Cisco Cisco Expressway Maintenance Manual
About clusters
An Expressway can be part of a cluster of up to six Expressways. Each Expressway in the cluster is a peer
of every other Expressway in the cluster. When creating a cluster, you define a cluster name and nominate
one peer as the master from which all relevant configuration is replicated to the other peers in the cluster.
Clusters are used to:
of every other Expressway in the cluster. When creating a cluster, you define a cluster name and nominate
one peer as the master from which all relevant configuration is replicated to the other peers in the cluster.
Clusters are used to:
n
Increase the capacity of your Expressway deployment compared with a single Expressway.
n
Provide redundancy in the rare case that an Expressway becomes inaccessible (for example, due to a
network or power outage) or while it is in
network or power outage) or while it is in
(for example, during a software upgrade).
About the configuration master
All peers in a cluster must have identical configuration for subzones, zones, links, pipes, authentication,
bandwidth control and Call Policy. To achieve this, you define a cluster name and nominate one peer as the
configuration master. Any configuration changes made to the master peer are then automatically replicated
across all the other peers in the cluster.
bandwidth control and Call Policy. To achieve this, you define a cluster name and nominate one peer as the
configuration master. Any configuration changes made to the master peer are then automatically replicated
across all the other peers in the cluster.
You should only make configuration changes on the master Expressway. Any changes made on other peers
are not reflected across the cluster, and will be overwritten the next time the master’s configuration is
replicated across the peers. The only exceptions to this are some
are not reflected across the cluster, and will be overwritten the next time the master’s configuration is
replicated across the peers. The only exceptions to this are some
You may need to wait up to one minute before changes are updated across all peers in the cluster.
Secure communication between peers
The Expressway uses IPsec (Internet Protocol Security) to enable secure communication between each
cluster peer. Authentication is carried out through the use of a pre-shared access key.
cluster peer. Authentication is carried out through the use of a pre-shared access key.
Each peer in the cluster must be individually configured with the IP address and associated access key of
every other peer in that cluster.
every other peer in that cluster.
Cisco Expressway Administrator Guide (X8.5)
Page 134 of 394
Clustering and peers
About clusters