Multicast Discovery with non-default group name not working

Hi all,

I am using .Net version api (NMS) to discover a broker, the discoveryUrl in
transportConnector of activemq.xml is "multicast://224.0.0.10:17500". And I
used the same url in client code and it works.

However, if i want to change to non-default group like
"multicast://224.0.0.10:17500?group=hello", I can capture UDP package from
network and ActiveMq is broadcasting right info, some info from UDP package:
".....*hello*.ActiveMQ-4.alive.%localhost%tcp://machine_name:61616".

My client code is changed to like this:

using Apache.NMS;
using Apache.NMS.Util;

var brokerUrl =
"activemq.discovery:(multicast://224.0.0.10:17500?group=hello)";
var connectionFactory = new NMSConnectionFactory(brokerUrl);
var connection = connectionFactory.CreateConnection();
var session = connection.CreateSession(); <== Execution hangs here!

My application hangs on the last line. If using the default group name
(without setting '?group=hello'), it works fine. My environment is
1. ActiveMq server : 5.10.0
2. Apache.NMS.ActiveMQ.dll: 1.6.2
3. Apache.NMS.dll: 1.6.0
4. Code is compiled in VS2013, against .Net 4 framework.

Has anyone encourntered same issue?

Thanks in advance.

Regards,
Milo