Data processing

A non-transitory computer-readable storage medium having computer readable instructions stored thereon, wherein, when executed by a processor, cause a computing device to perform a method for processing data in a packet-switched network, the method comprising, at a first device:

• configuring the first device to snoop control packets of a predetermined control plane protocol in the network, the predetermined control plane protocol being operated by a plurality of other devices in the network to obtain Layer 2 information on the basis of known Layer 3 information, wherein the first device does not operate the predetermined control plane protocol in the network;
• and
• in response to identifying that a given snooped packet was generated according to the predetermined control plane protocol, extracting, from the given snooped control plane protocol packet, Layer 3 information associated with a second device in the plurality on the basis of known Layer 2 information associated with the second device, wherein the second device is connected to the first device.