How to assign an AP to register to a specific ZoneDirector?
SummaryThis article discusses various methods to register an AP with the ZoneDirector.
QuestionHow to assign an AP to register to a specific ZoneDirector?
Customer EnvironmentZoneDirector managed APs
Root CauseAP couldn't join the ZD since it is on a separate subnet.
ResolutionThere are several different ways to make sure an Access Point connects to a specific ZoneDirector. The key point is that the Access Point discovers and requests to join a ZoneDirector, so the methods depend on the design of your network and controlling the ZoneDirector discovery protocols.
If the Access Points are in the same subnet, they will do a Layer 2 LWAPP discovery, and automatically find all ZoneDirectors in the same subnet. The ZoneDirector has an auto allow feature that when enabled will automatically respond back to the Access Point with the number of open licenses for AP’s that are available. If multiple ZoneDirectors are on the same subnet with auto allow (configured on the Configure --> Access Point page) respond, the Access Point will choose to join the ZoneDirector with the most available leases. This system will balance the AP’s across the ZoneDirectors. If you want to specify which Access Point goes to which ZoneDirector, you can disable “auto-allow” and manually allow the Access Points one by one in the ZoneDirector Monitor Access Point Screen. If an Access Point has joined a ZoneDirector and you no longer want it controlled by that ZoneDirector, you can connect to the Access Points GUI directly (browse to the AP IP address, login is the same as the controlling ZoneDirector) and reset it to factory defaults. Alternately, you can also login to the AP using a SSH session and run "set factory" command followed by the "reboot" command. Then you must delete the AP configuration from the ZoneDirector before the AP reboots.
You can manually configure each Access Point with a static primary and secondary ZoneDirector IP using the AP CLI command: set director ip primaryip secondaryip . This disables the layer 2 LWAPP discovery and forces the AP to first the primary, and if listed to the secondary if the primary is not available. If you have enough licenses on each ZoneDirector you could use this to set up some AP to one ZD, some to the other as primary, flipping the secondary’s as redundant.
For Access Points connected to the ZoneDirector via Layer 3, or from other subnets, there are four methods of provisioning the Access Point for Layer 3 discovery and connectivity. The simplest method is to first connect the Access Points to the ZoneDirector via Layer 2, so that they learn the ZoneDirector's IP address. They can join via auto-allow or manual allow as set up above. Starting in version 8.1 you can also define a primary and secondary ZoneDirector to be provisioned into an Access Point once it joins and gets provisioned. But if you are manually load sharing between ZD’s, this feature will not work as once an Access Point connects to a secondary ZoneDirector, it will learn the new settings from that ZoneDirector which if now set as the primary in this configuration it will stick with this until it becomes unavailable. This will end up with all Access Points on one ZoneDirector until it becomes unavailable. The second automatic way to teach an Access Point how to discover the ZoneDirector is by configuring the DHCP server that provides management IP addresses to the Access Points with DHCP option 43, this teaches the Access point a primary and optionally a secondary IP address. You can use this to set all Access Points in a given Subnet to the same primary ZoneDirector, and have access to a redundant ZoneDirector if available with enough licenses. The last automatic method is to use DNS, which also requires the AP to get an IP from DHCP which includes the local domain name. The AP will then do a DNS lookup for zonedirector.localdomain.lan
Finally, for Layer 3 operation, manually configuring each AP with the correct ZD address using the CLI is the only way to configure an AP already installed in a different subnet, and once configured manually, disables the automatic methods above including Layer 2 LWAPP discovery. This is the surest way to direct Access Points to a specific ZoneDirector.