MSM7xx Controllers Configuration Guide v6.4.0

4. The AP is now managed by the controller, and it can be configured and monitored using the
controller management tool.
NOTE:
• APs must be connected to the network via Port 1 (or the Uplink port on an HP 517 or
MSM317) for discovery to work.
• Unprovisioned APs must obtain an IP address from a DHCP server before discovery can
be initiated. When discovery occurs on a VLAN, the DHCP server must be active on the
VLAN.
Discovery is performed whenever an AP:
• Is restarted (or reset to factory defaults)
• Loses connectivity with its controller
• Is removed and rediscovered using an action on the Controlled APs >> Overview > Discovered
APs page.
Discovery methods
Four discovery methods are available. The following table summaries their features and
recommended applications.
Suggested useSupported byDescriptionMethod
Both the controller and AP
reside on the same subnet.
Unprovisioned APsAP issues UDP broadcasts to
discover controllers on the
same subnet.
UDP broadcast
The AP is on a different
subnet than the controller.
Unprovisioned APsAP obtains controller
address from a specially
configured DHCP server.
DHCP
The AP is on a different
subnet than the controller.
Unprovisioned APs
Provisioned APs
AP obtains controller
address from a DNS server
using predefined host
names.
DNS
DHCP and DNS are not
used and the AP is on a
Provisioned APsAP connects to a specific
controller using a list of
Specific IP addresses
different subnet than the
controller.
pre-configured static IP
addresses.
NOTE: A controller listens for discovery requests on the interfaces configured on the Controller
>> Management > Device Discovery page. (See “Discovery priority” (page 152)).
UDP broadcast discovery
The AP sends a UDP broadcast to discover all controllers that are on the same subnet as the AP.
DHCP discovery
When configured as DHCP client (which is the factory default setting for all APs), an AP can obtain
the IP addresses of controllers on the network from any DHCP server configured to support the
Colubris Vendor Class (DHCP option 43).
Vendor Class enables an administrator to define a list of up to five available controllers on the
network to which APs can connect.
• If the controller is configured to operate as the DHCP server for the network, you can define
the list of available controllers by selecting Controller >> Network > Address allocation > DHCP
server and then configure the Controller discovery option.
Discovery of controllers by controlled APs 149