How Does the Adjustment to the VGMP Hello Interval Affect the Network?
VGMP Hello packets are known as heartbeat packets and are used to check the operating status of the active and standby firewalls. If the standby VGMP group does not receive any VGMP Hello packet from the peer within three consecutive Hello intervals, the standby VGMP group considers that the peer fails and switches to the active state. Therefore, a short VGMP Hello interval enhances the failure response speed of the firewall.
However, if the interval is too short, the hot standby status may become unstable. When the CPU is overloaded, the task of sending VGMP Hello packets cannot be scheduled, resulting in a false switchover. Therefore, the default value, 1 second, is recommended.