Troubleshooting multicast communication with MulticastNetworkTest.exe

OVERVIEW:

EPM can be configured to use multicast in many different ways.  The most obvious are distributing files during patching, software distribution, OS Provisioning, and Agent State communication.  Multicast packets are also used for Peer to Peer or Preferred Server downloads.  The nature of Multicast packets are such that they can easily be lost in a 'noisy' network environment and this can impact the successful implementation of LANDesk multicast functionality.  This utility will help you test multicast communication and determine if High Priority multicast packets are being lost in transit.

More information about Peer to Peer downloading can be found here:

STEP BY STEP:

Option 1:

You can test multicast functionality from one device to another, or from one device to multiple others.  This is a helpful test when peer to peer downloading is not working as expected.

1. Download the attached MulticastNetworkTest utility and unzip it
2. Place the utility in the ldclient folder on two or more test devices; one will be the sender and the others will be listeners
3. Stop the LANDesk Targeted Multicast service on both devices
4. On the listener, run "MulticastnetworkTest.exe listener” from an admin command prompt.
5. On the sender, run “MulticastnetworkTest.exe sender”.  It will look like this:
   
6. The sender will broadcast 10000 packets, 500 of which will be high priority. The listener will record receipt of these packets and the numbers should look like this:
   
   
   

As you can see in this example the listener received all 500 high priority packets although it dropped a few of the low priority.  That is considered normal.  If you find that High Priority packets are being dropped, that indicates a network issue that must be addressed before Multicast features within LDMS can work reliably.

Option 2:

You can cause one device to send out multicast packets and then listen to see if it receives back the same packet.  This is more of a general test.

1. Download the attached MulticastNetworkTest utility and unzip it
2. Place the utility in the ldclient folder on a test device
3. Stop the LANDesk Targeted Multicast service
4. Run MulticastNetworkTest.exe with no arguments

In this mode it will send out a multicast packet once per second. It will also print out a line for each of these messages it receives.  It includes a count in the message, so you can see if any are missed.  So if you run it on one machine, then you should see that it receives a message from itself once per second.  If you run it on 3 machines, you should see that each machine receives the 3 messages from each machine every second.