Users Guide

Dell PowerConnect ArubaOS 5.0 | User Guide Remote Access Points | 177
or
ap-name <name>
virtual-ap <name>
ap-system-profile <name>
DNS Controller Setting
In addition to specifying IP addresses for controllers, you can also specify the master DNS name for the controller
when provisioning the remote AP. The name must be resolved to an IP address when attempting to setup the
IPSec tunnel. For information on how to configure a host name entry on the DNS server, refer to the vendor
documentation for your server. Dell recommends using a maximum of 8 IP addresses to resolve a controller name.
If the remote AP gets multiple IP addresses responding to a host name lookup, the remote AP can use one of
them to establish a connection to the controller. For more detailed information, see the next section “Backup
Controller List” on page177.
Specifying the name also lets you move or change remote AP concentrators without reprovisioning your APs. For
example, in a DNS load-balancing model, the host name resolves to a different IP address depending on the
location of the user. This allows the remote AP to contact the controller to which it is geographically closest.
The DNS setting is part of provisioning the AP. The easiest way to provision an AP is to use the Provisioning page
in the WebUI. These instructions assume you are only modifying the controller information in the Master
Discovery section of the Provision page.
Specify the DNS name using the WebUI
1. Navigate to the Configuration > Wireless > AP Installation > Provisioning page. Select the remote AP and
click Provision.
2. Under Master Discovery enter the master DNS name of the controller.
3. Click Apply and Reboot.
For more information, see “Provision the AP” on page161.
Backup Controller List
Using DNS, the remote AP receives multiple IP addresses in response to a host name lookup. Known as the
backup controller list, remote APs go through this list to associate with a controller. If the primary controller is
unavailable or does not respond, the remote AP continues through the list until it finds an available controller.
This provides redundancy and failover protection.
If the remote AP loses connectivity on the IPSec tunnel to the controller, the remote AP establishes connectivity
with a backup controller from the list and automatically reboots. Network connectivity is lost during this time. As
described in the section “Remote AP Failback” on page178, you can also configure a remote AP to revert back to
the primary controller when it becomes available.To complete this scenario, you must also configure the LMS IP
address and the backup LMS IP address.
For example, assume you have two data centers, data center 1 and data center 2, and each data center has one
master controller in the DMZ. You can provision the remote APs to use the controller in data center 1 as the
primary controller, and the controller in data center 2 as the backup controller. If the remote AP loses
connectivity to the primary, it will attempt to establish connectivity to the backup. You define the LMS
parameters in the AP system profile.
Note: Reprovisioning the AP causes it to automatically reboot.