Users Guide

Table Of Contents
Dell PowerConnect ArubaOS 5.0 | User Guide Remote Access Points | 169
Fallback Mode
The fallback mode (also known as backup configuration ) operates the remote AP if the master controller or the
configured primary and backup LMS are unreachable. The remote AP saves configuration information that allows
it to operate autonomously using one or more SSIDs in local bridging mode while supporting open association or
encryption with PSKs. You can also use the backup configuration if you experience network connectivity issues,
such as the WAN link or the central data center becomes unavailable. With the backup configuration, the remote
site does not go down if the WAN link fails or the data center is unavailable.
You define the backup configuration in the virtual AP profile on the controller. The remote AP checks for
configuration updates each time it establishes a connection with the controller. If the remote AP detects a
change, it downloads the configuration changes.
The following remote AP backup configuration options define when the SSID is advertised (refer to Table 37 for
more information):
z Always—Permanently enables the virtual AP. Recommended for bridge SSIDs.
z Backup—Enables the virtual AP if the remote AP cannot connect to the controller. This SSID is advertised
until the controller is reachable. Recommended for bridge SSIDs.
z Persistent—Permanently enables the virtual AP after the remote AP initially connects to the controller.
Recommended for 802.1x SSIDs.
z Standard—Enables the virtual AP when the remote AP connects to the controller. Recommended for 802.1x,
tunneled, and split-tunneled SSIDs. This is the default behavior.
While using the backup configuration, the remote AP periodically retries its IPSec tunnel to the controller. If you
configure the remote AP in backup mode, and a connection to the controller is re-established, the remote AP
stops using the backup configuration and immediately brings up the standard remote AP configuration. If you
configure the remote AP in always or persistent mode, the backup configuration remains active after the IPSec
tunnel to the controller has been re-established.
This section describes the following topics:
z “Configuring the fallback mode” on page169
z “Configuring the DHCP Server on the Remote AP” on page171
z “Advanced Backup Configuration Options” on page1733
Configuring the fallback mode
To configure the fallback mode, you must
z Configure the AAA profile.
z Configure the virtual AP profile
standard ESSID is up only when
there is connectivity
with the controller.
SSID configuration
obtained from the
controller.
Behaves like a classic
Dell branch office AP.
Provides a bridged
ESSID that is configured
from the controller and
stays up if there is
controller connectivity.
Split tunneling mode. Classic Dell thin AP
operation.
Decrypt tunnel mode
Table 37 Remote AP Modes of Operation and Behavior
Remote AP
Operation
Setting
Forward Mode Setting