{"id":494,"date":"2020-04-06T20:26:59","date_gmt":"2020-04-06T18:26:59","guid":{"rendered":"http:\/\/tech.sosthe.sk\/?page_id=494"},"modified":"2020-04-06T20:26:59","modified_gmt":"2020-04-06T18:26:59","slug":"10-rapid-spanning-tree-protocol","status":"publish","type":"page","link":"http:\/\/tech.sosthe.sk\/index.php\/ccna\/cisco-ios\/10-rapid-spanning-tree-protocol\/","title":{"rendered":"10. Rapid Spanning Tree Protocol"},"content":{"rendered":"

Rapid Spanning Tree Protocol (RSTP)<\/span><\/h3>\n

Maxim\u00e1lny \u010das, kedy konverguje STP je 50s (v praxi m\u00f4\u017eeme dosiahnu\u0165 ni\u017e\u0161ie hodnoty, ale tak okolo 30s), \u010do je pre praktick\u00e9 situ\u00e1cie pr\u00edli\u0161 vysok\u00e1 hodnota.\u00a0Preto bol vymyslen\u00fd upraven\u00fd algoritmus zvan\u00fd\u00a0<\/span>Rapid Spanning Tree Protocol<\/span><\/em><\/strong>\u00a0(RSTP), ktor\u00fd m\u00e1 \u010das konvergencie v praxi okolo 1 \u010di 2s.\u00a0RSTP bol p\u00f4vodne definovan\u00fd ako roz\u0161\u00edrenie normou IEEE 802.1w, ale v roku 2004 bol zaraden\u00fd do normy IEEE 802.1D.<\/span><\/p>\n

Z\u00e1kladn\u00fd princ\u00edp je podobn\u00fd klasick\u00e9mu STP, ale je upraven\u00fd pre r\u00fdchlej\u0161ie konvergenciu pri zmene topol\u00f3giu.\u00a0M\u00e1 integrovan\u00fd ekvivalent Cisco funkci\u00ed\u00a0<\/span>PortFast<\/span><\/em>\u00a0,\u00a0<\/span>UplinkFast<\/span><\/em>\u00a0a\u00a0<\/span>BackboneFast<\/span><\/em>\u00a0.<\/span><\/p>\n

Pozn .:<\/span><\/em><\/strong>\u00a0RSTP je sp\u00e4tne kompatibiln\u00fd s klasick\u00fdm STP.\u00a0Ale ak detekuje nejak\u00fd BPDU r\u00e1mec z STP, tak sa prepne do tohto m\u00f3du.<\/span><\/p>\n

Zmeny oproti STP<\/span><\/h4>\n
    \n
  • drobn\u00e1 zmena form\u00e1tu BPDU (pou\u017e\u00edva sa verzia 2)<\/span><\/li>\n
  • v\u0161etky switche generuj\u00fa BPDU a posielaj\u00fa ich na v\u0161etky porty ka\u017ed\u00fd hello time (miesto preposielanie Root BPDU)<\/span><\/li>\n
  • posielaj\u00fa sa Agreement \/ Proposal BPDU<\/span><\/li>\n
  • pre linky sa definuje ich typ (point-to-point, edge, shared), tak\u017ee niektor\u00e9 m\u00f4\u017eu r\u00fdchlo prejs\u0165 do stavu\u00a0<\/span>forwarding<\/span><\/em><\/li>\n
  • zmenili sa \u00falohy \/ typy portov, s\u00fa \u0161tyri (root, designated, alternate, backup)<\/span><\/li>\n
  • stavy portov (Discarding, learning, forwarding)<\/span><\/li>\n<\/ul>\n

