Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

Machines in a cluster must have resolvable hostnames in DNS. Alternatively, 
you can use IP addresses instead, but you may not mix the two.

See 

. Cluster communication is 

normally initiated using the DNS hostnames of the machines.

A cluster must consist entirely of machines in the same series (X-Series and 
C-Series are compatible). 

For example, IronPort X1000, C60, C600, C30, C300, and C10 appliances 
can be in the same cluster; however, C60 and A60 appliances cannot be in the 
same cluster. If you attempt to add an incompatible appliance to an existing 
cluster, an error message explaining why that appliance cannot be added to 
the cluster will be displayed. 

A cluster must consist entirely of machines running the same version of 
AsyncOS. 

See 

 for how to upgrade 

members of a cluster.

Machines can either join the cluster via SSH (typically on port 22) or via the 
Cluster Communication Service (CCS). 

See 

. 

Once machines have joined the cluster, they can communicate via SSH or via 
Cluster Communication Service. The port used in configurable. SSH is 
typically enabled on port 22, and by default CCS is on port 2222, but you can 
configure either of these services on a different port. 

In addition to the normal firewall ports that must be opened for the appliance, 
clustered machines communicating via CCS must be able to connect with 
each other via the CCS port. See