CyberCertPrepNetwork FundamentalsDNS & DHCPEASYFree question
What DHCP option provides a client with its domain name suffix, and how is it used for hostname resolution?
- A.DHCP Option 15 (Domain Name): the DHCP server provides the DNS domain name (e.g., 'corp.local'); the client appends this suffix to unqualified hostnames (e.g., typing 'fileserver' resolves to 'fileserver.corp.local'). Option 119 (Domain Search List) provides an ordered list of suffixes to try
- B.DHCP Option 6 provides the domain suffix; Option 15 provides the DNS server IP addresses
- C.DHCP Option 15 is the subnet mask; it is not related to DNS domain name configuration
- D.Domain suffixes must be manually configured on each client; DHCP cannot distribute domain name information
Why A is correct
DHCP DNS options: Option 6 = DNS Servers (IP addresses), Option 15 = Domain Name (primary search suffix), Option 119 = Domain Search (RFC 3397, ordered list of search domains). When a user types 'ping fileserver', the OS checks the search list: try 'fileserver.corp.local', 'fileserver.subdomain.corp.local', etc. In Active Directory environments, the domain name (from Option 15 or DHCP settings pushed by AD) ensures users can reach DC, file servers, and internal services by short name. Option 119 is preferred over Option 15 when multiple search domains are needed (e.g., multi-forest AD).
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