    Typy portov \/ liniek<\/span><\/h4>\n
      \n
    • point-to-point<\/span><\/strong>\u00a0, teda spoj bod-bod, pripojenie \u010fal\u0161ieho switche, linka mus\u00ed by\u0165 full duplex<\/span><\/li>\n
    • edge<\/span><\/strong>\u00a0, koncov\u00fd \/ hrani\u010dn\u00e9 port (PortFast), je do neho pripojen\u00e9 koncov\u00e9 zariadenia (ako PC \u010di tla\u010diare\u0148)<\/span><\/li>\n
    • shared<\/span><\/strong>\u00a0, zdie\u013ean\u00e1 linka, napr\u00edklad h\u00fab, linka je half duplex<\/span><\/li>\n<\/ul>\n

      Edge porty<\/span><\/em><\/strong>\u00a0definujeme pomocou funkcie<\/span>\u00a0PortFast<\/span><\/em>\u00a0.\u00a0<\/span>Point-to-point<\/span><\/em><\/strong>\u00a0a<\/span>\u00a0shared<\/span><\/em><\/strong>\u00a0konfigurujeme pomocou<\/span>\u00a0link-type<\/span><\/em>\u00a0.\u00a0Predvolen\u00fd stav pre full duplex linky je<\/span>\u00a0P2P.\u00a0<\/span><\/em><\/strong>Pre P2P mus\u00edme zaru\u010di\u0165, aby bola linka vo full duplex m\u00f3du.<\/span><\/p>\n

      \u00daloha portov<\/span><\/h4>\n
        \n
      • Root Port<\/span><\/strong>\u00a0– najlep\u0161ie BPDU na switchi<\/span><\/li>\n
      • Designated Port<\/span><\/strong>\u00a0– najlep\u0161ie BPDU na segmente<\/span><\/li>\n
      • Alternate Port<\/span><\/strong>\u00a0– blokovan\u00fd, alternat\u00edvna cesta k roote (z\u00e1loha root)<\/span><\/li>\n
      • Backup Port<\/span><\/strong>\u00a0– blokovan\u00fd, redundantn\u00e9 cesta k segmentu (z\u00e1loha designated)<\/span><\/li>\n<\/ul>\n

        BPDU<\/span><\/h4>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
        ve\u013ekos\u0165 [B]<\/span><\/td>\npolo\u017eka<\/span><\/td>\n<\/tr>\n
        2<\/span><\/td>\nprotokol ID<\/span><\/td>\n<\/tr>\n
        2<\/span><\/td>\nverzia protokolu<\/span><\/td>\n<\/tr>\n
        2<\/span><\/td>\ntyp BPDU<\/span><\/td>\n<\/tr>\n
        1<\/span><\/td>\npr\u00edznaky<\/span><\/td>\n<\/tr>\n
        8<\/span><\/td>\nroot BID<\/span><\/td>\n<\/tr>\n
        4<\/span><\/td>\ncena cesty k rootu<\/span><\/td>\n<\/tr>\n
        8<\/span><\/td>\nodosielate\u013eovou BID<\/span><\/td>\n<\/tr>\n
        2<\/span><\/td>\nID portu, ktor\u00fd posiela BPDU<\/span><\/td>\n<\/tr>\n
        2<\/span><\/td>\nMessage Age<\/span><\/td>\n<\/tr>\n
        2<\/span><\/td>\nmaximum Age<\/span><\/td>\n<\/tr>\n
        2<\/span><\/td>\nHello Time<\/span><\/td>\n<\/tr>\n
        2<\/span><\/td>\nforward Delay<\/span><\/td>\n<\/tr>\n
        1<\/span><\/td>\nVerison 1 length<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

        Pozn .:<\/span><\/em><\/strong>\u00a0Switch, na ktorom be\u017e\u00ed klasick\u00fd STP, zahadzuje BPDU z RSTP.<\/span><\/p>\n

        V\u0161etky switche posielaj\u00fa BPDU ka\u017ed\u00fd hello time, u STP sa preposielaj\u00fa \/ modifikuj\u00fa BPDU prijat\u00e9 na Root Porte.\u00a0Message Age sl\u00fa\u017ei ako po\u010d\u00edtadlo hopu, po vy\u010derpan\u00ed je r\u00e1mec zahoden\u00fd.<\/span><\/p>\n

