What effect does a small interval for sending VRRP packets have on the backup device?

A small interval for sending VRRP (Virtual Router Redundancy Protocol) packets can indeed have the effect of causing status flapping of the backup device. VRRP is designed to facilitate automatic routing failover, allowing one device to take over as the active router when the primary device fails.

When the interval for sending VRRP packets is small, the frequency of status checks increases. This can lead to the backup device receiving rapid updates about the state of the primary device. If the primary device experiences temporary issues or network instability, the backup may prematurely assume the role of the active device due to frequent packet transmission suggesting that the primary is down. This results in frequent changes between active and backup states, which is referred to as status flapping.

Such flapping can lead to instability in the network, resulting in momentary periods where the active router changes back and forth, potentially disrupting traffic flow and causing confusion in the network routing. Therefore, a small interval can impair the intended reliability of VRRP, causing a flapping scenario rather than fostering a stable or more responsive backup device.