By default, the XDMCP broadcast address is 255.255.255.255, which is called a "limited broadcast." A limited broadcast is not forwarded by routers. If routers on your network are configured to pass specific subnet broadcasts but not a universal broadcast, changing the default value of may allow the broadcast to reach more subnets.
If you have multiple subnets and you want an XDMCP broadcast to reach all of them, you can specify multiple IP addresses in this text box. Separate the entries with a comma.
The following example will list all of the addresses in the subnet 188.8.131.52, plus the particular host whose IP address is 184.108.40.206.
Host names can be used for individual hosts. IP addresses must be used to designate subnet-directed broadcasts.