6.0 JDBC driver cannot connect to 5.1.5 server, front end protocol error

Question:
We are trying to upgrade our drivers to 6.0, while having most of databases on 5.1.5. Attempt to connect from JDBC 6.0 to 5.1.5 produces error. Is this expected behavior? vsql 6.0 connect to 5.1.5 just fine.

Output from 5.0 Drivers:
Vertica Database v5.1.5-0 Vertica JDBC Driver Vertica JDBC Driver 4.1.17

Output from 5.1 Drivers:
Vertica Database 05.01.0005 vertica.jar 05.01.0005

Output from 6.0 Drivers:
An error occurred while establishing the connection:
Long Message: [Vertica][VJDBC](100081) FATAL: unsupported frontend protocol 3.3: server supports 3.0 to 3.2

Details:
Type: java.sql.SQLException    Error Code: 100081    SQL State: HY000

Solution:
Per the docs (Programmers Guide, Client Driver and Server Version Compatibility page - http://my.vertica.com/docs/6.0.0/HTML/index.htm#16472.htm) the 6.0 drivers are only compatible with version 6.0 server. The older drivers are forward compatible but the newer are not backward compatible.Anytime you see the "unsupported front end protocol" error it's an indication of a mismatch between driver and server.