Managing Access Points and Clusters

The U.S. Robotics Professional Access Point shows current basic configuration settings for clustered access points (location, IP address, MAC address, status, and availability) and provides a way of navigating to the full configuration for specific APs if they are cluster members.

Standalone access points or those which are not members of this cluster do not show up in this listing. To configure standalone access points, you must discover (via Kickstart) or know the IP address of the access point and by using its IP address in a URL (http://IPAddressOfAccessPoint).


Note	The U.S. Robotics Professional Access Point is not designed for multiple, simultaneous configuration changes. If you have a network that includes multiple access points, and more than one administrator is logged on to the Administration Web pages and making changes to the configuration, all access points in the cluster will stay in synch but there is no guarantee that all configuration changes specified by multiple users will be applied.

Understanding Clustering

A key feature of the U.S. Robotics Professional Access Point is the ability to form a dynamic, configuration-aware group (called a cluster) with other U.S. Robotics Professional Access Points in a network in the same subnet. Access points can participate in a self-organizing cluster which makes it easier for you to deploy, administer, and secure your wireless network. The cluster provides a single point of administration and lets you view the deployment of access points as a single wireless network rather than a series of separate wireless devices.

What is a Cluster?

A cluster is a group of access points which are coordinated as a single group via U.S. Robotics Professional Access Point administration. You cannot create multiple clusters on a single wireless network (SSID). Only one cluster per wireless network is supported.

How Many APs Can a Cluster Support?

Up to eight access points are supported in a cluster at any one time. If a new AP is added to a network with a cluster that is already at full capacity, the new AP is added in stand-alone mode. Note that when the cluster is full, extra APs are added in stand-alone mode regardless of the configuration policy in effect for new access points.

What Kinds of APs Can Cluster Together?

A single U.S. Robotics Professional Access Point can form a cluster with itself (a "cluster of one") and with other U.S. Robotics Professional Access Points of the same model. In order to be members of the same cluster, access points must be:

Of the same radio configuration (all one-radio APs or all two-radio APs)

Of the same band configuration (all single-band APs or all dual-band APs)

On the same LAN

Having a mix of APs on the network does not adversely affect U.S. Robotics Professional Access Point clustering in any way. However, it is helpful to understand the clustering behavior for administration purposes:

Access points of the same model will form a cluster.

Access points of other brands will not join the cluster. These APs should be administered with their own associated Administration tools.

Which Settings are Shared as Part of the Cluster Configuration and Which Are Not?

Most configuration settings defined via the U.S. Robotics Professional Access Point Administration Web pages will be propagated to cluster members as a part of the cluster configuration.

Settings Shared in the Cluster Configuration

Network name (SSID)

Administrator password

Configuration policy

User accounts and authentication

Wireless interface settings

Guest Welcome screen settings

Network Time Protocol (NTP) settings

Radio settings

Only Mode, Channel, Fragmentation Threshold, RTS Threshold and Rate Sets are synchronized across the cluster. Beacon Interval, DTIM Period, Maximum Stations, and Transmit Power do not cluster.


Note	When Channel Planning is enabled, the radio Channel is not synched across the cluster. See Stopping/Starting Automatic Channel Assignment.

When Channel Planning is enabled, the radio Channel is not synched across the cluster. See Stopping/Starting Automatic Channel Assignment

Security settings

QoS queue parameters

MAC address filtering

Settings Not Shared by the Cluster

The few exceptions (settings not shared among clustered access points) are the following most of which, by nature, must be unique:

IP addresses

MAC addresses

Location descriptions

Load Balancing settings

WDS bridges

Ethernet (Wired) Settings, including enabling or disabling Guest access

Guest interface configuration

Settings that are not shared must be configured individually on the Administration pages for each access point. To get to the Administration pages for an access point that is a member of the current cluster, click on its IP Address link on the Cluster > Access Points page of the current AP.

Cluster Mode

When an access point is a cluster member, it is considered to be in cluster mode. You define whether you want new access points to join the cluster or not via the configuration policy you set in the Basic Settings. (See Set Configuration Policy for New Access Points.) You can re-set an access point in cluster mode to standalone mode. (See Removing an Access Point from the Cluster.)

Note	When the cluster is full (eight APs is the limit), extra APs are added in stand-alone mode regardless of the configuration policy in effect for new access points. See How Many APs Can a Cluster Support?.

Standalone Mode

The U.S. Robotics Professional Access Point can be configured in standalone mode. In standalone mode, an access point is not a member of the cluster and does not share the cluster configuration, but rather requires manual configuration that is not shared with other access points. (See Set Configuration Policy for New Access Points and Removing an Access Point from the Cluster.)

Standalone access points are not listed on the Cluster > Access Points tab in the Administration UIs of APs that are cluster members. You need to know the IP address for standalone access points in order to configure and manage it directly. (See Navigating to an AP by Using its IP Address in a URL.)

The Basic Settings tab for a standalone access point indicates only that the current mode is standalone and provides a button for adding the access point to a cluster (group). If you click on any of the Cluster tabs on the Administration pages for an access point in standalone mode, you will be redirected to the Basic Settings page because Cluster settings do not apply to standalone APs.

