{"id":13946,"date":"2024-07-11T14:10:25","date_gmt":"2024-07-11T14:10:25","guid":{"rendered":"https:\/\/tech-lib.eu\/tech\/?p=13946"},"modified":"2024-07-11T14:10:25","modified_gmt":"2024-07-11T14:10:25","slug":"understanding-how-routing-protocols-work","status":"publish","type":"post","link":"https:\/\/tech-lib.eu\/tech\/understanding-how-routing-protocols-work\/","title":{"rendered":"Understanding How Routing Protocols Work"},"content":{"rendered":"
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Jak funguje sm\u011brov\u00e1n\u00ed?<\/div>\n
Sm\u011brov\u00e1n\u00ed (anglicky routing, t\u00e9\u017e routov\u00e1n\u00ed) ozna\u010duje v informatice ur\u010dov\u00e1n\u00ed cest datagram\u016f v prost\u0159ed\u00ed po\u010d\u00edta\u010dov\u00fdch s\u00edt\u00ed. Sm\u011brov\u00e1n\u00ed zaji\u0161\u0165uj\u00ed nejen routery, ale i koncov\u00e9 stanice (p\u0159i vys\u00edl\u00e1n\u00ed) a jeho \u00fakolem je doru\u010dit datagram (resp. paket) adres\u00e1tovi, pokud mo\u017eno co nejefektivn\u011bj\u0161\u00ed cestou. <\/div>\n
\n\t\t\t\t\t Dal\u0161\u00ed informace najdete na<\/span> cs.wikipedia.org<\/a>\n\t\t\t\t<\/div>\n<\/p><\/div>\n
Sm\u011brovac\u00ed protokoly jsou pro po\u010d\u00edta\u010dov\u00e9 s\u00edt\u011b nezbytn\u00e9, proto\u017ee umo\u017e\u0148uj\u00ed rychl\u00fd a efektivn\u00ed p\u0159enos datov\u00fdch paket\u016f mezi za\u0159\u00edzen\u00edmi. Vyb\u00edraj\u00ed nejefektivn\u011bj\u0161\u00ed trasu pro p\u0159enos dat a zaji\u0161\u0165uj\u00ed, aby se data dostala tam, kam pot\u0159ebuj\u00ed. V tomto \u010dl\u00e1nku se budeme zab\u00fdvat fungov\u00e1n\u00edm sm\u011brovac\u00edch protokol\u016f, platformami, na kter\u00fdch b\u011b\u017e\u00ed, a jejich v\u00fdznamem v s\u00ed\u0165ov\u00e9 komunikaci. Probereme tak\u00e9, pro\u010d je OSPF sm\u011brovac\u00ed protokol, zda je BGP sm\u011brovac\u00ed protokol a jak\u00e9 transportn\u00ed protokoly sm\u011brovac\u00ed protokoly pou\u017e\u00edvaj\u00ed. <\/p>\n
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Sm\u011brovac\u00ed protokoly funguj\u00ed tak, \u017ee p\u0159en\u00e1\u0161ej\u00ed data mezi sm\u011brova\u010di, co\u017e jim umo\u017e\u0148uje vytvo\u0159it dynamickou mapu s\u00edt\u011b a vybrat nejlep\u0161\u00ed trasu pro p\u0159enos dat. Protokoly vnit\u0159n\u00edch bran (IGP) a protokoly vn\u011bj\u0161\u00edch bran (EGP) jsou dv\u011b hlavn\u00ed skupiny, do kter\u00fdch tyto protokoly pat\u0159\u00ed. Autonomn\u00ed syst\u00e9m (AS), co\u017e je skupina vz\u00e1jemn\u011b propojen\u00fdch s\u00edt\u00ed pod centralizovan\u00fdm spr\u00e1vn\u00edm org\u00e1nem, pou\u017e\u00edv\u00e1 IGP. Naproti tomu EGP se pou\u017e\u00edvaj\u00ed k v\u00fdm\u011bn\u011b sm\u011brovac\u00edch dat mezi r\u016fzn\u00fdmi AS. Sm\u011brovac\u00ed protokoly prov\u00e1d\u011bj\u00ed sm\u011brova\u010de, co\u017e jsou s\u00ed\u0165ov\u00e1 za\u0159\u00edzen\u00ed. Tyto komponenty maj\u00ed na starosti p\u0159ij\u00edm\u00e1n\u00ed p\u0159\u00edchoz\u00edch datov\u00fdch paket\u016f, vyhled\u00e1v\u00e1n\u00ed jejich IP adres a ur\u010dov\u00e1n\u00ed nejlep\u0161\u00ed trasy pro jejich p\u0159ed\u00e1n\u00ed. Sm\u011brovac\u00ed tabulky, kter\u00e9 sm\u011brova\u010de udr\u017euj\u00ed v aktu\u00e1ln\u00edm stavu, obsahuj\u00ed podrobnosti o dostupn\u00fdch s\u00ed\u0165ov\u00fdch cest\u00e1ch a s nimi spojen\u00e9 metriky. Sm\u011brovac\u00ed protokoly hraj\u00ed p\u0159i vytv\u00e1\u0159en\u00ed a udr\u017eov\u00e1n\u00ed t\u011bchto tabulek v\u00fdznamnou roli t\u00edm, \u017ee si vym\u011b\u0148uj\u00ed sm\u011brovac\u00ed data s okoln\u00edmi sm\u011brova\u010di. <\/p>\n

