A driver will use the connection string URI to make the initial connection to a mongod/mongos instance but will establish new connections once it detects that it is connected to a replica set or sharded cluster and the hostname used to connect doesn't match that used to define the replica set / sharded cluster.

The implication is that the driver needs to be able to resolve the 'internal' names used to define the mongo cluster, not just the hostname/ip provided in the original (client supplied) URI.

Recommend updating the following docs page to clarify that 'host1' is just a seed host and the driver will make additional connections based on the cluster configuration: http://docs.mongodb.org/manual/reference/connection-string/

Clarification could also be added to all the driver documentation pages.