Cisco Wireless HA N+1 configuration (Lab Testing)

With software release 7.4 and above Cisco has introduced the N+1 HA feature set within the Cisco Unified Wireless Network (CUWN) framework which allows a single WLC to be used as a backup WLC for N primary controllers.

Following is the configuration/documentation guide:

http://www.cisco.com/c/en/us/td/docs/wireless/technology/hi_avail/N1_High_Availability_Deployment_Guide/Introduction.html

The N+1 HA architecture provides redundancy for controllers across geographically separate data centers with low cost of deployment. Lately I had been working in couple of scenarios and had been not been sure if this is supposed to work over L3 network and so did a small Lab to test the same.

My network setup:

WLC1 (vlan 100)------------L3 Switch -----------------WLC2(vlan200)

                                              |

                                              |

                                              |

                                      APs (vlan 300)

Vlan 100: 192.168.100.0/24

Vlan 200: 192.168.200.0/24

Vlan 300: 192.168.30.0/24

WLC1 Primary:

(WLC-Primary) >show interface summary

 Number of Interfaces.......................... 6

Interface Name                   Port Vlan Id  IP Address      Type    Ap Mgr Guest

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

management                       1    100      192.168.100.5   Static  Yes    No

redundancy-management            1    100      192.168.100.10  Static  No     No

redundancy-port                  -    untagged 169.254.100.10  Static  No     No

printer-vlan                     1    99       10.10.99.100    Dynamic No     No

service-port                     N/A  N/A      0.0.0.0         Static  No     No

(WLC-Primary) >show redundancy summary

Redundancy Mode = SSO DISABLED

     Local State = ACTIVE

      Peer State = N/A

            Unit = Primary

         Unit ID = 50:3D:E5:1A:27:20

Redundancy State = N/A

    Mobility MAC = 50:3D:E5:1A:27:20

Redundancy Management IP Address................. 192.168.100.10

Peer Redundancy Management IP Address............ 192.168.100.11

Redundancy Port IP Address....................... 169.254.100.10

Peer Redundancy Port IP Address.................. 169.254.100.11

(WLC-Primary) >show advanced backup-controller

  

AP primary Backup Controller .................... WLC-Secondary 192.168.200.5

AP secondary Backup Controller ..................

WLC2 Secondary:

(WLC-Secondary) >show interface summary

 Number of Interfaces.......................... 6

Interface Name                   Port Vlan Id  IP Address      Type    Ap Mgr Guest

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

management                       1    200      192.168.200.5   Static  Yes    No

redundancy-management            1    200      192.168.200.10  Static  No     No

redundancy-port                  -    untagged 169.254.200.10  Static  No     No

printer-vlan                     1    99       10.10.99.100    Dynamic No     No

service-port                     N/A  N/A      0.0.0.0         Static  No     No

virtual                          N/A  N/A      1.1.1.1         Static  No     No

(WLC-Secondary) >show redundancy summary

Redundancy Mode = SSO DISABLED

     Local State = ACTIVE

      Peer State = N/A

            Unit = Secondary - HA SKU

         Unit ID = E0:5F:B9:46:99:00

Redundancy State = N/A

    Mobility MAC = 50:3D:E5:1A:27:20

Redundancy Management IP Address................. 192.168.200.10

Peer Redundancy Management IP Address............ 192.168.200.11

Redundancy Port IP Address....................... 169.254.200.10

Peer Redundancy Port IP Address.................. 169.254.200.11

(WLC-Secondary) >show advanced backup-controller

 AP primary Backup Controller ....................  0.0.0.0

AP secondary Backup Controller ..................

L3 Switch:

AP-SWITCH1#show cdp neighbors

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

                  S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone,

                  D - Remote, C - CVTA, M - Two-port Mac Relay

Device ID        Local Intrfce     Holdtme    Capability  Platform  Port ID

WLC-Secondary    Gig 1/0/1         152               H    AIR-CT550 Gig 0/0/1

TEST-AP-2        Gig 1/0/7         142              R T   AIR-LAP12 Gig 0.1

TEST-AP-1        Gig 1/0/20        150              R T   AIR-CAP26 Gig 0.1

WLC-Primary      Gig 1/0/3         140               H    AIR-CT550 Gig 0/0/1

AP-SWITCH1#show runn int gig 1/0/1

Building configuration...

Current configuration : 127 bytes

!

interface GigabitEthernet1/0/1

switchport access vlan 100

switchport trunk encapsulation dot1q

switchport mode trunk

end

AP-SWITCH1#show runn int gig 1/0/3

Building configuration...

Current configuration : 99 bytes

!

interface GigabitEthernet1/0/3

switchport trunk encapsulation dot1q

switchport mode trunk

end

AP-SWITCH1#show runn int gig 1/0/7

Building configuration...

Current configuration : 90 bytes

!

interface GigabitEthernet1/0/7

switchport access vlan 300

switchport mode access

end

Testing:

========

APs configured with dhcp option 43 to join the Primary WLC (192.168.100.5).

Once the APs join the Primary WLC , under high availability configured the Primary and the Secondary WLCs.

Make sure you have configured the secondary WLC (HA-SKU) on the other L3 network as Backup Primary Controller:

In our setup both the APs were on the Primary WLC initially:

Once the connectivity to the Primary WLC is lost (We shut down the port to the Primary-WLC on the Switch). We find the APs automatically falling back to the Secondary.

AP-SWITCH1(config)#int gig 1/0/3

AP-SWITCH1(config-if)#shut

AP-SWITCH1(config-if)#

1w1d: %LINK-5-CHANGED: Interface GigabitEthernet1/0/3, changed state to administratively down

1w1d: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/3, changed state to down

Licensing:

http://www.cisco.com/c/en/us/td/docs/wireless/technology/hi_avail/N1_High_Availability_Deployment_Guide/N1_HA_Overview.html

HA-SKU as Secondary Controller

With Release 7.4, an HA-SKU controller can be used as a secondary controller. In this example, the secondary controller is running a 50 AP permanent license and is configured to be an HA-SKU controller. Therefore it has a maximum AP capacity of 500.