{"id":4172,"date":"2023-08-25T00:00:00","date_gmt":"2023-08-25T00:00:00","guid":{"rendered":"https:\/\/tech-lib.eu\/tech\/porozumeni-fungovani-podsiti-a-comprehensive-guide\/"},"modified":"2023-08-25T00:00:00","modified_gmt":"2023-08-25T00:00:00","slug":"porozumeni-fungovani-podsiti-a-comprehensive-guide","status":"publish","type":"post","link":"https:\/\/tech-lib.eu\/tech\/porozumeni-fungovani-podsiti-a-comprehensive-guide\/","title":{"rendered":"Porozum\u011bn\u00ed fungov\u00e1n\u00ed pods\u00edt\u00ed. A Comprehensive Guide"},"content":{"rendered":"
\n
Jak funguje maska pods\u00edt\u011b?<\/div>\n
Maska pods\u00edt\u011b "maskuje" \u010d\u00e1st hostitelsk\u00e9 adresy IP spolu s celou s\u00ed\u0165ovou \u010d\u00e1st\u00ed adresy jedni\u010dkami a nech\u00e1v\u00e1 ve zb\u00fdvaj\u00edc\u00ed \u010d\u00e1sti nuly, kter\u00e9 jsou k dispozici pro adresov\u00e1n\u00ed hostitel\u016f. V\u011bt\u0161inou v masce nastavujeme a\u017e posledn\u00ed hodnotu (za posledn\u00ed te\u010dkou, tj. 255.255.255. Cached<\/div>\n
\n\t\t\t\t\t Dal\u0161\u00ed informace najdete na<\/span> www.elsaco.cz<\/a>\n\t\t\t\t<\/div>\n<\/p><\/div>\n
\n
<\/div>\n

Pods\u00edt\u011b jsou kl\u00ed\u010dovou my\u0161lenkou v po\u010d\u00edta\u010dov\u00fdch s\u00edt\u00edch a umo\u017e\u0148uj\u00ed efektivn\u00ed spr\u00e1vu a komunikaci uvnit\u0159 v\u011bt\u0161\u00edch s\u00edt\u00ed. Jsou nezbytn\u00e9 pro rozd\u011blen\u00ed s\u00edt\u011b na men\u0161\u00ed, sn\u00e1ze spravovateln\u00e9 jednotky a umo\u017e\u0148uj\u00ed za\u0159\u00edzen\u00edm uvnit\u0159 t\u011bchto jednotek vz\u00e1jemn\u00e9 propojen\u00ed. V tomto p\u0159\u00edsp\u011bvku se budeme zab\u00fdvat fungov\u00e1n\u00edm pods\u00edt\u00ed, jejich vz\u00e1jemnou komunikac\u00ed, v\u00fdznamem masky pods\u00edt\u011b a b\u011b\u017en\u00fdmi myln\u00fdmi p\u0159edstavami o hodnot\u00e1ch pods\u00edt\u00ed. <\/p>\n

<\/div>\n

V\u011bt\u0161\u00ed s\u00ed\u0165 je rozd\u011blena na men\u0161\u00ed logick\u00e9 s\u00edt\u011b, kter\u00e9 tvo\u0159\u00ed pods\u00edt\u011b, zn\u00e1m\u00e9 tak\u00e9 jako pods\u00edt\u011b. K tomuto rozd\u011blen\u00ed se pou\u017e\u00edv\u00e1 maska pods\u00edt\u011b, 32bitov\u00e1 hodnota slou\u017e\u00edc\u00ed k odd\u011blen\u00ed s\u00ed\u0165ov\u00e9 \u010d\u00e1sti od hostitelsk\u00e9 \u010d\u00e1sti adresy IP. Maska pods\u00edt\u011b funguje jako filtr, kter\u00fd ur\u010duje, kter\u00e1 \u010d\u00e1st adresy IP pat\u0159\u00ed s\u00edti a kter\u00e1 hostiteli. B\u011b\u017en\u011b se zapisuje v des\u00edtkov\u00e9 notaci takto: 255.255.255.0. <\/p>\n

