Comprehensive and Detailed In-Depth Explanation:DHCP Failover in NIOS ensures redundancy and load balancing between primary and secondary peers in NORMAL mode:
* Default Behavior:The lease pool is split (typically 50/50 unless customized via "split" settings), and each peer manages its portion. Clients send DHCPDISCOVER broadcasts, and relays (or direct requests) distribute them to both peers. The peers coordinate via TCP 647, ensuring:
* Primary answers from its half.
* Secondary answers from its half.
* Load is roughly balanced (not precisely 50/50 due to relay behavior).
* Options:
* A:Matches the default split-pool design, where peers share the load. Correct.
* B:"First come, first serve" isn't how failover works-peers don't race; they use pool allocation.
Incorrect.
* C:No utilization threshold triggers a switch-both peers serve concurrently from their pools.
Incorrect.
* D:Primary-only answering defeats failover's redundancy and balancing. Incorrect.
* Practical Example:In an INE lab, you'd configure a 50/50 split, simulate client requests, and troubleshoot lease distribution via DHCP logs, verifying NORMAL mode behavior.References:
Infoblox NIOS Administrator Guide - DHCP Failover; INE Course Content: NIOS DDI DHCP Troubleshooting.