Doing a port scan of our bordermanager server from the outside shows
21
open UDP Ports....

39, 42, 43, 53, 67, 68, 69, 88, 111, 123, 135, 137, 138, 143, 161,
162,
445, 514, 517, 520, 749...

How do I block these open ports from being visible to the outside
world,
and what, if any ramifications are there for doing so?