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\u010casto pou\u017e\u00edvan\u00fdm sm\u011brovac\u00edm protokolem je Open Shortest Path First (OSPF), kter\u00fd pat\u0159\u00ed do t\u0159\u00eddy IGP. Protokol OSPF b\u011b\u017e\u00ed v r\u00e1mci jednoho AS a vytv\u00e1\u0159\u00ed komplexn\u00ed mapu s\u00edt\u011b pomoc\u00ed datab\u00e1ze stavu spojen\u00ed. Na z\u00e1klad\u011b faktor\u016f, jako je \u0161\u00ed\u0159ka p\u00e1sma, zpo\u017ed\u011bn\u00ed a spolehlivost, ur\u010duje nejkrat\u0161\u00ed trasu ke ka\u017ed\u00e9mu c\u00edli. Aby udr\u017eovaly sv\u00e9 datab\u00e1ze aktu\u00e1ln\u00ed a ur\u010dovaly nejefektivn\u011bj\u0161\u00ed kan\u00e1ly pro p\u0159enos dat, vym\u011b\u0148uj\u00ed si sm\u011brova\u010de OSPF ozn\u00e1men\u00ed o stavu spojen\u00ed (LSA). Mezi <\/p>\n

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EGP naopak pat\u0159\u00ed protokol BGP (Border Gateway Protocol). Na internetu se v\u011bt\u0161inou pou\u017e\u00edv\u00e1 k pos\u00edl\u00e1n\u00ed sm\u011brovac\u00edch dat mezi n\u011bkolika p\u0159idru\u017een\u00fdmi syst\u00e9my. Spr\u00e1vci s\u00edt\u00ed mohou regulovat tok provozu a zav\u00e1d\u011bt sm\u011brovac\u00ed politiky vhodn\u00e9 pro jejich pot\u0159eby d\u00edky zam\u011b\u0159en\u00ed protokolu BGP na politiky a atributy cest sp\u00ed\u0161e ne\u017e na m\u011b\u0159en\u00ed. A\u010dkoli se protokol BGP \u010dasto ozna\u010duje jako sm\u011brovac\u00ed protokol, n\u011bkte\u0159\u00ed tvrd\u00ed, \u017ee vzhledem k jeho odli\u0161n\u00fdm vlastnostem je ve skute\u010dnosti vhodn\u011bj\u0161\u00ed ozna\u010dovat jej jako protokol dosa\u017eitelnosti. <\/p>\n

