SSCP Network and Communications Security Practice Question
A network administrator is troubleshooting a DNS poisoning attack. Which TWO countermeasures can help prevent such attacks? (Select two)
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Implement DNSSEC to validate DNS responses
DNSSEC validates DNS responses to prevent spoofing, and using secure DNS resolvers (like Quad9 or Cloudflare) can filter malicious domains. Disabling recursion is a best practice but not a direct countermeasure against poisoning. DHCP snooping is for DHCP attacks. Firewalls don't prevent DNS poisoning.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Implement DNSSEC to validate DNS responses
Why this is correct
DNSSEC adds cryptographic signatures to DNS records.
- ✗
Configure firewall rules to block UDP port 53
Why it's wrong here
Blocking port 53 would break DNS entirely.
- ✗
Disable DNS recursion on authoritative servers
Why it's wrong here
Disabling recursion helps prevent cache poisoning on authoritative servers but does not prevent poisoning on resolvers.
- ✓
Use secure DNS resolvers that enforce DNSSEC validation
Why this is correct
Secure resolvers validate DNSSEC and block malicious responses.
- ✗
Enable DHCP snooping on switches
Why it's wrong here
DHCP snooping prevents rogue DHCP servers, not DNS poisoning.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This SSCP practice question is part of Courseiva's free ISC2 certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SSCP exam.