You can configure the advertisement time interval (in seconds) between sending advertisement messages. This interval permits fast network convergence with standardized VRRP failover. However, losing connections to servers for more than a second can result in missing critical failures. Customer network uptime in many cases requires faster network convergence, which means network problems must be detected within hundreds of milliseconds. Fast Advertisement Enable and Fast Advertisement Interval meet these requirements
Fast Advertisement Enable acts like a toggle device for the Advertisement Interval and the Fast Advertisement Interval. When Fast Advertisement Enable is enabled, the Fast Advertisement Interval is used instead of the Advertisement Interval.
The Fast Advertisement Interval is similar to the Advertisement Interval parameter except for the unit of measure and the range. The Fast Advertisement Interval is expressed in milliseconds and the range is from 200 to 1000 milliseconds. This unit of measure must be in multiples of 200 milliseconds, otherwise the system displays an error.
When you enable the fast advertisement interval, VRRP can communicate with other switch ports and networking products that have the same configuration.