Customer would have the requirement to monitor the IPsec tunnel (NSD via edge / NSD via gateway) and would like to receive the notification mail incase IPsec tunnel went down and came up.
VMware Velocloud SD-WAN
Incase customer didn't enable the vpn tunnel down events on alerts configuration, customer wouldn't receive the VPN_Tunnel_DOWN alert.
VPN_Tunnel_DOWN alert behaviour:
i) NSD via Edge tunnel - Alert will be generated in case the tunnel went down.
ii) NSD via Gateway tunnel - Alert will be generated in case both primary and redundant tunnel went down from gateway to the destination.
VPN_Tunnel_State_Change event:
This event will be generated if there's any change of state happened for the IPsec tunnel
Customer shall use both VPN_Tunnel_DOWN alert and VPN_Tunnel_State_Change event to track the ipsec tunnel on their monitoring tool.