Interface groups are logical groups of interfaces. Interface
groups facilitate user configuration where the same interface group can be
configured on multiple WLANs or while overriding a WLAN interface per AP group.
An interface group can exclusively contain either quarantine or nonquarantine
interfaces. An interface can be part of multiple interface groups.
A WLAN can be associated with
an interface or interface group. The interface group name and the interface
name cannot be the same.
This feature also enables you
to associate a client to specific subnets based on the foreign controller that
they are connected to. The anchor controller WLAN can be configured to maintain
a mapping between foreign controller MAC and a specific interface or interface
group (Foreign maps) as needed. If this mapping is not configured, clients on
that foreign controller gets VLANs associated in a round robin fashion from
interface group configured on WLAN.
Controller marks VLAN as dirty when the clients are unable to receive IP
address using DHCP. The VLAN interface is marked as dirty based on two methods:
Aggressive Method—When only one failure is counted per association per
client and controller marks VLAN as dirty interface when a failure occurs three
times for a client or for three different clients.
Non-Aggressive Method—When only one failure is counted per association
per client and controller marks VLAN as a dirty interface only when three or
more clients fail.