Representations of Domain Name o Fully qualified Domain Name (Fqdn o containing the full name of a host o terminated by a null string(the root also called absolute domain name Example: cSie ntut. edu. tw. o Partially Qualified Domain Name(Pqdn) o not terminated by a null string o used when the name to be solved belongs to the same site o Missing part(suffix) can be supplied by resolver
11 Representations of Domain Name Fully Qualified Domain Name (FQDN) ⚫ containing the full name of a host ⚫ terminated by a null string (the root) ⚫ also called absolute domain name ⚫ Example: csie.ntut.edu.tw. Partially Qualified Domain Name (PQDN) ⚫ not terminated by a null string ⚫ used when the name to be solved belongs to the same site ⚫ Missing part (suffix) can be supplied by resolver
fQdN and PQDN FODN PQDN challenger. atc. fda. edu challenger. atc thda. edu cs hmme. com cs hmme www.funny.int WWW
12 FQDN and PQDN
Domain o a subtree of the domain name space o a domain may itself be divided into domains(subdomains
13 Domain A subtree of the domain name space A domain may itself be divided into domains (subdomains)
Domains com edt Domain Domain omain Domain OO Domain 14
14 Domains
Distribution of Name Space o The domain name space should be stored o Using one computer to store the whole name space Is o Inefficient: heavy load on the server o Unreliable: any failure makes data inaccessible 15
15 Distribution of Name Space The domain name space should be stored. Using one computer to store the whole name space is ⚫ Inefficient: heavy load on the server ⚫ Unreliable: any failure makes data inaccessible