{"id":700,"date":"2020-04-13T13:18:09","date_gmt":"2020-04-13T11:18:09","guid":{"rendered":"http:\/\/tech.sosthe.sk\/?page_id=700"},"modified":"2020-04-13T13:19:03","modified_gmt":"2020-04-13T11:19:03","slug":"adresy-v-ramci-pri-priechode-sietami","status":"publish","type":"page","link":"http:\/\/tech.sosthe.sk\/index.php\/sietove-technologie\/adresy-v-ramci-pri-priechode-sietami\/","title":{"rendered":"Adresy v r\u00e1mci pri prechode sie\u0165ami"},"content":{"rendered":"

Stanica na zdie\u013eanom m\u00e9diu<\/h4>\n

M\u00e1me dve stanice pripojen\u00e9 na zdie\u013eanom m\u00e9diu, \u010do m\u00f4\u017ee by\u0165 napr\u00edklad star\u00e1 verzia\u00a0ethernetu<\/strong><\/em>\u00a0v\u00a0\u00a0topol\u00f3gii zbernice<\/em>\u00a0(bus) alebo be\u017ene pou\u017e\u00edvan\u00e1\u00a0topol\u00f3gia hviezda<\/em> (star), ke\u010f sa ako centr\u00e1lny prvok pou\u017eije hub. Obe stanice maj\u00fa nastaven\u00fa IP adresu a ur\u010den\u00fa sie\u0165 (zadan\u00fa masku subnetu) a sie\u0165ovej karty maj\u00fa MAC adresu.\u00a0Tento sp\u00f4sob sa ozna\u010duje ako\u00a0zdie\u013ean\u00fd ethernet<\/strong><\/em>\u00a0.<\/p>\n

V tomto pr\u00edpade s\u00fa obe stanice v rovnakej sieti (rovnakom subnete), tak\u017ee d\u00f4jde k\u00a0 priamemu doru\u010deniu<\/em><\/strong>.<\/p>\n

Ak chce\u00a0modr\u00e1 stanica<\/em><\/strong>\u00a0posla\u0165 d\u00e1ta\u00a0\u010dervenej stanici<\/em><\/strong>, tak najprv vytvoria\u00a0ethernetov\u00fd r\u00e1mec<\/em>:<\/p>\n

    \n
  1. pozn\u00e1me IP adresu cie\u013eovej stanice<\/li>\n
  2. do hlavi\u010dky IP paketu sa vlo\u017e\u00ed na\u0161a IP adresa (zdrojov\u00e1) a cie\u013eov\u00e1 IP adresa<\/li>\n
  3. teraz potrebujeme MAC adresu cie\u013eovej stanice, bu\u010f ju m\u00e1me v ARP tabu\u013eke, alebo prevedieme ARP dotaz<\/li>\n
  4. do ethernetov\u00e9ho r\u00e1mca vlo\u017e\u00edme na\u0161u MAC adresu (zdrojov\u00fa) a cie\u013eov\u00fa MAC adresu<\/li>\n<\/ol>\n

    N\u00e1sledne sa odo\u0161l\u00fa tieto d\u00e1ta do siete (vyu\u017eije sa CSMA\/CD). Na zdie\u013eanom m\u00e9diu prejde r\u00e1mec cel\u00fa sie\u0165 a ka\u017ed\u00e1 stanica na\u010d\u00fava, \u010di neobsahuje jej MAC adresu.\u00a0Ak \u00e1no, tak r\u00e1mec prijme.<\/p>\n

    \"\"<\/p>\n

    Prepojenie pomocou switcha<\/h4>\n

    V pr\u00edpade, kedy je ethernet prepojen\u00fd do topol\u00f3gie hviezda za pomoci switcha, tak sa vo v\u00e4\u010d\u0161ine pr\u00edpadov dostane komunik\u00e1cia iba ku staniciam, ktor\u00fdm je ur\u010den\u00e1 (pomocou CAM tabu\u013eky, teda ak\u00e1 MAC adresa komunikuje z ktor\u00e9ho portu, pokia\u013e nem\u00e1 z\u00e1znam, tak odo\u0161le na v\u0161etky porty mimo prich\u00e1dzaj\u00faceho). Princ\u00edp komunik\u00e1cie je v\u0161ak rovnak\u00fd ako u zdie\u013ean\u00e9ho m\u00e9di\u00e1 a switch je pre komunikuj\u00face stanice transparentn\u00fd. Tento, dnes be\u017en\u00fd sp\u00f4sob sa ozna\u010duje ako prep\u00ednan\u00fd ethernet<\/strong><\/em>\u00a0.<\/p>\n

