ITPEC FE Subject A April 2026 Question 26

Topic: NetworksAlso asked in October 2020

Which of the following is a role played by a DNS in a TCP/IP network?

Explanation

Associating domain or host names with IP addresses — DNS is the name resolution service of a TCP/IP network.

A client asks a DNS server for a name such as www.example.com and receives its IP address; a reverse lookup maps an address back to a name. DNS is a distributed, hierarchical database: root servers point to top-level domain servers, which point to the authoritative server of each domain.

Answer (b)

Why not others:

  • •(a) — leasing an unused address from a pool to a PC or printer is DHCP
  • •(c) — converting private addresses used inside a company into global ones is NAT
  • •(d) — calling a server program by its name alone, without knowing where it runs, is location transparency provided by middleware such as remote procedure calls; DNS names hosts, not the programs on them

Key rule: DNS answers "which address has this name", DHCP hands addresses out, and NAT rewrites them: three different jobs that all involve IP addresses.

Networks · AI-written, may contain errors

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