DevNet Associate (DEVASC) v1.0Network FundamentalsMedium
A security engineer is analyzing a network capture and observes a significant amount of traffic on UDP port 53. The traffic consists of numerous small queries and responses. Based on this observation, which network service is most likely generating this traffic?
- ADNS
- BNTP
- CSSH
- DDHCP
Show answer & explanationAnswer & explanation
Correct answer: A. DNS
UDP port 53 is the standard port for the Domain Name System (DNS), which translates domain names to IP addresses. DNS queries and responses are typically small and frequent.
Why the other options are wrong
- B. NTP (Network Time Protocol) uses UDP port 123 for time synchronization.
- C. SSH (Secure Shell) uses TCP port 22 for secure remote access.
- D. DHCP (Dynamic Host Configuration Protocol) uses UDP ports 67 and 68 for IP address assignment.
DNS (Domain Name System)
DNS is a hierarchical and decentralized naming system for computers, services, or other resources connected to the Internet or a private network.
- Translates human-readable domain names into machine-readable IP addresses.
- Primarily uses UDP port 53 for queries, TCP port 53 for zone transfers.
- Essential for web browsing and many other internet services.
Memory trick: UDP: 'Unreliable, Datagrams, Ports!'