Are you behind a Router? This appears to be normal traffic from a Router. When I defined a trusted network for my router these entires disappeared from my logs.
It is blocked because it is essentially an unsolicited inbound connection (it can be a complex explanation; I’m trying to keep it simple…).
Typically this UDP connection is related to your DHCP lease, and vital to maintaining your internet connection. If you have a router, as Anderow pointed out it will be coming from the IP of your router. You can verify the authenticity of the source by going to Start/Run and typing “cmd” (no quotes). At the DOS prompt, type “ipconfig /all”. This will give you information about your network, such as DHCP Server, DNS Server, Default Gateway (ie, router or modem), IP address (internal or external, as applicable), etc.
The “Network” you’ll want to create as per Anderow’s post should include the DHCP & DNS Server IP addresses. This should eliminate these blocks. If you have any questions about creating the trusted network rules, please let us know.