The Cisco centralized management feature (available via feature key) allows you to manage and
configure multiple appliances at the same time, reducing administration time and ensuring a consistent
configuration across your network. You do not need to purchase additional hardware for managing
multiple appliances. The centralized management feature provides increased reliability, flexibility, and
scalability within your network, allowing you to manage globally while complying with local policies.

A cluster is defined as a set of machines that share configuration information. Within the cluster,
machines (Cisco appliances) are divided into groups; every cluster will contain at least one group. A
given machine is a member of one and only one group. An administrator user can configure different
elements of the system on a cluster-wide, group-wide, or per-machine basis, enabling the segmentation
of Cisco appliances based on network, geography, business unit, or other logical relationships.

Clusters are implemented as a peer-to-peer architecture; there is no master/slave relationship within a
cluster. You may log into any machine to control and administer the cluster. (Some configuration
commands, however, are limited. See

Restricted Commands, page 35-15

The user database is shared across all machines in the cluster. That is, there will be only one set of users
and one administrator user (with the associated passwords) for an entire cluster. All machines that join
a cluster will share a single administrator password which is referred to as the admin password of the
cluster.