Alcatel-Lucent omniaccess User Manual

C

HAPTER

 4

This chapter outlines the steps required to configure the various 
redundancy options available in an Alcatel network. The 
redundancy can include backing up an Alcatel Mobility Controller 
for the Access Points being controlled (and through them the 
clients accessing the wireless network), backing up an Alcatel 
Master switch.

The underlying mechanism for the redundancy solutions in the 
Alcatel solution is the standard redundancy protocol, Virtual 
Router Redundancy Protocol (VRRP). This mechanism can be 
used to create various redundancy solutions, including pairs of 
local switches acting in an active-active mode or a hot-standby 
mode, master backing up a set of local switches, a pair of 
switches acting as a redundant pair of master switches in a hot 
standby mode. Each of these modes is explained in greater detail 
with the required configuration.

VRRP is a protocol that is designed to eliminate the single point of 
failure by providing an election mechanism amongst n switches 
to elect a “master” switch. This master switch is the owner of the 
configured Virtual IP address for this VRRP instance. When the 
master becomes unavailable, one of the backup switches takes 
the place of the master, thereby getting ownership of the Virtual 
IP address. All the network elements (such as the Access Points 
and other switches in this case) can be configured to access the 
Virtual IP, thereby providing a transparent redundant solution to 
the rest of the network.