Infoblox NIOS-DDI-Expert Practice Exams
Last updated on Oct 22,2026- Exam Code: NIOS-DDI-Expert
- Exam Name: Infoblox Qualified NIOS DDI Expert - INE
- Certification Provider: Infoblox
- Latest update: Oct 22,2026
Question #81
A firewall change has interrupted the DHCP Failover communication between two DHCP Failover peers. Both peers are still online and can communicate to clients, but the state is now COMMUNICATIONS INTERRUPTED.
What should the administrator do?
- A . Nothing
- B . Place the Primary peer into PARTNER-DOWN
- C . Place the secondary peer into PARTNER-DOWN
- D . Change split value
Correct Answer: C
C
Explanation:
Comprehensive and Detailed In-Depth
DHCP Failover peers sync leases via TCP 647.
A firewall blocking this shifts the state to COMMUNICATIONS-INTERRUPTED:
State Impact:
Both peers serve existing clients and limited new leases (via MCLT).
No sync occurs, risking lease conflicts if prolonged.
Best Action: Manually set one peer to PARTNER-DOWN (Grid > DHCP > Failover > Edit), giving the other full pool control to avoid conflicts.
Why Secondary: Conventionally, the secondary is set to PARTNER-DOWN, letting the primary take over as the authoritative peer (per Infoblox best practices).
Options:
A: Doing nothing risks conflicts if new leases exceed MCLT capacity. Incorrect long-term.
B: Primary to PARTNER-DOWN cedes control to secondary, less standard. Incorrect.
C: Secondary to PARTNER-DOWN empowers primary, aligning with failover design. Correct.
D: Changing split value doesn’t address sync loss. Incorrect.
Practical Example: In an INE lab, you’d simulate this, set secondary to PARTNER-DOWN, and troubleshoot lease consistency post-firewall fix.
Reference: Infoblox NIOS Administrator Guide C DHCP Failover States; INE Course Content: NIOS DDI DHCP Troubleshooting.
C
Explanation:
Comprehensive and Detailed In-Depth
DHCP Failover peers sync leases via TCP 647.
A firewall blocking this shifts the state to COMMUNICATIONS-INTERRUPTED:
State Impact:
Both peers serve existing clients and limited new leases (via MCLT).
No sync occurs, risking lease conflicts if prolonged.
Best Action: Manually set one peer to PARTNER-DOWN (Grid > DHCP > Failover > Edit), giving the other full pool control to avoid conflicts.
Why Secondary: Conventionally, the secondary is set to PARTNER-DOWN, letting the primary take over as the authoritative peer (per Infoblox best practices).
Options:
A: Doing nothing risks conflicts if new leases exceed MCLT capacity. Incorrect long-term.
B: Primary to PARTNER-DOWN cedes control to secondary, less standard. Incorrect.
C: Secondary to PARTNER-DOWN empowers primary, aligning with failover design. Correct.
D: Changing split value doesn’t address sync loss. Incorrect.
Practical Example: In an INE lab, you’d simulate this, set secondary to PARTNER-DOWN, and troubleshoot lease consistency post-firewall fix.
Reference: Infoblox NIOS Administrator Guide C DHCP Failover States; INE Course Content: NIOS DDI DHCP Troubleshooting.
Question #82
By default, how do peers in an Infoblox DHCP Failover association operate in NORMAL mode?
- A . The primary peer answers roughly half of the lease requests and the secondary answers the other half
- B . Whichever peer receives the request first will answer the request
- C . The primary answers all lease requests up to the utilization threshold, then the secondary answers requests
- D . The primary answers all lease requests
Correct Answer: A
A
Explanation:
Comprehensive and Detailed In-Depth
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.
Reference: Infoblox NIOS Administrator Guide C DHCP Failover; INE Course Content: NIOS DDI DHCP Troubleshooting.
A
Explanation:
Comprehensive and Detailed In-Depth
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.
Reference: Infoblox NIOS Administrator Guide C DHCP Failover; INE Course Content: NIOS DDI DHCP Troubleshooting.
Question #83
What can an administrator do with an Option Filter in NIOS?
- A . Match on any DHCP options provided by the client
- B . Match on any DHCP options provided by the server
- C . Match only vendor-specific options such as Option 60
- D . Match only on device types
Correct Answer: A
A
Explanation:
Comprehensive and Detailed In-Depth
In NIOS, DHCP Option Filters allow administrators to define rules for matching DHCP client requests based on the options they send in their DHCP packets. These filters are highly flexible and can match any DHCP option provided by the client, such as Option 55 (Parameter Request List), Option 60 (Vendor Class Identifier), or custom options. This enables precise DHCP policy enforcement, like assigning specific IP ranges or options to certain devices.
Option B is incorrect because filters apply to client requests, not server responses.
Option C is too narrow―while Option 60 is common, filters aren’t limited to vendor-specific options.
Option D is vague and incorrect; device type matching is a subset of option matching. The INE course covers DHCP troubleshooting, including filter configuration.
Reference: Infoblox NIOS Administrator Guide C DHCP Option Filters; INE Course Content: NIOS DDI DHCP Troubleshooting.
A
Explanation:
Comprehensive and Detailed In-Depth
In NIOS, DHCP Option Filters allow administrators to define rules for matching DHCP client requests based on the options they send in their DHCP packets. These filters are highly flexible and can match any DHCP option provided by the client, such as Option 55 (Parameter Request List), Option 60 (Vendor Class Identifier), or custom options. This enables precise DHCP policy enforcement, like assigning specific IP ranges or options to certain devices.
Option B is incorrect because filters apply to client requests, not server responses.
Option C is too narrow―while Option 60 is common, filters aren’t limited to vendor-specific options.
Option D is vague and incorrect; device type matching is a subset of option matching. The INE course covers DHCP troubleshooting, including filter configuration.
Reference: Infoblox NIOS Administrator Guide C DHCP Option Filters; INE Course Content: NIOS DDI DHCP Troubleshooting.