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These two mobility controller switches can be grouped together in one mobility group to enable fast roaming
between clients of each respective subdomain.
Relevant configuration that needs to be done on the existing mobility controller switch is as given in the following:
wireless mobility group member ip 20.1.9.2 public-ip 20.1.9.2 group MG
wireless mobility group name MG
where MG is the mobility group name that is created, and 20.1.9.2 is the switch/wireless management IP address
of the new mobility controller added in the mobility group.
Configuration that needs to be done on the new mobility controller switch that was brought online is given in the
following:
wireless mobility controller
wireless mobility group member ip 20.1.3.2 public-ip 20.1.3.2 group MG
wireless mobility group name MG
wireless management interface Vlan605
wlan Predator 1 Predator
aaa-override
client vlan 702
security wpa wpa2 ciphers tkip
security dot1x authentication-list ise
no shutdown
ap cdp
where 20.1.3.2 is the switch/wireless management IP address of the existing mobility controller switch, MG is the
name of the mobility group that was created, VLAN605 is the wireless management interface on this mobility
controller switch, SSID named Predator is created, VLAN702 is the client VLAN for wireless endpoints on this
switch, authentication and encryption parameters are defined for this WLAN, and CDP is being enabled on all the
access points connecting to this switch.
This is a scalable method of deploying converged access with Cisco Catalyst 3850 Switches since each switch has
the capability to do 40 Gbps of wireless traffic termination. The preceding network can collectively terminate up to
320 Gbps of wireless traffic: 8 switches (4 in stack, and 4 acting as standalone). This sufficiently demonstrates the
capability of the Cisco Catalyst 3850 Switch to be future proofed for 802.11ac when that standard comes around.
Roaming in Cisco Unified Wireless Network Before roaming is explained in this section, it is essential to understand some terminologies that are used while
explaining roams in converged access deployment, starting with point of presence (PoP) and point of attachment
(PoA).
Point of presence (PoP) is defined as the point in the network where the wired infrastructure first sees the wireless
traffic. Packet conversions from 802.11 (wireless) to 802.3 (Ethernet) and vice versa take place at this point. PoP
serves several functionalities. It serves as a point for symmetrical routing and also serves where network security
policy is applied to the wireless traffic. In the Cisco Unified Wireless Network, the controller is where the PoP is
defined, since wireless traffic is terminated and converted to Ethernet frames at the controller, and it is at this point
that the wired infrastructure sees the frames from wireless endpoints.