Cisco Cisco Expressway Maintenance Manual
Maintaining a cluster
The
Clustering
page (
System > Clustering
) lists the IP addresses of all the peers in the cluster, to which
this Expressway belongs, and identifies the master peer.
Cluster name
The Cluster name is used to identify one cluster of Expressways from another. Set it to the fully qualified
domain name (FQDN) used in SRV records that address this Expressway cluster, for example
cluster1.example.com
domain name (FQDN) used in SRV records that address this Expressway cluster, for example
cluster1.example.com
.
The FQDN can comprise multiple levels. Each level's name can only contain letters, digits and hyphens,
with each level separated by a period (dot). A level name cannot start or end with a hyphen, and the final level
name must start with a letter.
with each level separated by a period (dot). A level name cannot start or end with a hyphen, and the final level
name must start with a letter.
Cluster pre-shared key
The Expressway uses IPsec (Internet Protocol Security) to enable secure communication between each
cluster peer.
cluster peer.
The Cluster pre-shared key is the common IPsec access key used by each peer to access every other peer
in the cluster.
in the cluster.
Note: each peer in the cluster must be configured with the same Cluster pre-shared key.
Setting configuration for 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.
Adding and removing peers from a cluster
After a cluster has been set up you can add new peers to the cluster or remove peers from it.
Note that:
n
Systems that are configured as peers must not also be configured as neighbors to each other, and vice
versa.
versa.
n
If peers are deployed on different LANs, there must be sufficient connectivity between the networks to
ensure a low degree of latency between the peers - a maximum delay of 15ms one way, 30ms round-trip.
ensure a low degree of latency between the peers - a maximum delay of 15ms one way, 30ms round-trip.
n
Cluster peers can be in separate subnets. Peers communicate with each other using H.323 messaging,
which can be transmitted across subnet boundaries.
which can be transmitted across subnet boundaries.
n
Deploying all peers in a cluster on the same LAN means they can be configured with the same routing
information such as local domain names and local domain subnet masks.
information such as local domain names and local domain subnet masks.
Changing the master peer
You should only need to change the Configuration master when:
n
the original master peer fails
n
you want to take the master Expressway unit out of service
Cisco Expressway Administrator Guide (X8.1)
Page 100 of 344
Clustering and peers
Managing clusters and peers