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Network Perimeter ProtectionhardMultiple ChoiceObjective-mapped

CND Network Perimeter Protection Practice Question

An enterprise firewall is experiencing asymmetric routing where TCP SYN packets enter through Firewall A, but the return SYN-ACK packets exit through Firewall B due to dynamic routing changes. What firewall feature must be enabled to synchronize connection state tables between Firewall A and Firewall B and prevent connection drops?

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

Stateful Session Synchronization (Cluster State Sync)

Stateful firewalls require session synchronization (such as Cisco Stateful Failover or Palo Alto HA session sync) to share connection state tables across cluster nodes in asymmetric paths.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • Strict TCP handshake validation

    Why it's wrong here

    Strict validation would cause firewalls to drop asynchronous return packets.

  • Unicast RPF (Reverse Path Forwarding)

    Why it's wrong here

    uRPF checks source IP routability to prevent spoofing, often dropping asymmetric traffic.

  • Stateful Session Synchronization (Cluster State Sync)

    Why this is correct

    Session synchronization shares active session tables across firewalls to handle asymmetric routing.

  • NAT hairpinning

    Why it's wrong here

    NAT hairpinning allows internal clients to access internal servers via public IPs.

Visual reference

Client Server SYN (seq=100) SYN-ACK (seq=200, ack=101) ACK (ack=201) Connection established — data transfer begins

Quick reference

Asymmetric Encryption Algorithm Comparison

AlgorithmKey ExchangeSignaturesEquivalent Security KeyNotes
RSA-3072YesYes128-bitWidely deployed; slow for bulk data
ECDSA P-256NoYes128-bitFast signatures; standard TLS certs
ECDH / ECDHEYesNo128-bitPerfect forward secrecy in TLS 1.3
DH / DHEYesNo128-bit (3072-bit key)Replaced by ECDHE in modern TLS
Ed25519NoYes~128-bitSSH keys, modern PKI

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JA

Written and reviewed by Johnson Ajibi, MSc IT Security

Senior Network & Security Engineer · founder of Courseiva

Last reviewed August 2026 · checked against the official EC-Council exam blueprint

This CND practice question is part of Courseiva's free EC-Council 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 CND exam.