The basic concept of a .VRRP

     VRRP (Virtual Router Redundancy Protoco1, referred to as VRRP) can be good to avoid static defects specified gateway.

     1. Overview agreement. In VRRP agreement, there are two important concepts: VRRP virtual router and router, the master router and the backup router.

VRRP routers are running VRRP router is a physical entity, means the VRRP virtual router protocol created is a logical concept.

A group of VRRP router to work together to form a virtual router. The external performance virtual router has a unique fixed

Logical router IP address and MAC address. The role of the router in a VRRP group has two mutually exclusive: the master router

And backup router, a VRRP group and only one in the master role of the router, there may be one or more backup in

Router role. VRRP protocol using a selection policy selected as the master router from the group, responsible for the corresponding ARP and IP forwarding number

According to the package, the other group as a standby routers in a standby state. When for some reason the master router fails,

Backup router can postpone a new master router when a few seconds. Because of this very rapid switching and do not change the IP address and MAC

Address, so the system is transparent to the end user.

     2. works. VRRP router has a unique identifier: VRID, the range of 0-255. The router is the only external performance

Virtual MAC address format, the address is 00-00-5E-00-01- [VRID].
Master router is responsible for answering ARP requests to do with the MAC address. Thus, switch anyway, to ensure that the terminal device is unique

The same IP and MAC addresses, reducing the impact of the handover of the terminal device.


Two .BGP agreement

  1. BGP is an external routing protocol for passing routing information between AS

  2. It is a distance vector routing protocol, to avoid the generation of a loop from the design

  3. Routing incidental attribute information

  4. Transport protocols: TCP, port 179 supports CIDR (Classless Inter-Domain Routing)

  5. Routing updates: send only incremental routes

  6. Rich routing and route filtering policy