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: 192.168.300.0/24

WLC1 Primary:
==============

(WLC-Primary) >show interface summary

Number of Interfaces…………………….. 6

Interface Port Vlan Id IP Address Type Ap Mgr Guest
Name
——————————– —- ——–
management 1 100 192.168.100.5

(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
Interface Port Vlan Id IP Address Ap Mgr Guest
Name
Number of Interfaces…………………….. 6
——————————– —- ——–
management 1 200 192.168.200.5 Static Yes 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:27:20Redundancy
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 RelayDevice 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 Gig1/0/20 150 R T AIR-CAP26 Gig 0.1
WLC-Primary Gig1/0/3 140 H AIR-CT550 Gig 0/0/1

AP-SWITCH1#show runn int gig 1/0/1
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
switchport trunk encapsulation dot1q
switchport mode trunk
end

AP-SWITCH1#show runn int gig 1/0/7
switchport access vlan 300
switchport mode access

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:

 

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.

Hope this post was helpful….

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