I am curious as to whether udp multicast creates a lot of unnecessary traffic on an internal LAN.
I assume the obvious answer to me is yes, but is it enough to congest the switch and slow down all other traffic?
If machines are using DHCP and IP addresses are not consistently assigned to the same node, I am thinking the best way to send data is via multicast.
Best Answer
Not necessarily. Switches which support IGMP snooping can listen in on IGMP requests from hosts, and send only to those switch ports where hosts have requested to become members of the multicast group. It's a little more complicated if you have multiple switches in the same broadcast domain. How you configure your switch depends on the switch model.
A router will not forward multicasts unless you have configured multicast routing on the router. How you configure that is dependent on the router model.