The most interesting entry can be found in ClusterXL Administration Guide R80.20 p.54:
Synchronizing Clusters on a Wide Area Network
Organizations sometimes need to locate Cluster Members in geographical locations that are distant from each other. A typical example is a replicated Data Center, whose locations are widely separated for disaster recovery purposes. In such a configuration, it is clearly impractical to use a cross cable for the synchronization network.
The synchronization network can be spread over remote sites, which makes it easier to deploy geographically distributed clustering. There are two limitations to this capability:
1. The synchronization network must guarantee no more than 100ms latency and no more than 5% packet loss.
2. The synchronization network may only include Layer 2 networking devices - switches and hubs. No Layer 3 routers are allowed on the synchronization network, because routers drop Cluster Control Protocol (CCP) packets.
You can monitor and troubleshoot geographically distributed clusters using the command line interface.
CCSP - CCSE / CCTE / CTPS / CCME / CCSM Elite / SMB Specialist