H3C Technologies H3C S3600 Series Switches - Manual (Page 580)

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z If an IP address owner exists in a VRRP group, you can configure a priority for the IP address
owner. However your configuration will not take effect and the IP address owner will still be the
master of the VRRP group because the system considers the priority of the IP address owner to be
255 always.
z If an IP address owner exists in a VRRP group, the interface/port tracking function configured on
the IP address owner cannot take effect.
Interface tracking function of the VRRP group
When the VLAN interface of the master goes down, if you want the specified backup to become the
master, you can use the interface tracking function. With this function enabled for the VRRP group:
z If the tracked VLAN interface of the master goes down, the priority of the switch decreases
automatically by a specified value.
z The decrease of the master priority makes the priority of the backup tracking the interface become
higher, and thus the backup becomes the new master.
Port tracking function of the VRRP group
When a physical port of the master goes down, if you want the specified backup to become the master,
you can use the port tracking function. With this function enabled for the VRRP group:
z If the tracked physical port of the master goes down, the priority of the master decreases
automatically by a set value.
z The decrease of the master priority makes the priority of the backup tracking the port become
higher, and thus the backup becomes the new master.
You can enable Auto Detect on the master switch in a VRRP group, use the Auto Detect function to
detect the routes from the master switch to other networks, and use the detection results
(reachable/unreachable) to control the priority of the master switch, so as to realize the automatic
master-backup switchover. For details, please refer to Auto Detect Operation in this manual.
Operation Procedure of VRRP
z With VRRP enabled, the switches determine their respective roles in a VRRP group by priority. The
switch with the highest priority acts as the master, which will forward packets to outside networks,
and the switches with lower priorities act as backups. The master sends VRRP advertisements
periodically to notify that it is operating normally.
z When a backup receives a VRRP advertisement, it compares its own priority with that in the
advertisement. If its priority is lower, it remains as a backup. Otherwise, it becomes the master.
z A backup starts the advertisement interval timer after it receives the advertisement to wait for the
next one from the master. If the backup does not receive VRRP advertisements from the master