Solution

The correct answer is (A), (D) and (E) Only

EXPLANATION:

• (A) OSPF is based on distance-vector routing protocol. -
  • This statement is NOT CORRECT. OSPF (Open Shortest Path First) is based on a link-state routing protocol, not a distance-vector protocol.
• (B) Both link-state and distance-vector routing are based on the least cost goal. -
  • This statement is CORRECT. Both of these protocols seek the path with the least overall "cost," where cost is a value that represents characteristics like bandwidth, delay, reliability, etc.
• (C) BGP4 is based on the path-vector algorithm. -
  • This statement is CORRECT. The Border Gateway Protocol (BGP) version 4 is based on a path-vector algorithm rather than being purely distance-vector or link-state.
• (D) The three-node instability can be avoided using split horizon combined with poison reverse. -
  • This statement is NOT CORRECT. Both split horizon and poison reverse are methods to prevent routing loops in distance-vector protocols; however, they might not always be able to prevent "count-to-infinity" problems, including certain cases of three-node instability.
• (E) RIP is based on link state algorithm. -
  • This statement is NOT CORRECT. The Routing Information Protocol (RIP) is based on a distance-vector algorithm, not a link-state algorithm.