Multiple Destinations: Multicast addresses
Applies To: Windows 10, Windows 7, Windows 8, Windows 8.1, Windows Server 2008, Windows Server 2008 R2, Windows Server 2012, Windows Server 2012 R2, Windows Server Technical Preview, Windows Vista
Multicast addresses can be used to send messages to a set of nontransactional queues associated with a specific multicast address and to specify a set of response queues. A queue can be associated with a multicast address when the queue is created or later on by setting the PROPID_Q_MULTICAST_ADDRESS or MSMQQueueInfo.MulticastAddress property. A queue can be associated with only one multicast address. A queue that is associated with a multicast address can still receive messages over non-multicast transports.
A set of response queues associated with a specific multicast address can be specified in a message by setting the PROPID_M_RESP_FORMAT_NAME of MSMQMessage.ResponseDestination property to a multicast address format name.
Applications can request authentication by Message Queuing for messages sent to multicast addresses, but applications cannot send Message Queuing-encrypted or application-encrypted messages to multicast addresses.
Before sending a message to a multicast address, an application calls MQOpenQueue to open the set of associated destination queues with send access using a multicast address format name or sets the MSMQDestination.FormatName property of an MSMQDestination object using a multicast address format name. Messages sent to a multicast address are held in a multicast outgoing queue on the source computer before delivery. To deliver the copies of the message, Message Queuing establishes a session over TCP transport with each computer hosting a queue that is listening to the IP address and port specified in the multicast address format name used to send the message. The messages sent in these sessions consist of SRMP packets.
When authentication is requested, multicast messages are signed using an XML digital signature.
Note
Message Queuing cannot authenticate the sender of a multicast message by comparing the SID of the user who registered the certificate attached to the message with the sender identifier because the sender identifier is not conveyed in multicast messages.
For information on the digital signature used to sign multicast messages and other SRMP messages, see XML Digital Signatures.
The public queues associated with a specific multicast address can be located by specifying the multicast address in a criterion of a query. For more information, see Locating Queues.
For information on the format name used to send messages using multicast addresses, see Multicast Address Format Names.