300-415 Question 286
Single answerA network administrator notices that data flows between branch sites are consuming excessive bandwidth despite enabling Data Redundancy Elimination (DRE) on the Cisco SD-WAN routers. Upon further investigation, the administrator discovers that the benefits of DRE are not being realized. Which of the following could be the reason for this issue?
- A
DRE is only effective on TCP traffic, and the traffic in this case is using UDP.
- B
The DRE cache size on the routers is insufficient to store unique data patterns.
- C
DRE can only be applied to encrypted traffic, but the data flows are unencrypted.
- D
The data flows between branch sites are dynamically changing and lack repetitive patterns.
Show answer and explanation
Correct answer: D
Explanation
Data Redundancy Elimination (DRE) reduces bandwidth usage by identifying and eliminating redundant data patterns in traffic. However, if the data flows lack repetitive patterns or change dynamically, DRE cannot effectively deduplicate the traffic. This is the most likely reason why the administrator is not observing bandwidth savings despite enabling DRE.
- A. Incorrect.
While DRE primarily works at the application level and can process both TCP and UDP traffic, the protocol itself is not the limiting factor for DRE effectiveness.
- B. Incorrect.
Although DRE requires sufficient cache size to store data patterns, the issue described does not specifically point to cache limitations being the root cause.
- C. Incorrect.
DRE is designed to work on unencrypted traffic. If the traffic is encrypted, DRE will not be able to identify redundant patterns. However, this is not the case in the scenario described.
- D. Correct.
DRE relies on identifying repetitive data patterns to eliminate redundancy. If traffic lacks repetitive patterns, DRE cannot provide significant bandwidth savings, which matches the described issue.