        Agreement \/ proposal<\/span><\/h4>\n

        Ponuka a s\u00fahlas.\u00a0Switche posielaj\u00fa ponuku susedovi, ak m\u00e1 sused v\u00e4\u010d\u0161iu BID, tak odpovie s\u00fahlasom a obaja prednastav\u00ed stav (root a designed).<\/span><\/p>\n

        Konfigur\u00e1cia RSTP na Cisco IOSu<\/span><\/h3>\n

        Na Cisco switchoch be\u017e\u00ed upraven\u00e1 verzia RSTP protokolu ozna\u010dovan\u00e1 ako\u00a0<\/span>Rapid PVSTP +<\/span><\/em><\/strong>\u00a0(pou\u017e\u00edva sa skratka RPVSTP \u010di PVRSTP \u010di rapid-PVSTP), ke\u010f pre ka\u017ed\u00fa VLAN be\u017e\u00ed samostatn\u00e1 in\u0161tancie STP.<\/span><\/p>\n

        Be\u017en\u00fd, a asi jedin\u00fd mo\u017en\u00fd, postup konfigur\u00e1cie spo\u010d\u00edva v tom, \u017ee sa najprv nakonfiguruje\u00a0<\/span>PVSTP +<\/span><\/em><\/strong>\u00a0(ten be\u017e\u00ed defaultne) a potom sa prejde do m\u00f3du\u00a0<\/span>RPVSTP +<\/span><\/em><\/strong>\u00a0.\u00a0Prechod m\u00f4\u017ee by\u0165 postupn\u00fd (asi nedok\u00e1\u017eeme nakonfigurova\u0165 v\u0161etky switche naraz), preto\u017ee RSTP je sp\u00e4tne kompatibiln\u00fd s STP.\u00a0Je d\u00f4le\u017eit\u00e9 pam\u00e4ta\u0165 na to, \u017ee pri prechode d\u00f4jde k v\u00fdpadkom spojenia.<\/span><\/p>\n

        V rapid-Pin neexistuj\u00fa funkcie\u00a0<\/span>UplinkFast<\/span><\/strong><\/em>\u00a0a\u00a0<\/span>BackboneFast<\/span><\/strong><\/em>\u00a0, ak sa prepneme do RSTP, tak sa tieto funkcie neuplatnia, napriek tomu sa odpor\u00fa\u010da je vypn\u00fa\u0165.<\/span><\/p>\n