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Z hlediska transportn\u00edch protokol\u016f mohou sm\u011brovac\u00ed protokoly komunikovat pomoc\u00ed protokolu TCP (Transmission Control Protocol) nebo UDP (User Datagram Protocol). Protokol TCP poskytuje spolehlivou komunikaci zalo\u017eenou na spojen\u00ed, kter\u00e1 zaru\u010duje, \u017ee v\u0161echny pakety budou p\u0159ijaty ve spr\u00e1vn\u00e9m po\u0159ad\u00ed. Naproti tomu UDP nab\u00edz\u00ed rychlej\u0161\u00ed komunikaci bez spojen\u00ed, ale nezaru\u010duje p\u0159esn\u00e9 doru\u010den\u00ed. O tom, zda se pou\u017eije protokol TCP nebo UDP, rozhoduje konkr\u00e9tn\u00ed sm\u011brovac\u00ed protokol a jeho specifikace. <\/p>\n

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Pro efektivn\u00ed s\u00ed\u0165ovou komunikaci jsou rozhoduj\u00edc\u00ed sm\u011brovac\u00ed protokoly, kter\u00e9 vyb\u00edraj\u00ed nejefektivn\u011bj\u0161\u00ed kan\u00e1ly pro p\u0159enos dat. Spolupracuj\u00ed se sm\u011brova\u010di, p\u0159en\u00e1\u0161ej\u00ed data za \u00fa\u010delem vytvo\u0159en\u00ed sch\u00e9matu s\u00edt\u011b a napln\u011bn\u00ed sm\u011brovac\u00edch tabulek. BGP je EGP pou\u017e\u00edvan\u00fd pro komunikaci mezi AS, zat\u00edmco OSPF je p\u0159\u00edkladem IGP, kter\u00fd funguje v r\u00e1mci jednoho AS. V z\u00e1vislosti na sv\u00fdch po\u017eadavc\u00edch mohou sm\u011brovac\u00ed protokoly komunikovat pomoc\u00ed protokolu TCP nebo UDP. Spr\u00e1vci s\u00edt\u00ed mus\u00ed m\u00edt z\u00e1kladn\u00ed znalosti o fungov\u00e1n\u00ed sm\u011brovac\u00edch protokol\u016f, aby mohli spr\u00e1vn\u011b vytv\u00e1\u0159et a udr\u017eovat s\u00edt\u011b.<\/p><\/div>\n

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FAQ<\/div>\n
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Jak sm\u011brova\u010de v\u011bd\u00ed, kam maj\u00ed pos\u00edlat pakety?<\/div>\n

Sm\u011brova\u010de pou\u017e\u00edvaj\u00ed sm\u011brovac\u00ed protokoly k v\u00fdb\u011bru nejefektivn\u011bj\u0161\u00ed trasy pro p\u0159enos paket\u016f ze zdroje do c\u00edle. Sm\u011brova\u010d se pod\u00edv\u00e1 na hlavi\u010dku paketu, aby ur\u010dil c\u00edlovou adresu IP, kdy\u017e k n\u011bmu paket doraz\u00ed. Dal\u0161\u00edm krokem je prozkoum\u00e1n\u00ed sm\u011brovac\u00ed tabulky, co\u017e je seznam s\u00ed\u0165ov\u00fdch adres a tras, kter\u00fdmi se k nim lze dostat. <\/p>\n

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Pro v\u00fdm\u011bnu dat a aktualizaci sm\u011brovac\u00edch tabulek sm\u011brova\u010de komunikuj\u00ed pomoc\u00ed sm\u011brovac\u00edch protokol\u016f, jako jsou RIP (Routing Information Protocol), OSPF (Open Shortest Path First) a BGP (Border Gateway Protocol). Tyto protokoly poskytuj\u00ed sm\u011brova\u010d\u016fm mo\u017enost dozv\u011bd\u011bt se o dostupn\u00fdch cest\u00e1ch, p\u0159et\u00ed\u017een\u00ed s\u00edt\u011b a dal\u0161\u00edch aspektech, kter\u00e9 ovliv\u0148uj\u00ed, kter\u00e1 cesta je pro p\u0159enos paket\u016f nejefektivn\u011bj\u0161\u00ed. <\/p>\n