<\/div>\n

Pod\u00edvejme se na p\u0159\u00edklad, abychom l\u00e9pe pochopili, jak pods\u00edt\u011b funguj\u00ed. \u0158ekn\u011bme, \u017ee m\u00e1me s\u00ed\u0165 s rozsahem adres IP 192.168.1.0\/24. P\u00edsmeno \/24 znamen\u00e1, \u017ee s\u00ed\u0165ov\u00e1 \u010d\u00e1st adresy IP zabere prvn\u00edch 24 bit\u016f a zb\u00fdvaj\u00edc\u00edch 8 bit\u016f z\u016fstane voln\u00fdch pro adresy hostitel\u016f. V tomto p\u0159\u00edpad\u011b by maska pods\u00edt\u011b byla 255.255.255.0, co\u017e znamen\u00e1, \u017ee posledn\u00edch osm bit\u016f adresy IP ozna\u010duje hostitele a prvn\u00ed t\u0159i oktety (24 bit\u016f) adresy IP p\u0159edstavuj\u00ed s\u00ed\u0165. <\/p>\n

<\/div>\n

Pods\u00edt\u011b pou\u017e\u00edvaj\u00ed ke vz\u00e1jemn\u00e9 komunikaci sm\u011brova\u010de. Sm\u011brova\u010de jsou komponenty, kter\u00e9 propojuj\u00ed r\u016fzn\u00e9 pods\u00edt\u011b a umo\u017e\u0148uj\u00ed p\u0159enos datov\u00fdch paket\u016f mezi nimi. Za\u0159\u00edzen\u00ed uvnit\u0159 pods\u00edt\u011b ode\u0161le datov\u00fd paket sm\u011brova\u010di p\u0159i\u0159azen\u00e9mu k jeho pods\u00edti, kdy\u017e pot\u0159ebuje komunikovat se za\u0159\u00edzen\u00edm v jin\u00e9 pods\u00edti. Sm\u011brova\u010d se pod\u00edv\u00e1 na c\u00edlovou IP adresu paketu, aby ur\u010dil spr\u00e1vnou pods\u00ed\u0165, a pak p\u0159ed\u00e1 paket do t\u00e9to pods\u00edt\u011b. Za\u0159\u00edzen\u00ed v r\u016fzn\u00fdch pods\u00edt\u00edch v\u011bt\u0161\u00ed s\u00edt\u011b mohou d\u00edky t\u00e9to technice mezi sebou neviditeln\u011b komunikovat. <\/p>\n

<\/div>\n

Vyvra\u0165me nyn\u00ed m\u00fdtus, \u017ee pods\u00edt\u011b jsou v\u017edy reprezentov\u00e1ny \u010d\u00edslem 255. A\u010dkoli se \u010d\u00edsla 255 v masce pods\u00edt\u011b \u010dasto pou\u017e\u00edvaj\u00ed, nen\u00ed to nutn\u00e9. Pokud jsou s\u00ed\u0165ov\u00e1 a hostitelsk\u00e1 \u010d\u00e1st adresy IP p\u0159esn\u011b definov\u00e1ny, m\u016f\u017ee m\u00edt maska pods\u00edt\u011b libovolnou hodnotu. Nap\u0159\u00edklad maska pods\u00edt\u011b 255.255.255.192 by rozd\u011blila adresu IP na \u010dty\u0159i pods\u00edt\u011b, z nich\u017e ka\u017ed\u00e1 by mohla obsahovat 62 hostitel\u016f. V\u00fdb\u011br masky pods\u00edt\u011b je zalo\u017een na konkr\u00e9tn\u00edch po\u017eadavc\u00edch s\u00edt\u011b a tak\u00e9 na p\u0159edpokl\u00e1dan\u00e9m po\u010dtu hostitel\u016f v ka\u017ed\u00e9 pods\u00edti. <\/p>\n