        SWITCH (config) # no spanning-tree uplinkfast<\/strong> \r\nSWITCH (config) # no spanning-tree backbonefast<\/strong><\/span><\/pre>\n
        Pre prechod z Pin m\u00f3du do rapid Pin sta\u010d\u00ed jedin\u00fd pr\u00edkaz.<\/span><\/p>\n
        SWITCH (config) # spanning-tree mode rapid-Pin<\/strong><\/span><\/pre>\n
        Ur\u010dovanie typu linky sa vykon\u00e1va na jednotliv\u00fdch portoch<\/span><\/p>\n
        SWITCH (config-if) # spanning-tree portfast                  <\/strong>\/\/ m\u00f3d portu edge \r\nSWITCH (config-if) # spanning-tree portfast trunk            <\/strong>\/\/ ak je port trunk a chceme ho nastavi\u0165 ako edge \r\nSWITCH (config-if) # spanning-tree link-type point-to-point <\/strong>\/\/ m\u00f3d portu P2P \r\nSWITCH (config-if) # spanning-tree link-type shared          <\/strong>\/\/ m\u00f3d shared<\/span><\/pre>\n
        Po tom, \u010do nastav\u00edme v\u0161etky switche do RPVST, tak bud\u00fa pracova\u0165 st\u00e1le v m\u00f3de Pin, preto\u017ee migra\u010dn\u00fd proces zist\u00ed, \u017ee sused je v m\u00f3de Pin a kv\u00f4li kompatibilite sa neprepne.\u00a0Switch nespozn\u00e1, \u017ee sa u\u017e m\u00f4\u017ee prepn\u00fa\u0165 do RPVST, mus\u00edme vyvola\u0165 znova vyjedn\u00e1vanie o protokole.\u00a0Nasleduj\u00faci pr\u00edkaz re\u0161tartuje migra\u010dn\u00fd proces.<\/span><\/p>\n
        SWITCH # clear spanning-tree detected-protocols<\/strong><\/span><\/pre>\n
        Pozn\u00e1mky z praktick\u00e9ho nasadenia RSTP<\/span><\/h4>\n
        Uvediem p\u00e1r praktick\u00fdch pozn\u00e1mok, ke\u010f som prech\u00e1dzal z\u00a0<\/span>PVSTP +<\/span><\/strong><\/em>\u00a0na\u00a0<\/span>Rapid PVSTP +<\/span><\/strong><\/em>\u00a0na asi 13 Cisco switchoch.\u00a0V tejto sieti nie s\u00fa \u017eiadne \u00famyseln\u00e9 slu\u010dky a STP sa pou\u017e\u00edva jednoducho, ak by omylom vznikla slu\u010dka.<\/span><\/p>\n
        Najviac ma zauj\u00edmalo, ako vlastne bude prebieha\u0165 cel\u00fd prechod (kedy k nemu d\u00f4jde) a ak\u00e9 bud\u00fa v\u00fdpadky.\u00a0Presn\u00e9 odpovede som nikde na nete nena\u0161iel (ani v Cisco \u010dl\u00e1nku, ktor\u00fd opisuje t\u00fato migr\u00e1ciu).\u00a0Vo v\u0161etk\u00fdch inform\u00e1ci\u00e1ch sa zd\u00f4raz\u0148uje, \u017ee pri prechode d\u00f4jde k v\u00fdpadkom.\u00a0A tie\u017e sa zd\u00f4raz\u0148uje, \u017ee ak switch v RSTP detekuje BPDU z STP, tak sa prepne do STP (mysl\u00edm Cisco verzia) a u\u017e sa nedok\u00e1\u017ee prepn\u00fa\u0165 sp\u00e4\u0165 do RSTP.\u00a0Pre prepnutie potom mus\u00edme vyu\u017ei\u0165 vy\u0161\u0161ie uveden\u00fd pr\u00edkaz.\u00a0Preto ma nebolo jasn\u00e9, ke\u010f postupne prepnem switche do RSTP, ako vyvola\u0165 nov\u00e9 vyjedn\u00e1vanie na v\u0161etk\u00fdch naraz.\u00a0No v praxi to vyzeralo n\u00e1sledne.<\/span><\/p>\n