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Sm\u011brova\u010d vyb\u00edr\u00e1 optim\u00e1ln\u00ed cestu pro p\u0159ed\u00e1n\u00ed paketu na z\u00e1klad\u011b \u00fadaj\u016f ve sm\u011brovac\u00ed tabulce a metrik nab\u00edzen\u00fdch sm\u011brovac\u00edm protokolem. V z\u00e1vislosti na konkr\u00e9tn\u00edm pou\u017eit\u00e9m sm\u011brovac\u00edm algoritmu bude vybran\u00e1 trasa \u010dasto ta, kter\u00e1 m\u00e1 nejkrat\u0161\u00ed vzd\u00e1lenost, nejni\u017e\u0161\u00ed n\u00e1klady nebo nejvy\u0161\u0161\u00ed rychlost. <\/p>\n

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Z\u00e1v\u011brem lze \u0159\u00edci, \u017ee sm\u011brova\u010de pou\u017e\u00edvaj\u00ed sm\u011brovac\u00ed protokoly ke komunikaci s ostatn\u00edmi sm\u011brova\u010di, aktualizuj\u00ed sv\u00e9 sm\u011brovac\u00ed tabulky a ur\u010duj\u00ed, kam maj\u00ed p\u0159en\u00e1\u0161et pakety. Tyto tabulky pom\u00e1haj\u00ed sm\u011brova\u010d\u016fm na z\u00e1klad\u011b r\u016fzn\u00fdch krit\u00e9ri\u00ed, v\u010detn\u011b vzd\u00e1lenosti, n\u00e1klad\u016f a rychlosti, vybrat nejv\u00fdhodn\u011bj\u0161\u00ed cestu pro p\u0159ed\u00e1n\u00ed paket\u016f. <\/p>\n<\/div>\n

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Pro\u010d je protokol OSPF lep\u0161\u00ed ne\u017e protokol BGP?<\/div>\n

V po\u010d\u00edta\u010dov\u00fdch s\u00edt\u00edch existuj\u00ed dva b\u011b\u017en\u00e9 sm\u011brovac\u00ed protokoly: OSPF (Open Shortest Path First) a BGP (Border Gateway Protocol), jejich pou\u017eit\u00ed a v\u00fdhody se v\u0161ak li\u0161\u00ed. Zat\u00edmco protokol BGP se obvykle pou\u017e\u00edv\u00e1 ke komunikaci sm\u011brovac\u00edch dat mezi r\u016fzn\u00fdmi autonomn\u00edmi syst\u00e9my (AS) v internetu, protokol OSPF se obvykle pou\u017e\u00edv\u00e1 v r\u00e1mci vnit\u0159n\u00ed s\u00edt\u011b organizace. <\/p>\n

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Za ur\u010dit\u00fdch okolnost\u00ed je protokol OSPF up\u0159ednost\u0148ov\u00e1n p\u0159ed protokolem BGP kv\u016fli rychlej\u0161\u00ed konvergenci. Term\u00edn „doba konvergence“ popisuje, jak rychle se s\u00ed\u0165 dok\u00e1\u017ee p\u0159izp\u016fsobit zm\u011bn\u00e1m ve sv\u00e9 topologii nebo sm\u011brovac\u00edch informac\u00edch. D\u00edky pou\u017eit\u00ed algoritmu sm\u011brov\u00e1n\u00ed ve stavu spojen\u00ed, kter\u00fd umo\u017e\u0148uje sm\u011brova\u010d\u016fm sd\u00edlet informace o sv\u00fdch p\u0159\u00edmo propojen\u00fdch link\u00e1ch, m\u00e1 protokol OSPF rychlej\u0161\u00ed dobu konvergence. V d\u016fsledku toho m\u016f\u017ee protokol OSPF aktualizovat sm\u011brovac\u00ed tabulku a rychle ur\u010dit nejkrat\u0161\u00ed cestu k c\u00edli. <\/p>\n

