As we saw in Chapter 1, Getting Started, to deploy site resilience across two datacenters with Exchange 2010, many namespaces were needed. They were as follows:
2x Internet Protocol namespaces (primary and standby datacenters)
2x OWA failback namespaces (primary and standby datacenters)
1x OWA failback namespace (standby datacenters)
1x Autodiscover namespace
2x RPC Client Access namespaces (primary and standby datacenters)
1x Legacy namespace (in case of a migration scenario)
Possibly a transport namespace for performing encryption with a partner organization
For example, in an active/passive datacenter scenario, one would typically have a namespace called mail.letsexchange.com for the active (primary) datacenter, and mail.standby.letsexchange.com for the passive (standby) datacenter, which would be used to provide services to users in case of a disaster with the active datacenter.
Besides the complexity involved in deploying and configuring so...