Examkin

Question

Difficulty: MediumDNS Infrastructure and Record Types

A network administrator is deploying a centralized log management collector that operates using syslog over UDP port 514514. To enable automated client discovery across the enterprise domain, the administrator needs to configure a DNS record that explicitly specifies the service name, transport protocol, port number, priority, weight, and target hostname. Which of the following DNS record configurations correctly meets this requirement?

  1. An SRV record formatted as _syslog._udp.example.com specifying UDP transport, port 514, and pointing to the collector's canonical hostname.Answer
  2. B
    A CNAME record formatted as _syslog.example.com mapping the service name directly to the IPv4 address and port 514 of the log collector server.
  3. C
    An MX record assigned a preference value of 10 mapping port 514 to the log collector server's host domain name.
  4. D
    An SRV record formatted as _syslog._tcp.example.com configuring TCP transport to ensure connection-oriented delivery to port 514.

Answer

An SRV record formatted as _syslog._udp.example.com specifying UDP transport, port 514, and pointing to the collector's canonical hostname.
The correct option correctly uses an SRV record formatted as `_syslog._udp.example.com`. SRV records specify Symbolic Service Names (`_syslog`), Transport Protocol (`_udp`), Domain Name, Priority, Weight, Port number (514514), and Target Hostname.

Step-by-Step Solution

1
Identify the required DNS functionality based on scenario constraints.
The requirement calls for dynamic service location defining service name, transport protocol, port number, priority, weight, and target hostname.
Standard host records (A/AAAA) or alias records (CNAME) only map hostnames to IP addresses or other hostnames; they cannot advertise port numbers or transport protocols.
2
Determine the proper record type and syntax for service location.
Service Location (SRV) records follow the standard naming structure: `_service._proto.name. TTL CLASS SRV priority weight port target`.
SRV records are designed specifically to allow clients to locate servers offering specific services on custom ports.
3
Verify protocol and port parameters against the service requirements.
The service requires syslog over UDP port 514514, which matches `_syslog._udp.example.com` with port `514`.
Choosing `_tcp` instead of `_udp` would direct clients to initiate TCP handshakes, which will fail against a UDP-only syslog listener.

Key Concept

DNS SRV (Service Location) Record Structure and Functionality
Estimated Time:1m 30s
Rate this question

Topics

DNS Infrastructure and Record Types

More questions from this topic