In web infrastructure, DNS-based load balancing distributes requests by returning different IP addresses for the same host name, not by routing a single IP address at the TCP/IP level. Based on this, is the statement “A load-balancing approach where requests to one IP address are distributed among multiple servers at the TCP/IP routing level is DNS balancing” accurate?
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ACorrect
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BIncorrect
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COnly accurate when anycast is used
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DAccurate for reverse proxies but not DNS
Answer
Correct Answer: Incorrect
Explanation
Introduction / Context:This question checks whether you can distinguish Domain Name System (DNS) load balancing from lower-layer load-distribution techniques. DNS round-robin balances by handing out different IP addresses at name-resolution time, while layer-4 or layer-7 load balancers route traffic for a single virtual IP to multiple back-end servers.
Given Data / Assumptions:
- The statement describes a single IP address with distribution occurring “at the TCP/IP routing level.”
- DNS balancing typically involves multiple A/AAAA records for one host name.
- Layer-4/7 load balancers and reverse proxies can front a single virtual IP and fan out requests.
Concept / Approach:DNS balancing operates at name resolution: clients receive one of several IPs. Routing or proxy-based load balancing operates after resolution, often using a single virtual IP that distributes traffic internally. The prompt conflates these approaches, attributing TCP/IP–level single-IP routing to DNS, which is inaccurate.
Step-by-Step Solution:
Identify what DNS does: map a name to one or more IP addresses.Recall how DNS balancing works: multiple records → clients hit different servers.Contrast with L4/L7 balancers: one virtual IP, internal distribution to many servers.Conclude: the described mechanism is not DNS balancing → statement is inaccurate.Verification / Alternative check:Check common architectures: “DNS round robin” vs “reverse proxy/ADC.” Only the latter uses one VIP to split traffic post-resolution.
Why Other Options Are Wrong:
- Correct: would wrongly accept the conflation.
- Only accurate when anycast is used: anycast still uses DNS to a single IP advertised from many locations; it is not DNS round robin at the TCP routing level as stated.
- Accurate for reverse proxies but not DNS: reinforces that the statement is not describing DNS balancing.
Common Pitfalls:Confusing DNS round robin with VIP-based load balancers; assuming DNS is session-aware (it is not).
Final Answer:Incorrect