How Aps Discover Zonedirector On The Network - Ruckus Wireless ZoneDirector 1100 User Manual

How APs Discover ZoneDirector on the Network

1. When an AP starts up, it sends out a DHCP discovery packet to obtain an IP address.
2. The DHCP server responds to the AP with the allocated IP address. If you configured DHCP
Option 43 (see "Option 2: Customize Your DHCP Server"
response will also include (among others) the IP addresses of ZoneDirector devices on the
network along with the address of the DNS server that can help resolve the ZoneDirector
IP addresses.
3. After the AP obtains an IP address, it first attempts to contact a ZoneDirector whose IP
address has been pre-configured on the AP. If an AP has a pre-configured ZoneDirector IP
address, it will always use an L3 LWAPP (lightweight access point protocol) discovery
message to attempt to discover the pre-configured primary/secondary ZoneDirector.
• An AP with a pre-configured ZoneDirector IP address will only attempt to discover the
pre-configured ZoneDirector(s) and will skip the DHCP/DNS/last joined ZoneDirector
steps. If it is unable to contact its pre-configured ZoneDirector, it will enter "sulk" state,
and will remain in an idle/discover/sulk loop until it receives a response from a pre-
configured primary or secondary ZoneDirector.
4. If a primary/secondary ZoneDirector IP address has not been configured on the AP, the AP
next attempts to build a list of candidate ZoneDirectors by sending an L3 discovery request
(IPv4 subnet broadcast/IPv6 multicast packet) to each candidate address received from
DHCP and DNS at the same time, and waits for a response from any ZoneDirector that can
respond.
• The AP may receive multiple responses from DHCP and DNS if multiple ZoneDirector
IP addresses have been configured on the DHCP server or DNS server.
5. If the AP receives a response from a single ZoneDirector device, it will attempt to register
with that ZoneDirector device.
6. If the AP receives responses from multiple ZoneDirector devices, it will attempt to register
with the ZoneDirector that it previously registered with (if any).
• This ZoneDirector can be on the same local IP subnet or a different subnet. The AP will
have a preference for a ZoneDirector device that it previously registered with (over a
locally connected ZoneDirector).
7. If this is the first time that the AP is registering with ZoneDirector, it will attempt to register
with the ZoneDirector device that has the lowest AP load. The AP computes the load by
subtracting the current number of APs registered with ZoneDirector from the maximum
number of APs that ZoneDirector is licensed to support.
If the AP does not receive a response from any ZoneDirector device on the network, it goes
into idle mode. After a short period of time, the AP will attempt to discover ZoneDirector again
by repeating the same discovery cycle. The AP will continue to repeat this cycle until it
successfully registers with a ZoneDirector.
Introducing Ruckus Wireless ZoneDirector
Ensuring That APs Can Communicate with ZoneDirector
on page 14), the DHCP offer
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