If multicast cannot be used, it is possible to use Unicast instead. Please follow the instructions in this article:
if you find that it is enabled on a different IP range (for example, 224.x), you can make the following changes to the file \wasp\webapps\WEB-INF\classes\portal-ext.properties, adding the following lines at the bottom of the file:
For "address.to.uim.database", put the address of your UIM database server. In the above example port 1433 was used as this reflects the standard port for a Microsoft SQL server, but your environment may differ depending on your database platform.
This does not necessarily have to be the database server, but it has to be the address of a machine that both UMP nodes can freely communicate with, so the database server makes sense.