Why AP’s use multiple IP addresses

A Mist AP will pull a management IP address from the Native VLAN.

By default, a Mist AP requests only one IP address i.e. from the Management VLAN (VLAN 1)

Features that would require multiple DHCP addresses:

Guest Portal

If a guest portal is configured using the Mist portal and the Guest SSID is a tagged VLAN, each AP will need to request an IP address on that tagged VLAN.

When the SSID is created the AP will do a DHCP DORA for the Guest VLAN

 

The AP requests the IP in order to create an SVI (Switch Virtual Interfaces) for the Guest VLAN on its eth0 interface, which is used for the redirection of the client to the Guest portal page.

 

Local Status Page

As documented in AP Settings

If the Local Status Page is configured for the Site – all the site AP’s will pull their own IP address from the Management VLAN, but also addresses for each of the VLANs configured on the AP.  This is at the site level so this needs to be taken into account when doing DHCP planning.