G lcsmitedu 85 neither manageable nor ecient as

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Mul8ple levels, e.g. full name à༎ email à༎ IP address à༎ Ethernet address •  Resolu8on (or lookup) is mapping a name to an address Name, e.g. “Andy Tanenbaum,” or “flits.cs.vu.nl” Lookup Address, e.g. “Vrijie Universiteit, Amsterdam” or IPv4 “” Directory 101 4 11/26/13 Before the DNS – HOSTS.TXT •  Directory was a file HOSTS.TXT regularly retrieved for all hosts from a central machine at the NIC (Network Informa8on Center) •  Names were ini8ally flat, became hierarchical (e.g., lcs.mit.edu) ~85 •  Neither manageable nor efficient as the ARPANET grew … 102 DNS •  A naming service to map between host names and their IP addresses (and more) –  www.uwa.edu.au à༎ •  Goals: –  Easy to manage (esp. with mul8ple par8es) –  Efficient (good performance, few resources) •  Approach: –  Distributed directory based on a hierarchical namespace –  Automated protocol to 8e pieces together 103 5 11/26/13 DNS Namespace •  Hierarchical, star8ng from “.” (dot, typically omifed) 104 TLDs (Top- Level Domains) •  Run by ICANN (Internet Corp. for Assigned Names and Numbers) –  Star8ng in ‘98; naming is financial, poli8cal, and interna8onal J༄ •  22+ generic TLDs –  Ini8ally .com, .edu , .gov., .mil, .org, .net –  Added .aero, .museum, etc. from ’01 through .xxx in ’11 –  Different TLDs have different usage policies •  ~250 country code TLDs –  Two lefers, e.g., “.au”, plus interna8onal characters since 2010 –  Widely commercialized, e.g., .tv (Tuvalu) –  Many domain hacks, e.g., instagr.am (Armenia), goo.gl (Greenland) 105 6 11/26/13...
View Full Document

This document was uploaded on 04/04/2014.

Ask a homework question - tutors are online