What occurs when summarizing Type 5 external LSAs?

When summarizing Type 5 external LSAs (Link-State Advertisements) in OSPF (Open Shortest Path First), a null0 entry is indeed created for the summary route. This null0 interface acts as a black hole, meaning that any traffic that matches the summarized route will be discarded instead of forwarded.

The creation of a null0 entry serves an important purpose in preventing routing loops and managing the traffic flow effectively. By summarizing the routes and creating a corresponding null0 entry, the OSPF routing table can optimize the routing process and improve efficiency.

Additionally, while other options suggest various scenarios related to Type 5 LSAs, they do not accurately describe what occurs during the summarization process. Summarization does not require static routes, and while routes can be filtered, that is not the inherent result of summarizing Type 5 LSAs. Also, summarizing Type 5 LSAs is indeed possible, contrary to what might be suggested about the second choice.