Methods for rapidly testing node reachability on multiple virtual private networks and evaluation

Reachability checks with pings are provided as supplementary VPN services of telecom carriers. With the expansion of cloud services, VPN monitoring services are also expanding. However, current routers do not have the short-interval reachability checks necessary for large-scale VPNs. Conventional ping tools can only check the reachability of one VPN (IP-network) at a time. In this paper, we devise ways to improve these ping tools. In order to test the reachability of a number of VPNs simultaneously, it is necessary to devise a routing table with a service ID and an interface mapping table. To ensure performance, it is necessary to invent new methods to send many packets while controlling the number of ping sending units and methods to order reachability checks of the VPNs. The improved ping tools can test the reachability of many VPNs simultaneously within several minutes.