5/26/05 Cisco Wireless LAN Controller Automatic Time Setting
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•If the Cisco 1000 Series lightweight access point finds no Master Cisco Wireless LAN Controller
on the same subnet, it attempts to contact stored Mobility Group members by IP address.
•Should none of the Mobility Group members be available, and if the Cisco 1000 Series light-
weight access point has no Primary, Secondary, and Tertiary Cisco Wireless LAN Controllers
assigned and there is no Master Cisco Wireless LAN Controller active, it attempts to associate
with the least-loaded Cisco Wireless LAN Controller on the same subnet to respond to its
discovery messages with unused ports.
This means that when sufficient Cisco Wireless LAN Controllers are deployed, should one Cisco Wireless
LAN Controller fail, active Cisco 1000 Series lightweight access point client sessions are momentarily
dropped while the dropped Cisco 1000 Series lightweight access point associates with an unused port
on another Cisco Wireless LAN Controller, allowing the client device to immediately reassociate and
reauthenticate.
Cisco Wireless LAN Controller Automatic Time SettingCisco Wireless LAN Controller Automatic Time Setting
Each Cisco Wireless LAN Controller can have its time manually set or can be configured to obtain the
current time from one or more Network Time Protocol (NTP) servers. Each NTP server IP address is
added to the Cisco Wireless LAN Controller database. Each Cisco Wireless LAN Controller searches for
an NTP server and obtains the current time upon reboot and at each user-defined polling interval (daily
to weekly).
Cisco Wireless LAN Controller Time ZonesCisco Wireless LAN Controller Time Zones
Each Cisco Wireless LAN Controller can have its time zone manually set or can be configured to obtain
the current time from one or more Network Time Protocol (NTP) servers. Each NTP server IP address is
added to the Cisco Wireless LAN Controller database. Each Cisco Wireless LAN Controller can search for
an NTP server and obtain the current time zone upon reboot and at each user-defined (daily to weekly)
polling interval.
Network Connections to Cisco Wireless LAN ControllersNetwork Connections to Cisco Wireless LAN Controllers
Regardless of operating mode, all Cisco Wireless LAN Controllers use the network as an 802.11 Distri-
bution System. Regardless of the Ethernet port type or speed, each Cisco Wireless LAN Controller
monitors and communicates with its related Cisco Wireless LAN Controllers across the network. The
following sections give details of these network connections:
•Cisco 2000 Series Wireless LAN Controllers
•Cisco 4100 Series Wireless LAN Controllers
•Cisco 4400 Series Wireless LAN Controllers