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Vlastnostem cesty a z\u00e1sad\u00e1m spojen\u00fdm s r\u016fzn\u00fdmi trasami je naopak v\u011bnov\u00e1na v\u011bt\u0161\u00ed pozornost ve sm\u011brovac\u00edm algoritmu path-vector, kter\u00fd pou\u017e\u00edv\u00e1 protokol BGP. \u0160k\u00e1lovatelnost a slo\u017eitost internetu, kde jsou rozhodnut\u00ed o sm\u011brov\u00e1n\u00ed zalo\u017eena na \u0159ad\u011b prom\u011bnn\u00fdch v\u010detn\u011b s\u00ed\u0165ov\u00fdch politik, dopravn\u00edho in\u017een\u00fdrstv\u00ed a po\u017eadavk\u016f na v\u00fdkon, je n\u011bco, co je c\u00edlem protokolu BGP. V\u00fdhodou protokolu BGP je, \u017ee dok\u00e1\u017ee spravovat rozs\u00e1hl\u00e9 s\u00edt\u011b a nab\u00edz\u00ed v\u011bt\u0161\u00ed kontrolu a flexibilitu p\u0159i v\u00fdb\u011bru tras. <\/p>\n

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Z\u00e1v\u011brem lze \u0159\u00edci, \u017ee protokol OSPF je obvykle up\u0159ednost\u0148ov\u00e1n p\u0159ed protokolem BGP, proto\u017ee dosahuje krat\u0161\u00ed doby konvergence vnit\u0159n\u00ed s\u00edt\u011b. P\u0159esto\u017ee protokol BGP nab\u00edz\u00ed v\u011bt\u0161\u00ed kontrolu a flexibilitu p\u0159i v\u00fdb\u011bru tras, vynik\u00e1 p\u0159i \u0159e\u0161en\u00ed probl\u00e9m\u016f spojen\u00fdch s propojen\u00edm nez\u00e1visl\u00fdch syst\u00e9m\u016f p\u0159es internet. O tom, zda se m\u00e1 pou\u017e\u00edt protokol OSPF nebo BGP, rozhoduj\u00ed p\u0159esn\u00e9 pot\u0159eby a vlastnosti nasazovan\u00e9 s\u00edt\u011b.<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Jak funguje sm\u011brov\u00e1n\u00ed? Sm\u011brov\u00e1n\u00ed (anglicky routing, t\u00e9\u017e routov\u00e1n\u00ed) ozna\u010duje v informatice ur\u010dov\u00e1n\u00ed cest datagram\u016f v prost\u0159ed\u00ed po\u010d\u00edta\u010dov\u00fdch s\u00edt\u00ed. Sm\u011brov\u00e1n\u00ed zaji\u0161\u0165uj\u00ed nejen routery, ale i koncov\u00e9 stanice (p\u0159i vys\u00edl\u00e1n\u00ed) a jeho \u00fakolem je doru\u010dit datagram (resp. paket) adres\u00e1tovi, pokud mo\u017eno co nejefektivn\u011bj\u0161\u00ed cestou. Dal\u0161\u00ed informace najdete na cs.wikipedia.org Sm\u011brovac\u00ed protokoly jsou pro po\u010d\u00edta\u010dov\u00e9 s\u00edt\u011b nezbytn\u00e9, proto\u017ee … \u010c\u00edst d\u00e1l<\/a><\/p>\n","protected":false},"author":676,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[33],"tags":[],"class_list":["post-13946","post","type-post","status-publish","format-standard","hentry","category-networking"],"_links":{"self":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/posts\/13946","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/users\/676"}],"replies":[{"embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/comments?post=13946"}],"version-history":[{"count":1,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/posts\/13946\/revisions"}],"predecessor-version":[{"id":16185,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/posts\/13946\/revisions\/16185"}],"wp:attachment":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/media?parent=13946"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/categories?post=13946"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/tags?post=13946"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}