CCNA 2 - Capitulo 9.1

CCNA 2 - Capitulo 9.1

1. HSRP STATES AND TIMERS

   • 2.LEARN
     • THE ROUTER HAS NOT DETERMINED THE VIRTUAL IP
       • AND HAS NOT YET SEEN A HELLO MESSAGE FROM THE ACTIVE ROUTER
     • THE ROUTER WAITS TO HEAR FROM THE ACTIVE ROUTER
   • 3.LISTEN
     • ROUTER KNOW VIRTUAL IP ADDRESS
       • BUT THE ROUTER IS NEITHER THE ACTIVE ROUTER NOR THE STANDBY
   • 4.SPEAK
     • THE ROUTER SENDS PERIODIC HELLO MESSAGES
   • 5.STANDBY
     • THE ROUTER IS A CANDIDATE TO BECOME THE NEXT ACTIVE ROUTER
     • WILL BECOME ACTIVE IF IT DOES NOT RECEIVE A HELLO MESSAGE
       • FROM THE ACTIVE ROUTER AFTER 10 SECONDS (HOLDTIME)
   • 1.INITIAL
     • CONFIGURATION CHANGE
     • INTERFACE FIRST BECOMES AVAILABLE
   • 6.ACTIVE
     • THE ROUTER WON THE ELECTION
   • ACTIVE AND STANDBY HSRP ROUTERS SEND HELLO PACKETS HSRP GROUP MULTICAST
     • EVERY 3 SECONDS BY DEFAULT

2. HOT STANDBY ROUTER PROTOCOL (HSRP) - IPV4

   • ELECTION PROCESS - HSRP PRIORITY AND PREEMPTION
     • 1 ) HSRP PRIORITY
       • CAN BE USED TO DETERMINE THE ACTIVE ROUTER
       • THE RANGE OF HSRP PRIORITY 0 A 255
       • HIGHEST HSRP PRIORITY WILL BECOME ACTIVE ROUTER
         • BY DEFAULT IS 100
           • IF THE PRIORITIES ARE EQUAL
             • NUMERICALLY HIGHEST IPV4 ADDRESS IS ELECTED AS THE ACTIVE ROUTER.
       • CONFIGURE A ROUTER TO BE ACTIVE USE
         • R1(CONFIG-IF)#STANBDY PRIORITY
     • 2) HSRP PREMPTION (APROPRIAÇÃO)
       • WHATS IS PREMPTON ?
         • IS THE ABILITY OF AN HSRP ROUTER TO TRIGGER THE RE-ELECTION PROCESS.
       • BY DEFAULT AFTER ROUTER BECOMES THE ACTIVE ROUTER
         • IT WILL REMAIN THE ACTIVE ROUTER EVEN IF ANOTHER ROUTER COMES ONLINE WITH A HIGHER HSRP PRIORITY.
       • WHATS IS PURPOSE?
         • TO FORCE A NEW HSRP ELECTION PROCESS
           • WHEN PRIORITY ROUTER COMES ONLINE
             • R1(CONFIG-IF)# STANDBY PREMPT
       • WITH PREMPTION ENABLED , A ROUTER THAT COMES ONLINE WITH A
         • HIGHER HSRP PRIORITY WILL ASSUME THE ROLE OF THE ACTIVE ROUTER
   • HSRP OVERVIEW
     • CISCO PROVIDES HSRP AND HSRP FOR IPV6
       • AVOID LOSING OUTSIDE NETWORK ACCESS IF YOUR DEFAULT GATEWAY FAILS
     • HIGH NETWORK AVAILABILITY BY
       • FIRST HOP ROUTING REDUNDANCY IPV4 GATEWAY
     • HSRP IS USED IN A GROUP OF ROUTERS SELECTING
       • ACTIVE DEVICE
         • ROUTING PACKETS
         • FORWARDING
       • STADBY DEVICE
         • TAKES OVER WHEN THE ACTIVE DEVICE FAILS OR PRE SET CONDITIONS ARE MET
         • MONITOR THE OPERATIONAL STATUS OF THE HSRP GROUP
     • WHATS YOUR PURPOSE ?
       • ALLOW FOR TRANSPARENT FAILOVER OF FIRST HOP IP DEVICE