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CT320 | Lecture / TopLevelDomains

CT320: Network and System Administration

Fall 2019

Top Level Domains

Show Lecture.TopLevelDomains as a slide show.

CT320 Top Level Domains

Top Level Domains Trivia

https://data.iana.org/TLD/tlds-alpha-by-domain.txt

The Original Top-Level Domains

About 1984, the original TLDs were created:

Country Codes

There are 248 two-letter ASCII country codes, as assigned in ISO 3166-1:

.ac .ad .ae .af .ag .ai .al .am .ao .aq .ar .as .at .au .aw .ax .az .ba .bb .bd .be .bf .bg .bh .bi .bj .bm .bn .bo .br .bs .bt .bv .bw .by .bz .ca .cc .cd .cf .cg .ch .ci .ck .cl .cm .cn .co .cr .cu .cv .cw .cx .cy .cz .de .dj .dk .dm .do .dz .ec .ee .eg .er .es .et .eu .fi .fj .fk .fm .fo .fr .ga .gb .gd .ge .gf .gg .gh .gi .gl .gm .gn .gp .gq .gr .gs .gt .gu .gw .gy .hk .hm .hn .hr .ht .hu .id .ie .il .im .in .io .iq .ir .is .it .je .jm .jo .jp .ke .kg .kh .ki .km .kn .kp .kr .kw .ky .kz .la .lb .lc .li .lk .lr .ls .lt .lu .lv .ly .ma .mc .md .me .mg .mh .mk .ml .mm .mn .mo .mp .mq .mr .ms .mt .mu .mv .mw .mx .my .mz .na .nc .ne .nf .ng .ni .nl .no .np .nr .nu .nz .om .pa .pe .pf .pg .ph .pk .pl .pm .pn .pr .ps .pt .pw .py .qa .re .ro .rs .ru .rw .sa .sb .sc .sd .se .sg .sh .si .sj .sk .sl .sm .sn .so .sr .ss .st .su .sv .sx .sy .sz .tc .td .tf .tg .th .tj .tk .tl .tm .tn .to .tr .tt .tv .tw .tz .ua .ug .uk .us .uy .uz .va .vc .ve .vg .vi .vn .vu .wf .ws .ye .yt .za .zm .zw

Non-country geographic domains

In addition to the two-letter country code domains, there are a growing number of geographic domains, including:

https://wikipedia.org/wiki/List_of_Internet_top-level_domains#Geographic_top-level_domains

.US

Unfortunately, .us is a disaster, due to the overly-complex naming scheme enforced until 2002:

That’s one .gov, one .org, and one .com. Uniformity!

Map

Second Wave

In the early 2000s, several TLDs were added:

Speculation

As of October 2017, applin.com was available for $3,495 00.

Non-International Domains

We are in a speculation bubble, as top-level domains are being sold for $$$. Current top-level domains:

