Vrrp Applications - D-Link xStack DGS-3610 Series Configuration Manual

Chapter 46 VRRP Configuration
than one device within the group becomes Master, repeat the preempt process in step 1.
In this process, the device with the maximum priority will be selected as the master
device to execute the VRRP backup function.
Figure 46-1 VRRP working principles
Once a master device is elected in a VRRP backup group, the hosts in the LAN will execute
route forwarding through that master device. The communication process is illustrated in
Figure 47-1. As shown in Figure 47-1, devices R1 and R2 are connected with LAN
192.168.12.0/24 through Ethernet interface Fa0/0, on which the VRRP is configured. All
hosts in the LAN use the IP of the virtual device of the VRRP group as the default gateway.
The hosts in the LAN only know the virtual router of the VRRP group, while the master router
in the VRRP which is implementing the forwarding function is transparent to them. For
example, if host PC 1 in the LAN is communicating with host PC 2 in another network, PC 1
will use the virtual router as the default gateway to send packets to the network of PC 2.
When receiving the packets, the master router in the VRRP group forwards them to PC 2.In
this communication process, PC 1 only feels the virtual device but does not know whether
device R1 or R2 is playing the role. The master device is elected between devices R1 and
R2 in the VRRP group. Once the master device fails, the other device automatically
becomes the master.

46.2 VRRP Applications

There are two VRRP application modes: basic and advanced. In basic applications, simple
redundancy is implemented with a single backup, while in advanced applications multiple
backup groups are used to implement both route redundancy and load balancing.
46-2
DGS-3610 Series Configuration Guide