<\/div>\n

Nakonec se v\u011bnujme nejasnostem kolem hodnoty 255.255.0.0, kter\u00e1 ozna\u010duje pods\u00ed\u0165 s kapacitou 16. 255.255.0.0 je platn\u00e1 maska pods\u00edt\u011b, ale neodpov\u00edd\u00e1 pods\u00edti s velikost\u00ed 16. V p\u0159\u00edpad\u011b, \u017ee se jedn\u00e1 o pods\u00ed\u0165 s kapacitou 16, je mo\u017en\u00e9, \u017ee se jedn\u00e1 o masku pods\u00edt\u011b. M\u00edsto toho ozna\u010duje pods\u00ed\u0165 o velikosti 16 384 (256 x 256). V tomto p\u0159\u00edpad\u011b m\u016f\u017ee ka\u017ed\u00e1 pods\u00ed\u0165 podporovat a\u017e 65 534 hostitel\u016f. Po\u010det dostupn\u00fdch hostitelsk\u00fdch adres v \u010d\u00e1sti hostitele masky pods\u00edt\u011b ur\u010duje velikost pods\u00edt\u011b. <\/p>\n

<\/div>\n

Pods\u00edt\u011b, kter\u00e9 rozd\u011bluj\u00ed v\u011bt\u0161\u00ed s\u00ed\u0165 na men\u0161\u00ed logick\u00e9 s\u00edt\u011b, umo\u017e\u0148uj\u00ed efektivn\u00ed spr\u00e1vu s\u00edt\u011b. Maska pods\u00edt\u011b je kl\u00ed\u010dovou sou\u010d\u00e1st\u00ed p\u0159i ur\u010dov\u00e1n\u00ed s\u00ed\u0165ov\u00e9 a hostitelsk\u00e9 \u010d\u00e1sti adresy IP a pods\u00edt\u011b spolu komunikuj\u00ed prost\u0159ednictv\u00edm sm\u011brova\u010d\u016f. A\u010dkoli se v mask\u00e1ch pods\u00edt\u00ed \u010dasto pou\u017e\u00edv\u00e1 \u010d\u00edslo 255, nen\u00ed to nezbytn\u00e9 a v\u00fdb\u011br masky pods\u00edt\u011b z\u00e1vis\u00ed na konkr\u00e9tn\u00edch po\u017eadavc\u00edch s\u00edt\u011b. Pro konstrukci a spr\u00e1vu spolehliv\u00fdch a \u0161k\u00e1lovateln\u00fdch s\u00edt\u00ed je nezbytn\u00e9 pochopit, jak pods\u00edt\u011b funguj\u00ed.<\/p><\/div>\n

\n
FAQ<\/div>\n
\n
Co kdybyste m\u011bli masku pods\u00edt\u011b 255.255 255.0?<\/div>\n

Prvn\u00ed t\u0159i oktety adresy IP tvo\u0159\u00ed s\u00ed\u0165ovou \u010d\u00e1st a posledn\u00ed oktet slou\u017e\u00ed k identifikaci hostitel\u016f v t\u00e9to s\u00edti, za p\u0159edpokladu, \u017ee va\u0161e maska pods\u00edt\u011b byla 255.255.255.0. To znamen\u00e1, \u017ee se v s\u00edti vyskytuje pouze jeden oktet. <\/p>\n

<\/div>\n

V tomto p\u0159\u00edpad\u011b maska pods\u00edt\u011b 255.255.255.0 umo\u017e\u0148uje v r\u00e1mci t\u00e9to s\u00edt\u011b p\u0159id\u011blit a\u017e 256 adres IP. Rozsah p\u0159id\u011blen\u00fdch IP adres (s v\u00fdjimkou s\u00ed\u0165ov\u00fdch a vys\u00edlac\u00edch adres) by byl 0 a\u017e 255. <\/p>\n

<\/div>\n

Aby bylo jasno, s\u00ed\u0165ov\u00e1 adresa by byla adresa IP se v\u0161emi bity hostitele nastaven\u00fdmi na 0, co\u017e by v tomto p\u0159\u00edpad\u011b byly prvn\u00ed t\u0159i oktety n\u00e1sledovan\u00e9 0 (nap\u0159\u00edklad 192.168.1.0). Naproti tomu broadcastov\u00e1 adresa by se skl\u00e1dala z prvn\u00edch t\u0159\u00ed oktet\u016f n\u00e1sledovan\u00fdch \u010d\u00edslem 255 (nap\u0159\u00edklad 192.168.1.255), p\u0159i\u010dem\u017e v\u0161echny hostitelsk\u00e9 bity by byly nastaveny na 1. <\/p>\n