.aaa
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.aarp
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.abb .abbott
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.abbvie .abc .able .abogado
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.abudhabi
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.ac
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.academy .accenture
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.accountant
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.accountants
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.aco .actor
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.ad .ads .adult .ae .aeg .aero .aetna .af .afl .africa .ag .agakhan .agency .ai .aig .airbus .airforce .airtel .akdn .al .alibaba .alipay .allfinanz .allstate .ally .alsace .alstom .am .amazon .americanexpress
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.americanfamily
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.amex .amfam .amica .amsterdam .analytics .android .anquan .anz .ao .aol .apartments .app .apple .aq .aquarelle .ar .arab .aramco .archi .army .arpa .art .arte .as .asda .asia .associates .at .athleta .attorney .au .auction .audi .audible .audio .auspost .author .auto .autos .aw .aws .ax .axa .az .azure .ba .baby .baidu .banamex .band .bank .bar .barcelona .barclaycard .barclays .barefoot .bargains .baseball .basketball .bauhaus .bayern .bb .bbc .bbt .bbva .bcg .bcn .bd .be .beats .beauty .beer .berlin .best .bestbuy .bet .bf .bg .bh .bharti .bi .bible .bid .bike .bing .bingo .bio .biz .bj .black .blackfriday .blockbuster .blog .bloomberg .blue .bm .bms .bmw .bn .bnpparibas .bo .boats .boehringer .bofa .bom .bond .boo .book .booking .bosch .bostik .boston .bot .boutique .box .br .bradesco .bridgestone .broadway .broker .brother .brussels .bs .bt .build .builders .business .buy .buzz .bv .bw .by .bz .bzh .ca .cab .cafe .cal .call .calvinklein .cam .camera .camp .canon .capetown .capital .capitalone .car .caravan .cards .care .career .careers .cars .casa .case .cash .casino .cat .catering .catholic .cba .cbn .cbre .cc .cd .center .ceo .cern .cf .cfa .cfd .cg .ch .chanel .channel .charity .chase .chat .cheap .chintai .christmas .chrome .church .ci .cipriani .circle .cisco .citadel .citi .citic .city .ck .cl .claims .cleaning .click .clinic .clinique .clothing .cloud .club .clubmed .cm .cn .co .coach .codes .coffee .college .cologne .com .commbank .community .company .compare .computer .comsec .condos .construction
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.consulting .contact .contractors .cooking .cool .coop .corsica .country .coupon .coupons .courses .cpa .cr .credit .creditcard .creditunion .cricket .crown .crs .cruise .cruises .cu .cuisinella .cv .cw .cx .cy .cymru .cyou .cz .dad .dance .data .date .dating .datsun .day .dclk .dds .de .deal .dealer .deals .degree .delivery .dell .deloitte .delta .democrat .dental .dentist .desi .design .dev .dhl .diamonds .diet .digital .direct .directory .discount .discover .dish .diy .dj .dk .dm .dnp .do .docs .doctor .dog .domains .dot .download .drive .dtv .dubai .dupont .durban .dvag .dvr .dz .earth .eat .ec .eco .edeka .edu .education .ee .eg .email .emerck .energy .engineer .engineering .enterprises .epson .equipment .er .ericsson .erni .es .esq .estate .et .eu .eurovision .eus .events .exchange .expert .exposed .express .extraspace .fage .fail .fairwinds .faith .family .fan .fans .farm .farmers .fashion .fast .fedex .feedback .ferrari .ferrero .fi .fidelity .fido .film .final .finance .financial .fire .firestone .firmdale .fish .fishing .fit .fitness .fj .fk .flickr .flights .flir .florist .flowers .fly .fm .fo .foo .food .football .ford .forex .forsale .forum .foundation .fox .fr .free .fresenius .frl .frogans .frontier .ftr .fujitsu .fun .fund .furniture .futbol .fyi .ga .gal .gallery .gallo .gallup .game .games .gap .garden .gay .gb .gbiz .gd .gdn .ge .gea .gent .genting .george .gf .gg .ggee .gh .gi .gift .gifts .gives .giving .gl .glass .gle .global .globo .gm .gmail .gmbh .gmo .gmx .gn .godaddy .gold .goldpoint .golf .goodyear .goog .google .gop .got .gov .gp .gq .gr .grainger .graphics .gratis .green .gripe .grocery .group .gs .gt .gu .gucci .guge .guide .guitars .guru .gw .gy .hair .hamburg .hangout .haus .hbo .hdfc .hdfcbank .health .healthcare .help .helsinki .here .hermes .hiphop .hisamitsu .hitachi .hiv .hk .hkt .hm .hn .hockey .holdings .holiday .homedepot .homegoods .homes .homesense .honda .horse .hospital .host .hosting .hot .hotels .hotmail .house .how .hr .hsbc .ht .hu .hughes .hyatt .hyundai .ibm .icbc .ice .icu .id .ie .ieee .ifm .ikano .il .im .imamat .imdb .immo .immobilien .in .inc .industries .infiniti .info .ing .ink .institute .insurance .insure .int .international
