This chapter covers
- How FHRPs provide a redundant default gateway for end hosts
- The three FHRPs used by Cisco routers and their characteristics
- How to configure Cisco’s Hot Standby Router Protocol
When covering STP in chapter 14, I emphasized the importance of redundancy in a LAN. In modern enterprise networks, redundancy plays an essential role in ensuring network reliability and resilience. As businesses increasingly rely on digital operations and processes, network downtime can result in substantial financial losses and damage to one’s reputation. Redundancy safeguards against this by eliminating single points of failure.
Redundancy doesn’t just mean having multiple potential paths to reach destinations within the same LAN; it also means having multiple potential paths to reach destinations outside of the LAN. First hop redundancy protocols (FHRPs), the topic of this chapter, facilitate this by enabling multiple routers to work together, providing a redundant default gateway for hosts in a LAN. FHRPs constitute CCNA exam topic 3.5: Describe the purpose, functions, and concepts of first hop redundancy protocols.