Cisco 500 series Administration Manual page 482

VRRP
Configuring VRRP
Configuring VRRP
STEP 1
STEP 2
Cisco 500 Series Stackable Managed Switch Administration Guide
In Figure , if Router A, the virtual router master, fails, a selection process takes
place to determine if virtual router backups B or C must take over. If Routers B and
C are configured with the priorities of 101 and 100, respectively, Router B is
elected to become virtual router master because it has the higher priority. If both
have the same priority, the one with the higher IP address value is selected to
become the virtual router master.
By default, a preemptive feature is enabled, which functions as follows:
• Enabled - When a VRRP router is configured with higher priority than the
current master is up, it replaces the current master.
• Disabled - Even if a VRRP router with a higher priority than the current
master is up, it does not replace the current master. Only the original master
(when it becomes available) replaces the backup.
VRRP Advertisements
The virtual router master sends VRRP advertisements to routers which are in the
same group (configured with the same virtual router identification).
The VRRP advertisements are encapsulated in IP packets and sent to the IP v4
Multicast address assigned to the VRRP group. The advertisements are sent every
second by default; the advertisement interval is configurable.
The advertisement Interval is in mS (Range: 50 - 40950, Default: 1000). A non-
value is invalid.
• In VRRP version 3, the operational advertise interval is rounded down the
nearest 10ms.
• In VRRP version 2, the operational advertise interval is rounded down to the
nearest second. The minimum operational value is 1 sec.
VRRP properties can be configured and customized in the IPv4 VRRP Virtual
Routers page.
Click IP Configuration > IPv4 VRRP Virtual Routers. The IPv4 VRRP Virtual
Routers page opens.
To add a virtual router, click ADD. The Add Virtual Router page opens.
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