Which of the following routing protocols needs to have an autonomous system set in order...

EIGRP (Enhanced Interior Gateway Routing Protocol) is a Cisco proprietary advanced distance-vector routing protocol. While it operates within an Autonomous System (AS), it requires the AS number to be configured for routers to recognize each other as EIGRP neighbors.

OSPF (Open Shortest Path First) uses areas and routers must be in the same area to form adjacencies, but it doesn't require AS numbers in the same way.

FHRP (First Hop Redundancy Protocol) is not a routing protocol but a group of protocols (e.g., HSRP, VRRP) to ensure high availability at the default gateway level.

RIP (Routing Information Protocol) does not use autonomous system numbers.

???? Reference:

CompTIA Network+ N10-009 Official Objectives: 3.1 – Compare and contrast various routing technologies.

===========