When using a route to listen to UDP multicast address , no messages seem to get consumed. No exceptions are observed.
Multicast address is defined as addresses in the range of 18.104.22.168 through 22.214.171.124 (http://en.wikipedia.org/wiki/Multicast_address)
Input was simple string (e.g. "Test String")
Found an old topic in the user discussion forum that seems related. Did not find any unit tests in the Camel source code exercising this behavior. (http://camel.465427.n5.nabble.com/camel-netty-and-multicast-tt4638622.html)