        Na za\u010diatku som mal na v\u0161etk\u00fdch switchoch koncovej porty nakonfigurovan\u00e9 pomocou\u00a0<\/span>PortFast<\/code>.\u00a0P\u0159ekonfiguraci switchov som za\u010dal na\u00a0<\/span>access switchoch<\/span><\/strong><\/em>\u00a0(nie od jadra, ako sa odpor\u00fa\u010da u MST).\u00a0V\u00e4\u010d\u0161ina portov nemala ani \u017eiadny v\u00fdpadok a zostala st\u00e1le v stave\u00a0<\/span>forwarding<\/span><\/strong><\/em>\u00a0.\u00a0<\/span>Edge porty<\/span><\/strong><\/em>\u00a0boli nakonfigurovan\u00e9, v\u00e4\u010d\u0161ina ostatn\u00fdch (tam, kde s\u00fa \u010fal\u0161ie Cisco switche) sa automaticky nastavila do\u00a0<\/span>P2P<\/span><\/strong><\/em>\u00a0.\u00a0Ak som sa pozrel pomocou\u00a0<\/span>show spanning-tree<\/code>, tak boli ozna\u010den\u00e9\u00a0<\/span>P2P Peer (STP)<\/span><\/strong>\u00a0, to znamen\u00e1, \u017ee susedn\u00e9 switch je v\u00a0\u00a0<\/span>STP m\u00f3de<\/span><\/strong><\/em>\u00a0.\u00a0Iba p\u00e1r portov pre\u0161lo stavy od\u00a0<\/span>blocking<\/span><\/strong><\/em>\u00a0, ale ve\u013emi r\u00fdchlo.\u00a0Na t\u00fdchto portoch bol v\u00e4\u010d\u0161inou nejak\u00fd mal\u00fd switch (a ob\u010das sa port nastavil do Shared).<\/span><\/p>\n
        Po tom, \u010do som nakonfiguroval v\u0161etky\u00a0<\/span>access switche<\/span><\/em>\u00a0, som pre\u0161iel na\u00a0<\/span>core switch<\/span><\/strong><\/em>\u00a0.\u00a0Prepnutie prebehlo obdobne ako ostatn\u00e9 switche.\u00a0Ale n\u00e1sledne u\u017e v\u0161etky\u00a0<\/span>P2P porty<\/span><\/strong><\/em>\u00a0boli ozna\u010den\u00e9 len ako\u00a0<\/span>P2P<\/span><\/strong>\u00a0, tak\u017ee by mali pracova\u0165 v\u00a0\u00a0<\/span>RSTP<\/span><\/strong>\u00a0m\u00f3de.\u00a0E\u0161te som sk\u00fasil sledova\u0165 nejak\u00fa komunik\u00e1ciu pomocou\u00a0<\/span>debug spanning-tree bpdu<\/code>a\u00a0<\/span>show logging<\/code>a tu som videl, \u017ee sa posielaj\u00fa\u00a0<\/span>RSTP BPDU<\/span><\/strong><\/em>\u00a0, tak\u017ee asi v\u0161etko automaticky pre\u0161lo do\u00a0<\/span>RSTP m\u00f3du<\/span><\/strong>\u00a0.<\/span><\/p>\n
        Ak niekto viete, ako sa pozn\u00e1, \u010di switch pracuje naozaj v RSTP (a nie v RSTP prepnut\u00e9 do STP), \u010di in\u00e9 podrobnosti, tak uv\u00edtam info.<\/span><\/p>\n
        Multiple Spanning Tree Protocol (MSTP)<\/span><\/h3>\n
        MSTP<\/span><\/em><\/strong>\u00a0vznikol ako roz\u0161\u00edrenie RSTP a bol definovan\u00fd v IEEE 802.1s, ale v roku 2003 spojilo do normy IEEE 802.1q, ktor\u00e1 popisuje VLANy (MSTP s VLANy priamo s\u00favis\u00ed).\u00a0Ako z\u00e1klad pou\u017e\u00edva<\/span>\u00a0RSTP<\/span><\/em><\/strong>\u00a0, ale navy\u0161e dovo\u013euje zoskupova\u0165 VLANy do<\/span>\u00a0spanning-tree in\u0161tanci\u00ed<\/span><\/em><\/strong>\u00a0(tak\u017ee pre ka\u017ed\u00fa skupinu be\u017e\u00ed samostatn\u00e1 in\u0161tancia STP).\u00a0V\u010faka tomu dovo\u013euje vyu\u017ei\u0165 viac ciest a vykon\u00e1va\u0165 jednoduch\u00fd<\/span>\u00a0load balancing<\/span><\/em>\u00a0(rozde\u013eovanie z\u00e1\u0165a\u017ee, ale statick\u00e9).\u00a0\u0160tandardne dovo\u013euje MSTP vytvori\u0165 a\u017e 65 r\u00f4znych rozdielnych logick\u00fdch topol\u00f3giou (in\u0161tanci\u00ed).<\/span><\/p>\n