Note	When the cluster is full (eight APs is the limit), extra APs are added in stand-alone mode regardless of the configuration policy in effect for new access points. See How Many APs Can a Cluster Support?.

For purposes of ease-of-use, the clustering component is designed to let new devices join a cluster without strong authentication. However, communications is protected against casual eavesdropping using . The assumption is that the private wired network to which the devices are connected is secure.Auto-Synch of Cluster Configuration

If you are making changes to the AP configuration that require a relatively large amount of processing (such as adding several new users), you may encounter a synchronization progress bar after clicking "Update" on any of the Administration pages. The progress bar indicates that the system is busy performing an auto-synch of the updated configuration to all APs in the cluster. The Administration Web pages are not editable during the auto-synch.

Note that auto-synchronization always occurs during configuration updates that affect the cluster, but the processing time is usually negligible. The auto-synch progress bar is displayed only for longer-than-usual wait times.

Understanding Access Point Settings

The Access Points tab provides information about all access points in the cluster.

From this tab, you can view location descriptions, IP addresses, enable (activate) or disable (deactivate) clustered access points, and remove access points from the cluster. You can also modify the location description for an access point.

The IP address links provide a way to navigate to configuration settings and data on an access point.

Stand-alone access points (those which are not members of the cluster) are not shown on this page.

The following table describes the access point settings and information display in detail.


Field	Description
Location	Description of where the access point is physically located.
MAC Address	Media Access Control (MAC) address of the access point. A MAC address is a permanent, unique hardware address for any device that represents an interface to the network. The MAC address is assigned by the manufacturer. You cannot change the MAC address. It is provided here for informational purposes as a unique identifier for the access point. The address shown here is the MAC address for the bridge (`br0`). This is the address by which the AP is known externally to other networks. To see MAC addresses for Guest and Internal interfaces on the AP, see the Status > Interfaces tab.
IP Address	Specifies the IP address for the access point. Each IP address is a link to the Administration Web pages for that access point. You can use the links to navigate to the Administration Web pages for a specific access point. This is useful for viewing data on a specific access point to make sure a cluster member is picking up cluster configuration changes, to configure advanced settings on a particular access point, or to switch a standalone access point to cluster mode.

Modifying the Location Description

Navigate to the Basic Settings tab.

Update the Location description in section 1 under "Review Description of this Access Point."

Click Update button to apply the changes.

Removing an Access Point from the Cluster

Click the checkbox next to the access point so that the box is checked.

Click Remove from Cluster.

The change will be reflected under Status for that access point; the access point will now show as standalone (instead of cluster).


Note	In some situations it is possible for the cluster to become out of sync. If after removing an access point from the cluster, the AP list still reflects the deleted AP or shows an incomplete display; refer to the information on Cluster Recovery in Appendix B: Troubleshooting in the Administrators Guide.

Adding an Access Point to a Cluster

To add an access point that is currently in standalone mode back into a cluster, do the following.

Go to the Administration Web pages for the standalone access point. (See Navigating to an AP by Using its IP Address in a URL.)

The Administration Web pages for the standalone access point are displayed.

Click the Basic Settings tab in the Administration pages for the standalone access point.

The Basic Settings tab for a standalone access point indicates that the current mode is standalone and provides a button for adding the access point to a cluster (group).


Note	If you click on any of the Cluster tabs on the Administration pages for an access point in standalone mode, you will be redirected to the Basic Settings page because Cluster settings do not apply to stand-alone APs.

Click the Join Cluster button.

The access point is now a cluster member. Its Status (Mode) on the Cluster > Access Points tab now indicates "cluster" instead of "standalone".


Note	In some situations it is possible for the cluster to become out of sync. If after removing an access point from the cluster, the AP list still reflects the deleted AP or shows an incomplete display; refer to the information on Cluster Recovery in Appendix B: Troubleshooting in the Administrators Guide.

Navigating to Configuration Information for a Specific AP and Managing Standalone APs

In general, the U.S. Robotics Professional Access Point is designed for central management of clustered access points. For access points in a cluster, all access points in the cluster reflect the same configuration. In this case, it does not matter which access point you actually connect to for administration.

There may be situations, however, when you want to view or manage information on a particular access point. For example, you might want to check status information such as client associations or events for an access point. Or you might want to configure and manage features on an access point that is running in standalone mode. In these cases, you can navigate to the Administration Web interface for individual access points by clicking the IP address links on the Access Points tab.

All clustered access points are shown on the Cluster > Access Points page. To navigate to clustered access points, you can simply click on the IP address for a specific cluster member shown in the list.

Navigating to an AP by Using its IP Address in a URL

You can also link to the Administration Web pages of a specific access point, by entering the IP address for that access point as a URL directly into a Web browser address bar in the following form:

where IPAddressOfAccessPoint is the address of the particular access point you want to monitor or configure.

For standalone access points, this is the only way to navigate to their configuration information.

If you do not know the IP address for a standalone access point, use Kickstart to find all APs on the network and you should be able to derive which ones are standalone by comparing KickStart findings with access points listed on the Cluster > Access Points tab. The APs that Kickstart finds that are not shown on the this tab are probably standalone APs.