A local DNS server receives a request to resolve the name www.mycom.com.au There is no entry for this name in the local hosts file or the cache. What steps will the local DNS server do to resolve this name to an IP address?
Try an answer before revealing the guidance below.
Key Concepts
- Local resolver
- Root DNS
- TLD DNS
- Authoritative DNS
- A record
- TTL
Answer Approach
- Start with the cache miss.
- Follow referrals through root and relevant TLD servers.
- Ask the authoritative server for the address record.
- Cache the answer and reply to the client.
Full Answer
Answer status: Verified against study notes. Revision notes, not an official marking scheme.
The local resolver queries a root server, which refers it toward the .au hierarchy. It follows the relevant TLD referrals, including com.au as needed, to the authoritative server for mycom.com.au. It requests the address record for www.mycom.com.au, caches the returned result according to its TTL, and returns the IP address to the client.
Shortcuts: K concepts · A approach · F answer · R reviewed · B bookmark · ← / → previous / next