Momwe VRRP protocol imagwirira ntchito

FHRP (First Hop Redundancy Protocol) - gulu la ma protocol opangidwa kuti apange kusakhazikika pachipata. Lingaliro lalikulu la ma protocol awa ndikuphatikiza ma router angapo kukhala rauta imodzi yokhala ndi adilesi wamba ya IP. Adilesi ya IP iyi idzaperekedwa kwa olandira ngati adilesi yolowera pachipata. Kukhazikitsa kwaulere kwa lingaliroli ndi protocol ya VRRP (Virtual Router Redundancy Protocol). M'nkhaniyi, tikambirana zoyambira za VRRP protocol.

Ma routers a VRRP amaphatikizidwa kukhala rauta imodzi. Ma router onse pagulu amagawana adilesi yofanana ya IP (VIP) ndi nambala yamagulu wamba, kapena VRID (Virtual Router Identifier). Rauta imodzi imatha kukhala m'magulu angapo, omwe aliyense ayenera kukhala ndi VIP/VRID yakeyake.

Pankhani ya Cisco, rauta yeniyeni imayikidwa pa mawonekedwe otisangalatsa ife ndi lamulo:

R1(config-if)# vrrp <group-number> ip <ip-address>

Ma routers onse amagawidwa m'mitundu iwiri: VRRP Master ndi VRRP Backup.

VRRP Master ndiye rauta yomwe imatumiza mapaketi agulu ili.

VRRP Backup ndi rauta yomwe ikuyembekezera paketi kuchokera kwa Master. Ngati mapaketi ochokera kwa Master asiya kubwera, Zosunga zobwezeretsera zimayesa kusinthira ku Master state.

Router imakhala Master ngati ili ndi zofunika kwambiri. Master nthawi zonse amaulutsa mauthenga ku adilesi yowulutsa ya 224.0.0.18 kuti auze ma Backup routers kuti ikuyenda. Master amatumiza mauthenga molingana ndi Adver Timer, yomwe ndi 1 sekondi mosakhazikika.

Apa, gulu adilesi 00:00:5E:00:01:xx amagwiritsidwa ntchito ngati adilesi ya MAC ya wotumiza, pomwe xx ndi VRID mumtundu wa hexadecimal. Mu chitsanzo ichi, gulu loyamba likugwiritsidwa ntchito.

Ngati ma Backup routers salandira mauthenga mkati mwa ma Adver Timers atatu (Master Down Timers), ndiye kuti Master watsopanoyo amakhala rauta yomwe ili patsogolo kwambiri, kapena rauta yokhala ndi IP yapamwamba kwambiri. Pankhaniyi, Backup rauta yokhala ndi chofunikira kwambiri imasokoneza gawo la Master ndikuyika patsogolo pang'ono. Komabe, zosunga zobwezeretsera zitayimitsidwa, Kusunga sikungatenge m'malo mwa Master.

R1(config-if)# no vrrp <group-number> preempt

Ngati rauta ya VRRP ndiye mwini wake wa adilesi ya VIP, ndiye kuti nthawi zonse imatenga udindo wa Master.

Kufunika kwa VRRP kumayikidwa pamtengo kuyambira 1 mpaka 254. Mtengo 0 umasungidwa pamilandu yomwe Mbuye akufuna. chotsani kutenga udindo panjira. Mtengo wa 255 umayikidwa ku router mwini wa VIP. Chofunikira choyambirira ndi 100, koma chitha kukhazikitsidwa pakuwongolera:

R1(config-if)#vrrp <group-number> priority <priority 1-254>

Apa titha kuwona kufunikira kwa rauta ikakhazikitsidwa pakuwongolera:

Ndipo nayi nkhani pamene rauta ndiye mwini wa VIP:

Router ya VRRP ikhoza kukhala ndi zigawo zitatu: Initialize, Backup, Master. Router imasintha motsatizana maiko awa.

Mu Initialize state, rauta ikuyembekezera kuyamba. Ngati rauta iyi ndi mwini wake wa adilesi ya VIP (choyambirira ndi 255), ndiye kuti rautayo imatumiza mauthenga kuti imakhala Master. Amatumizanso pempho laulere la ARP, kumene adilesi ya MAC yochokera ndi yofanana ndi adilesi ya rauta. Kenako imasinthidwa kupita ku Master state. Ngati rauta si mwini wa VIP, ndiye kuti imapita ku Backup state.

Mu State Backup, rauta imadikirira mapaketi kuchokera kwa Master. Router m'boma lino sayankha zopempha za ARP kuchokera ku adilesi ya VIP. Simavomerezanso mapaketi omwe ali ndi adilesi ya MAC ya rauta yeniyeni ngati adilesi yomwe akupita.

Ngati zosunga zobwezeretsera sizilandira mauthenga kuchokera kwa Master panthawi ya Master Down Timer, ndiye kuti zimatumiza uthenga ku VRRP kuti ikhala Master. Kenako imatumiza uthenga wowulutsa wa VRRP momwe magwero a MAC adilesi ali ofanana ndi adilesi ya rautayi. Mu uthenga uwu, rauta ikuwonetsa zofunikira zake.

Mu Master state, ma rauta amapangira mapaketi otumizidwa ku rauta yeniyeni. Imayankhanso zopempha za ARP ku VIP. Master amatumiza mauthenga a VRRP nthawi iliyonse ya Adver kuti atsimikizire kuti ikugwira ntchito.

*May 13 19:52:18.531: %VRRP-6-STATECHANGE: Et1/0 Grp 1 state Init -> Backup
*May 13 19:52:21.751: %VRRP-6-STATECHANGE: Et1/0 Grp 1 state Backup -> Master

VRRP imalolanso kusanja kwa katundu pama router angapo. Kuti muchite izi, magulu awiri a VRRP amapangidwa pa mawonekedwe amodzi. Gulu limodzi limapatsidwa udindo waukulu kuposa lina. Pankhaniyi, pa rauta yachiwiri, choyambirira chimayikidwa mosiyana. Iwo. ngati pa rauta imodzi gulu loyamba ndi 100, ndipo gulu lachiwiri ndi 200, ndiye pa rauta ina, gulu loyamba lidzakhala 200, ndipo lachiwiri 100.

Monga tanenera kale, gulu lirilonse liyenera kukhala ndi VIP yakeyake. Zotsatira zake, timapeza ma adilesi awiri a ip omwe amatumizidwa ndi ma routers awiri, omwe amatha kukhala ngati chipata chosasinthika.

Theka la makompyuta amapatsidwa adilesi imodzi yosasinthika, theka linalo. Chifukwa chake, theka la magalimoto lidzadutsa rauta imodzi, ndipo theka kudutsa lina. Ngati imodzi mwa ma routers ikulephera, yachiwiri imatenga ntchito ya ma VIP onse awiri.

Chifukwa chake, VRRP imakulolani kuti mukonzekere kulolerana kolakwika kwa chipata chosasinthika, ndikuwonjezera kudalirika kwa intaneti. Ndipo pankhani yogwiritsa ntchito ma router angapo, mutha kuwongoleranso katundu pakati pa ma routers enieni. Kulephera kuyankha nthawi kumatha kuchepetsedwa pochepetsa zowerengera.

Source: www.habr.com