<\/div>\n

V\u00fdsledkem je, \u017ee pokud by maska pods\u00edt\u011b va\u0161\u00ed s\u00edt\u011b byla 255.255.255.0, m\u011bli byste k dispozici 256 IP adres, kter\u00e9 by bylo mo\u017en\u00e9 p\u0159id\u011blit, v rozsahu od 192.168.1.1 do 192.168.1.254. <\/p>\n<\/div>\n

\n
Na jak\u00e9 pods\u00edt\u011b se d\u011bl\u00ed 255.255 255.0?<\/div>\n

Drobn\u00e9 pods\u00edt\u011b, kter\u00e9 tvo\u0159\u00ed pods\u00ed\u0165 255.255.255.0, jsou n\u00e1sleduj\u00edc\u00ed: <\/p>\n

<\/div>\n

– S\u00ed\u0165 t\u0159\u00eddy C je reprezentov\u00e1na 255.255.255.0 (zn\u00e1m\u00e1 tak\u00e9 jako pods\u00ed\u0165 \/24), kde je posledn\u00ed oktet (0) vyu\u017eit pro adresy hostitel\u016f a prvn\u00ed t\u0159i oktety (255.255.255) jsou pevn\u00e9. K t\u00e9to pods\u00edti m\u016f\u017ee b\u00fdt p\u0159ipojeno a\u017e 254 hostitel\u016f. <\/p>\n

<\/div>\n

Dejte mi pros\u00edm v\u011bd\u011bt, pokud budete pot\u0159ebovat dal\u0161\u00ed \u010dlen\u011bn\u00ed nebo budete m\u00edt dal\u0161\u00ed dotazy. <\/p>\n<\/div>\n

\n
Mohou m\u00edt 2 pods\u00edt\u011b stejnou IP adresu?<\/div>\n

Stejn\u00e1 IP adresa nem\u016f\u017ee existovat ve dvou pods\u00edt\u00edch. Pods\u00edt\u011b jsou logick\u00fdm rozd\u011blen\u00edm v\u011bt\u0161\u00ed s\u00edt\u011b IP a ka\u017ed\u00e1 pods\u00ed\u0165 m\u00e1 vlastn\u00ed odli\u0161nou sadu adres IP, kter\u00e9 slou\u017e\u00ed jako identifik\u00e1tor. Aby byla zaru\u010dena spr\u00e1vn\u00e1 komunikace a sm\u011brov\u00e1n\u00ed mezi za\u0159\u00edzen\u00edmi v r\u00e1mci pods\u00edt\u011b, mus\u00ed b\u00fdt adresy IP uvnit\u0159 t\u00e9to pods\u00edt\u011b odli\u0161n\u00e9. Pokud by dv\u011b pods\u00edt\u011b sd\u00edlely stejnou adresu IP, vznikly by konflikty a probl\u00e9my s komunikac\u00ed.<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Jak funguje maska pods\u00edt\u011b? Maska pods\u00edt\u011b "maskuje" \u010d\u00e1st hostitelsk\u00e9 adresy IP spolu s celou s\u00ed\u0165ovou \u010d\u00e1st\u00ed adresy jedni\u010dkami a nech\u00e1v\u00e1 ve zb\u00fdvaj\u00edc\u00ed \u010d\u00e1sti nuly, kter\u00e9 jsou k dispozici pro adresov\u00e1n\u00ed hostitel\u016f. V\u011bt\u0161inou v masce nastavujeme a\u017e posledn\u00ed hodnotu (za posledn\u00ed te\u010dkou, tj. 255.255.255. Cached Dal\u0161\u00ed informace najdete na www.elsaco.cz Pods\u00edt\u011b jsou kl\u00ed\u010dovou my\u0161lenkou v po\u010d\u00edta\u010dov\u00fdch … \u010c\u00edst d\u00e1l<\/a><\/p>\n","protected":false},"author":2826,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[33],"tags":[],"class_list":["post-4172","post","type-post","status-publish","format-standard","hentry","category-networking"],"_links":{"self":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/posts\/4172","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\/2826"}],"replies":[{"embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/comments?post=4172"}],"version-history":[{"count":0,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/posts\/4172\/revisions"}],"wp:attachment":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/media?parent=4172"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/categories?post=4172"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/tags?post=4172"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}