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.intuit .investments .io .ipiranga .iq .ir .irish .is .ismaili .ist .istanbul .it .itau .itv .jaguar .java .jcb .je .jeep .jetzt .jewelry .jio .jll .jm .jmp .jnj .jo .jobs .joburg .jot .joy .jp .jpmorgan .jprs .juegos .juniper .kaufen .kddi .ke .kerryhotels .kerryproperties .kfh .kg .kh .ki .kia .kids .kim .kindle .kitchen .kiwi .km .kn .koeln .komatsu .kosher .kp .kpmg .kpn .kr .krd .kred .kuokgroup .kw .ky .kyoto .kz .la .lacaixa .lamborghini .lamer .land .landrover .lanxess .lasalle .lat .latino .latrobe .law .lawyer .lb .lc .lds .lease .leclerc .lefrak .legal .lego .lexus .lgbt .li .lidl .life .lifeinsurance .lifestyle .lighting .like .lilly .limited .limo .lincoln .link .live .living .lk .llc .llp .loan .loans .locker .locus .lol .london .lotte .lotto .love .lpl .lplfinancial .lr .ls .lt .ltd .ltda .lu .lundbeck .luxe .luxury .lv .ly .ma .madrid .maif .maison .makeup .man .management .mango .map .market .marketing .markets .marriott .marshalls .mattel .mba .mc .mckinsey .md .me .med .media .meet .melbourne .meme .memorial .men .menu .merckmsd .mg .mh .miami .microsoft .mil .mini .mint .mit .mitsubishi .mk .ml .mlb .mls .mm .mma .mn .mo .mobi .mobile .moda .moe .moi .mom .monash .money .monster .mormon .mortgage .moscow .moto .motorcycles .mov .movie .mp .mq .mr .ms .msd .mt .mtn .mtr .mu .museum .music .mv .mw .mx .my .mz .na .nab .nagoya .name .navy .nba .nc .ne .nec .net .netbank .netflix .network .neustar .new .news .next .nextdirect .nexus .nf .nfl .ng .ngo .nhk .ni .nico .nike .nikon .ninja .nissan .nissay .nl .no .nokia .norton .now .nowruz .nowtv .np .nr .nra .nrw .ntt .nu .nyc .nz .obi .observer .office .okinawa .olayan .olayangroup .ollo .om .omega .one .ong .onl .online .ooo .open .oracle .orange .org .organic .origins .osaka .otsuka .ott .ovh .pa .page .panasonic .paris .pars .partners .parts .party .pay .pccw .pe .pet .pf .pfizer .pg .ph .pharmacy .phd .philips .phone .photo .photography .photos .physio .pics .pictet .pictures .pid .pin .ping .pink .pioneer .pizza .pk .pl .place .play .playstation .plumbing .plus .pm .pn .pnc .pohl .poker .politie .porn .post .pr .praxi .press .prime .pro .prod .productions .prof .progressive .promo .properties .property .protection .pru .prudential .ps .pt .pub .pw .pwc .py .qa .qpon .quebec .quest .racing .radio .re .read .realestate .realtor .realty .recipes .red .redumbrella .rehab .reise .reisen .reit .reliance .ren .rent .rentals .repair .report .republican .rest .restaurant .review .reviews .rexroth .rich .richardli .ricoh .ril .rio .rip .ro .rocks .rodeo .rogers .room .rs .rsvp .ru .rugby .ruhr .run .rw .rwe .ryukyu .sa .saarland .safe .safety .sakura .sale .salon .samsclub .samsung .sandvik .sandvikcoromant .sanofi .sap .sarl .sas .save .saxo .sb .sbi .sbs .sc .scb .schaeffler .schmidt .scholarships .school .schule .schwarz .science .scot .sd .se .search .seat .secure .security .seek .select .sener .services .seven .sew .sex .sexy .sfr .sg .sh .shangrila .sharp .shell .shia .shiksha .shoes .shop .shopping .shouji .show .si .silk .sina .singles .site .sj .sk .ski .skin .sky .skype .sl .sling .sm .smart .smile .sn .sncf .so .soccer .social .softbank .software .sohu .solar .solutions .song .sony .soy .spa .space .sport .spot .sr .srl .ss .st .stada .staples .star .statebank .statefarm .stc .stcgroup .stockholm .storage .store .stream .studio .study .style .su .sucks .supplies .supply .support .surf .surgery .suzuki .sv .swatch .swiss .sx .sy .sydney .systems .sz .tab .taipei .talk .taobao .target .tatamotors .tatar .tattoo .tax .taxi .tc .tci .td .tdk .team .tech .technology .tel .temasek .tennis .teva .tf .tg .th .thd .theater .theatre .tiaa .tickets .tienda .tips .tires .tirol .tj .tjmaxx .tjx .tk .tkmaxx .tl .tm .tmall .tn .to .today .tokyo .tools .top .toray .toshiba .total .tours .town .toyota .toys .tr .trade .trading .training .travel .travelers .travelersinsurance
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.trust .trv .tt .tube .tui .tunes .tushu .tv .tvs .tw .tz .ua .ubank .ubs .ug .uk .unicom .university .uno .uol .ups .us .uy .uz .va .vacations .vana .vanguard .vc .ve .vegas .ventures .verisign .versicherung .vet .vg .vi .viajes .video .vig .viking .villas .vin .vip .virgin .visa .vision .viva .vivo .vlaanderen .vn .vodka .volvo .vote .voting .voto .voyage .vu .wales .walmart .walter .wang .wanggou .watch .watches .weather .weatherchannel .webcam .weber .website .wed .wedding .weibo .weir .wf .whoswho .wien .wiki .williamhill .win .windows .wine .winners .wme .wolterskluwer .woodside .work .works .world .wow .ws .wtc .wtf .xbox .xerox .xihuan .xin .xxx .xyz .yachts .yahoo .yamaxun .yandex .ye .yodobashi .yoga .yokohama .you .youtube .yt .yun .za .zappos .zara .zero .zip .zm .zone .zuerich .zw
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2248
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Punycode

DNS requires ASCII-only. However, the Punycode encoding scheme allows for domains in all languages, e.g., Chinese, Arabic, Hindi, etc.

Here are several examples.

Reserved

Reserved DomainSays Who
.exampleRFC 6761
.example.comRFC 6761
.example.netRFC 6761
.example.orgRFC 6761
.invalidRFC 6761
.localhostRFC 6761
.testRFC 6761
.localRFC 6762
.onionRFC 7686

There are also reserved IP addresses.