Hot Backup Redundancy technology HSRP
1 , what is hot backup redundancy technology?
Hot Standby redundancy (HSRP) is the process of composing multiple routers into a "hot backup group", forming a virtual router, and
Select an active router in the group ( Active ), a backup router. Only the active router forwards the data when the active router
Down After the backup router, the backup router will select itself as the active router to forward the data and realize the redundancy of the gateway.
2 , active router and backup router elections
The election of the active router and the backup router is selected by priority, and the default priority of the router is - , the highest-priority selection
as the active router, the second option is the backup router. All routers in the hot-standby router group listen to each other through Hello packets
status when the active router has not been sent for a long time Hello packet, the active router is considered Down , the backup router will select itself as the active
The router forwards the data.
3 , HSRR Router Multicast message type
Hello : Every 3 seconds to advertise their priority and status information
coup : When the backup router has selected itself as the active router, send a coup message
resign : When the active router wants to Down or a higher priority router is sent Hello message when the active router sends a resign message
4 , HSRP six states of the router
Init : The state of the router when it was just started
Learn : Gets the virtual router's IP Address
Listen : All routers Listen Hello Package
speak : The router periodically sends Hello packet, and participate in the election of the active router and the backup router
Standby : The active router fails when backup router forwarding takes over data forwarding
Active : Backup router forwards data
5 , configuration instance
650) this.width=650; "title=" 1.jpg "src=" Http://s1.51cto.com/wyfs02/M01/78/D8/wKioL1aD8LyBrClZAAAjHOhdETA036.jpg " alt= "Wkiol1ad8lybrclzaaajhohdeta036.jpg"/>
HostPC1through the GatewayR1and theR2Access HostPC2and WillR1and theR2set toHSRP,R1for the active router,R2for backup
R1#config T
R1 (config) #interface gigabitethernet 0/0
R1 (config-if) #ip address 10.1.1.1 255.255.255.0
R1 (config-if) #no shutdown
R1 (config-if) #exit
R1 (config) #interface G0/1
R1 (config-if) #ip address 20.1.1.1 255.255.255.0
R1 (config-if) #no shutdown
R1 (config-if) #exit
R1 (config) #R1 rip
R1 (CONFIG-R1) #no auto-summary
R1 (CONFIG-R1) #version 2
R1 (CONFIG-R1) #network 10.1.1.0
R1 (CONFIG-R1) #network 20.1.1.0
R1 (CONFIG-R1) #passive-interface gigabitethernet 0/0//// set this interface as a passive interface
R1 (CONFIG-R1) #exit
R1 (config) #interface g0/0
R1 (config-if) #standby IP 10.1.1.254//// Define group name, virtual address
R1 (CONFIG-IF) #standby ten priority//// define the active router Priority
R2#config T
R2 (config) #interface g0/0
R2 (config-if) #ip address 10.1.1.2 255.255.255.0
R2 (config-if) #no shutdown
R2 (config-if) #exit
R2 (config) #interface G0/1
R2 (config-if) #ip address 20.1.1.2 255.255.255.0
R2 (config-if) #no shutdown
R2 (config-if) #exit
R2 (CONFIG-R2) #no auto-summary
R2 (CONFIG-R2) #version 2
R2 (CONFIG-R2) #network 10.1.1.0
R2 (CONFIG-R2) #network 20.1.1.0
R2 (CONFIG-R2) #passive-interface g0/0
R2 (CONFIG-R2) #exit
R2 (config) #interface g0/0
R2 (config-if) #standby IP 10.1.1.254
R2 (config-if) #standby preempt
650) this.width=650; "title=" 2.jpg "src=" Http://s2.51cto.com/wyfs02/M02/78/DA/wKiom1aD8LDi4_scAAB-OfMeP8E927.jpg " alt= "Wkiom1ad8ldi4_scaab-ofmep8e927.jpg"/>
650) this.width=650; "title=" 3.jpg "src=" http://s2.51cto.com/wyfs02/M00/78/DA/ Wkiom1ad8mlwbbsfaacvvgxjj-w197.jpg "alt=" Wkiom1ad8mlwbbsfaacvvgxjj-w197.jpg "/>
with PC1PINGPC2 , view packet delivery information, and then disconnect R1 of the g0/0 Interface View Status
650) this.width=650; "title=" 4.jpg "src=" Http://s2.51cto.com/wyfs02/M00/78/D8/wKioL1aD8PzBfupOAAC1ARtpKJc856.jpg " alt= "Wkiol1ad8pzbfupoaac1artpkjc856.jpg"/>
can see when R1 after the failure, a very short time to route or pass the
Experimental Success !
in this experiment, we can also configure a hot backup redundancy group to R2 set as the active router for load balancing.
Hot Backup Redundancy Technology HSRP