10.CCNA, CCNP configuration OSPF study notes summary
Lesson 9 HSRP
First, the basic concept of HSRP
A proprietary hot standby router redundancyprotocol from Cisco; a protocol that addresses backup redundancy for active andstandby gateways.
HSRP election: select the main gateway,backup gateway
Virtual IP: It is on the same networksegment as the real gateway but cannot be the same IP address; it only forms amapping relationship with the primary gateway.
Target IP: 126.96.36.199; encapsulated by UDP,port number 1985
Source IP: own interface IP
Target Mac: 00‐00‐0c‐07‐ac‐x generationx table //xx group number source Mac: own interface Mac address
Reference RFC: rfc2281
Second, the components of HSRP, the maingateway (active router): HSRP elects the router with the highest priority,mainly used to receive the data of the sending terminal PC to the externalnetwork, the backup gateway: HSRP elects the router with the second highestpriority Mainly used