        Cisco PVSTP<\/span><\/em><\/strong>\u00a0m\u00e1 v\u017edy jednu STP in\u0161tanciu pre jednu VLAN, teda \u010d\u00edm viac VLAN, t\u00fdm viac STP in\u0161tanci\u00ed a t\u00fdm v\u00e4\u010d\u0161ie za\u0165a\u017eenie switche.\u00a0Klasick\u00e9 STP (\u010di RSTP) m\u00e1 oproti tomu len jednu STP in\u0161tanciu pre v\u0161etky VLANy, \u010do znamen\u00e1 men\u0161iu HW n\u00e1ro\u010dnos\u0165, ale existuje len jedna virtu\u00e1lnej topol\u00f3gie a nem\u00f4\u017eeme teda rozdeli\u0165 z\u00e1\u0165a\u017e pre r\u00f4zne VLANy r\u00f4znu cestou.<\/span><\/p>\n
        D\u00f4le\u017eit\u00fdm term\u00ednom u MSTP je\u00a0<\/span>MST regi\u00f3n<\/span><\/em><\/strong>\u00a0.\u00a0Ten je tvoren\u00fd skupinou switchov, ktor\u00e9 maj\u00fa rovnak\u00fa konfigur\u00e1ciu (rovnako mapovan\u00e9 in\u0161tancie na VLANy).\u00a0Jednotliv\u00e9 regi\u00f3ny alebo switche bez MSTP s\u00fa dohromady prepojen\u00e9 klasick\u00fdm STP.\u00a0Tak\u017ee, aby sa switch stal s\u00fa\u010das\u0165ou regi\u00f3nu (a teda sa z\u00fa\u010dastnil MSTP), tak mus\u00ed ma\u0165 rovnak\u00fa konfigur\u00e1ciu ako ostatn\u00e9 (to znamen\u00e1 rovnak\u00e9 meno regi\u00f3nu, \u010d\u00edslo rev\u00edzie a mapovanie VLAN na in\u0161tancie).<\/span><\/p>\n
        MST in\u0161tancie<\/span><\/strong><\/em>\u00a0predstavuje mapovanie VLAN do skup\u00edn (ako bolo spomenut\u00e9 sk\u00f4r).\u00a0V jednom regi\u00f3ne m\u00f4\u017eeme vytvori\u0165 rad in\u0161tanci\u00ed (\u010d\u00edsla 0 a\u017e 4094, ale maxim\u00e1lne 65 in\u0161tanci\u00ed) so skupinami VLAN.\u00a0Defaultne s\u00fa v\u0161etky VLANy zaraden\u00e9 do in\u0161tancie 0 (MST00).<\/span><\/p>\n
        Pri prechode na MSTP alebo zmene zaradenie VLAN do MST in\u0161tancie d\u00f4jde k reinicializ\u00e1ciu a teda kr\u00e1tkemu v\u00fdpadku spojenia.\u00a0Prevod z Pin na MST by sa mal vykon\u00e1va\u0165 od jadra (centr\u00e1lneho prvku) a postupova\u0165 nadol.<\/span><\/p>\n
        Konfigur\u00e1cia MSTP na Cisco IOSu<\/span><\/h3>\n
        Pre prepnutie MST sta\u010d\u00ed jeden pr\u00edkaz.\u00a0Defaultne s\u00fa v\u0161etky VLANy v jednej in\u0161tancii (\u010d\u00edslo 0).\u00a0Lep\u0161ie je najprv vykona\u0165 konfigur\u00e1ciu in\u0161tanci\u00ed a a\u017e potom prepn\u00fa switch.<\/span><\/p>\n
        SWITCH (config) # spanning-tree mode mst<\/strong><\/span><\/pre>\n
        Konfigur\u00e1cia regi\u00f3nu a in\u0161tanci\u00ed sa vykon\u00e1va v MST konfigura\u010dnom m\u00f3de.<\/span><\/p>\n
        SWITCH (config) # spanning-tree mst configuration <\/strong>    \/\/ prepnutie do m\u00f3du \r\nSWITCH (config-mst) # show                             <\/strong>\/\/ inform\u00e1cie o regi\u00f3noch \r\nSWITCH (config-mst) # name region1                     <\/strong>\/\/ pomenovanie konfigur\u00e1cie \/ regi\u00f3nu \r\nSWITCH (config-mst) # revision 10                  <\/strong>    \/\/ rev\u00edzne \u010d\u00edslo konfigur\u00e1cia \r\nSWITCH (config-mst) # in\u0161tancia 1 vlan 100, 150     <\/strong>    \/\/ vytvorenie in\u0161tancie a zaradenie VLAN, vyu\u017eijeme poml\u010dku a \u010diarku<\/span><\/pre>\n
