Count Displays the number of keep-alive messages sent without receiving a response from the standby CPU Switch module.
                Keep Alive Threshold Displays the threshold for declaring that interprocessor communications are down when keep-alive messages have been enabled (which is the default).
                RF Debug Mask Displays an internal mask used by the RF to keep track of which debug modes are on.
                Step 2   Click Apply.