Reference Guide

CAUTION: Increasing the advertisement interval increases the VRRP Master dead interval, resulting in an
increased failover time for Master/Backup election. Take caution when increasing the advertisement interval, as
the increased dead interval may cause packets to be dropped during that switch-over time.
Table 76. Recommended VRRP Advertise Intervals on the S4820T
Recommended Advertise Interval Groups/Interface
Total VRRP Groups S4820T S4820T
Less than 250 1 second 12
Between 250 and 450 2–3 seconds 24
Between 450 and 600 3–4 seconds 36
Between 600 and 800 4 seconds 48
Between 800 and 1000 5 seconds 84
Between 1000 and 1200 7 seconds 100
Between 1200 and 1500 8 seconds 120
VRRP Configuration
By default, VRRP is not configured.
Configuration Task List
The following list specifies the configuration tasks for VRRP.
• Creating a Virtual Router (mandatory)
• Assign Virtual IP Addresses mandatory)
• Setting VRRP Group (Virtual Router) Priority (optional)
• Configuring VRRP Authentication (optional)
• Disabling Preempt (optional)
• Changing the Advertisement Interval (optional)
• Track an Interface or Object
• Setting VRRP Initialization Delay
For a complete listing of all commands related to VRRP, refer to FTOS Command Line Reference Guide .
Creating a Virtual Router
To enable VRRP, create a virtual router. In FTOS, the virtual router identifier (VRID) identifies a VRRP group.
To enable or delete a virtual router, use the following commands.
• Create a virtual router for that interface with a VRID.
INTERFACE mode
vrrp-group vrid
The VRID range is from 1 to 255.
NOTE: The interface must already have a primary IP address defined and be enabled, as shown in the second
example.
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