Patent ID: 9544217
Date: 2017-01-10
CPC Classifications: H04L

Claim:
1. A computer implemented method of identifying a next hop from a focus device in a path of interconnected devices including switching devices and routing devices, configured in multiple virtual local area networks (VLANs) wherein the switching devices operate according to a switching address protocol and the routing devices operate according to a routing address protocol, the method implemented at a management computer having a query path to the interconnected devices and comprising: for the focus device which is one of the routing devices and which is configured to receive traffic addressed to a terminal destination, the traffic comprising packets which each carry a VLAN identifier which identifies which VLAN is used to route the packet, the step of dispatching a query message containing a query key based on a destination identifier for the terminal destination from the management computer to the focus device, the query message causing the focus device to identify and supply a next routing address for a hypothetical packet addressed to the terminal destination; receiving, from the focus device, a result message containing a new routing address which is the next routing address; ascertaining from the new routing address a corresponding switching address which is a switching address for switching traffic at one of the switching devices in a direction to the terminal destination; and using the switching address in a subsequent query key of a subsequent query message directed to said one of the switching devices, wherein the subsequent query message is directed to a forwarding database at said one of the switching devices, wherein the subsequent query message includes a VLAN identifier for the hypothetical packet, the VLAN identifier identifying the forwarding database to which the subsequent query message is directed and receiving a subsequent result message identifying an egress port of said one of the switching devices from the forwarding database of said one of the switching devices.