        \u010eal\u0161\u00ed rad (ladiacich) parametrov sa nastavuje pre cel\u00fd switch alebo port.<\/span><\/p>\n
        SWITCH (config) # spanning-tree mst 0 root primary           <\/strong>\/\/ nastav\u00ed switch ako root pre dan\u00fa in\u0161tanciu \r\nSWITCH (config) # spanning-tree mst 0 priority 32768         <\/strong>\/\/ nastav\u00ed prioritu switche pre dan\u00fa in\u0161tanciu \r\nSWITCH (config) # spanning-tree mst hello-time 1        <\/strong>     \/\/ nastav\u00ed hello time \r\nSWITCH (config-if) # spanning-tree mst 0 port-priority 64    <\/strong>\/\/ nastav\u00ed prioritu portu<\/span><\/pre>\n
        Zobrazenie inform\u00e1ci\u00ed o MST.<\/span><\/p>\n
        SWITCH # show spanning-tree mst<\/strong><\/span><\/pre>\n
        Flex Link<\/span><\/h3>\n
        Len stru\u010dne sa zmienim o zauj\u00edmav\u00e9 funkciu\u00a0<\/span>Flex Link<\/span><\/em><\/strong>\u00a0, ktor\u00e1 nes\u00favis\u00ed s STP.\u00a0Jedn\u00e1 sa len o jednoduch\u00fa funkciu, kedy m\u00e1m dve linky a jedna je definovan\u00e1 ako z\u00e1lo\u017en\u00fd.\u00a0Komunik\u00e1cia ide norm\u00e1lne iba po prim\u00e1rnej linke, ale vo chv\u00edli, ke\u010f t\u00e1to vypadne, sa prepne na z\u00e1lo\u017en\u00fd linku.\u00a0V\u00fdhodou je, \u017ee \u010das prepnutia je do 50ms.<\/span><\/p>\n
        Konfiguruje sa na prim\u00e1rnom interfacu (m\u00f4\u017ee to by\u0165 port alebo EtherChannel) a ur\u010dujeme jeho z\u00e1lo\u017en\u00fd.<\/span><\/p>\n
        SWITCH (config-if) # switchport backup interface f0 \/ 2<\/strong><\/span><\/pre>\n
        Pre zobrazenie inform\u00e1ci\u00ed o Flex Linku m\u00f4\u017eeme pou\u017ei\u0165.<\/span><\/p>\n
        SWITCH # show interface switchport backup<\/strong><\/span><\/pre>\n","protected":false},"excerpt":{"rendered":"
        Rapid Spanning Tree Protocol (RSTP) Maxim\u00e1lny \u010das, kedy konverguje STP je 50s (v praxi m\u00f4\u017eeme dosiahnu\u0165 ni\u017e\u0161ie hodnoty, ale tak okolo 30s), \u010do je pre…<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":431,"menu_order":2,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"_links":{"self":[{"href":"http:\/\/tech.sosthe.sk\/index.php\/wp-json\/wp\/v2\/pages\/494"}],"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=494"}],"version-history":[{"count":1,"href":"http:\/\/tech.sosthe.sk\/index.php\/wp-json\/wp\/v2\/pages\/494\/revisions"}],"predecessor-version":[{"id":495,"href":"http:\/\/tech.sosthe.sk\/index.php\/wp-json\/wp\/v2\/pages\/494\/revisions\/495"}],"up":[{"embeddable":true,"href":"http:\/\/tech.sosthe.sk\/index.php\/wp-json\/wp\/v2\/pages\/431"}],"wp:attachment":[{"href":"http:\/\/tech.sosthe.sk\/index.php\/wp-json\/wp\/v2\/media?parent=494"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}