    \"\"<\/p>\n

    Prepojenie pomocou routeru<\/h4>\n

    V tomto pr\u00edpade je ka\u017ed\u00e1 stanica v inom subnete, tak\u017ee mus\u00ed d\u00f4js\u0165 k\u00a0 nepriamemu doru\u010deniu<\/em><\/strong>\u00a0.\u00a0Router u\u017e nie je transparentn\u00fd sie\u0165ov\u00fd prvok, ale ostatn\u00e9 sie\u0165ov\u00e9 zariadenia ho musia adresova\u0165. Nasleduj\u00faci popis je v\u0161eobecn\u00fd sp\u00f4sob komunik\u00e1cie:<\/p>\n

      \n
    1. na sie\u0165ovej vrstve sa vytvor\u00ed hlavi\u010dka IP paketu, ktor\u00e1 obsahuje IP adresu zdrojovej a cie\u013eovej stanice<\/li>\n
    2. zdrojov\u00e1 stanica testuje, \u010di je cie\u013eov\u00e1 IP adresa v rovnakom subnete, teda \u010di je pre \u0148u lok\u00e1lny<\/li>\n
    3. \u010falej pokra\u010duje vrstva sie\u0165ov\u00e9ho rozhrania vytv\u00e1ran\u00edm hlavi\u010dky ethernetov\u00e9ho r\u00e1mca, vlo\u017e\u00ed svoju zdrojov\u00fa MAC adresu, cie\u013eov\u00e1 MAC adresa sa prirad\u00ed k IP adrese z ARP ke\u0161e (dotazu) a ur\u010d\u00ed sa pod\u013ea:\n
        \n
      1. pri lok\u00e1lnej komunik\u00e1cii adresou cie\u013eovej stanice<\/li>\n
      2. pokia\u013e nie je lok\u00e1lna, tak sa pozrie do routovacej tabu\u013eky a pou\u017eije adresu patri\u010dn\u00e9ho routera (\u010fal\u0161ie hop, \u010dasto sa pou\u017eije gateway)<\/li>\n<\/ol>\n<\/li>\n
      3. r\u00e1mec sa odo\u0161le do siete<\/li>\n
      4. d\u00e1ta pr\u00eddu na router, ten pod\u013ea MAC adresy pozn\u00e1, \u017ee s\u00fa ur\u010den\u00e9 jemu<\/li>\n
      5. skontroluje packet a zn\u00ed\u017ei TTL (doba \u017eivota v sieti – po\u010det hopov)<\/li>\n
      6. znovu sa vykon\u00e1va kontrola, \u010di je IP adresa lok\u00e1lne na jednom z interface a bu\u010f sa odo\u0161le \u010fal\u0161iemu routeru alebo priamo cie\u013eovej stanici<\/li>\n
      7. cie\u013eov\u00e1 stanica prijme r\u00e1mec pod\u013ea MAC adresy<\/li>\n
      8. over\u00ed ho, skontroluje IP adresu a post\u00fapi ho skrze vrstvy nahor<\/li>\n<\/ol>\n

        \"\"<\/p>\n

        \"\"<\/p>\n","protected":false},"excerpt":{"rendered":"

        Stanica na zdie\u013eanom m\u00e9diu M\u00e1me dve stanice pripojen\u00e9 na zdie\u013eanom m\u00e9diu, \u010do m\u00f4\u017ee by\u0165 napr\u00edklad star\u00e1 verzia\u00a0ethernetu\u00a0v\u00a0\u00a0topol\u00f3gii zbernice\u00a0(bus) alebo be\u017ene pou\u017e\u00edvan\u00e1\u00a0topol\u00f3gia hviezda (star), ke\u010f sa…<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":14,"menu_order":1,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"_links":{"self":[{"href":"http:\/\/tech.sosthe.sk\/index.php\/wp-json\/wp\/v2\/pages\/700"}],"collection":[{"href":"http:\/\/tech.sosthe.sk\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/tech.sosthe.sk\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/tech.sosthe.sk\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/tech.sosthe.sk\/index.php\/wp-json\/wp\/v2\/comments?post=700"}],"version-history":[{"count":2,"href":"http:\/\/tech.sosthe.sk\/index.php\/wp-json\/wp\/v2\/pages\/700\/revisions"}],"predecessor-version":[{"id":706,"href":"http:\/\/tech.sosthe.sk\/index.php\/wp-json\/wp\/v2\/pages\/700\/revisions\/706"}],"up":[{"embeddable":true,"href":"http:\/\/tech.sosthe.sk\/index.php\/wp-json\/wp\/v2\/pages\/14"}],"wp:attachment":[{"href":"http:\/\/tech.sosthe.sk\/index.php\/wp-json\/wp\/v2\/media?parent=700"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}