[RS] glbp

Glbp is a Cisco proprietary protocol that is generally supported by high-end devices. The objective of glbp is the same as that of HSRP and vrrp. Multiple routers are used to provide gateway load capabilities for the LAN. However, HSRP and vrrp are used to assign multiple routers to a group and Virtualize them into an IP address, the user sends the data to this IP address. There is only one primary router in the group, and the others are backup routers. Only the primary router can forward the user's data packets, the backup router has the opportunity to provide data forwarding only when the primary router is unavailable. It can be seen that the backup routers of HSRP and vrrp are not used at ordinary times. To make all routers used, only multiple groups are configured, in addition, all user hosts must be directed to the corresponding group IP addresses.

Considering the above problems, glbp also provides users with a single IP address When configuring multiple routers into one group, the additional function is to allow all members in the group to forward data to users without idle routers. The solution is to provide users with a single IP Address while each vro provides users with different MAC addresses. In this way, the packets sent to the Group IP address are successfully shared among the vrouters. Each member in the group also has a hello packet for communication. Send one packet in 3 seconds and use the multicast address 224.0.0.102. The UDP port number is 3222.

In the glbp group, select a vro as the active virtual gateway (avg) and another vro as the AVG backup (AVF active virtual forwarders) to replace the AVG role when the AVG is unavailable. In the group, the AVG task only assigns virtual MAC addresses to Members, because everyone is the same IP address. as long as their MAC addresses are different, they can provide data forwarding for users at the same time, if the target MAC address of a user's data packet is sent to the user, the user will forward the corresponding data packet.

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