Topic

DNS

3 questions in this topic.

2013 Q1(d)Application LayerDNS· 5 marks

Explain how caching is used in the Domain Name System (DNS) during an iterative query. Specify what information is cached at the local host, the local DNS, the root DNS, the Top Level Domain (TLD) DNS and the authoritative DNS. Be sure to include only cached information not all information stored.

name resolutioncacheTTL

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2014 Q1(d)Application LayerDNS· 4 marks

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?

name resolutioniterative query

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2015 Q1(d)Application LayerDNS· 2 marks

Give two reasons why iterative DNS queries are preferred to recursive DNS queries. Explain your answer.

name resolutionrecursive query

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