Automatic network topology detection for merging two isolated networks

A system, in a first network of two isolated networks, for detecting network topology to merge the two isolated networks, the system comprising:

• one or more computer readable storage media;
• a processing system operatively coupled with the one or more computer readable storage media;
• and
• program instructions stored on the one or more computer readable storage media that, when read and executed by the processing system, direct the processing system to:
• send probe messages to a second network of the two isolated networks, wherein the probe messages formatted for one or more passive protocols in the second network;
• receive replies to at least a portion of the probe messages from the second network indicating configuration parameters of the passive protocols;
• receive neighbor messages from the second network indicating configuration parameters of active protocols in the second network;
• and
• determine a network topology of the second network using the configuration parameters of the passive protocols and the configuration parameters of the active protocols, wherein to determine the network topology, the program instructions direct the processing system to determine a number of switches in the second network with uplinks to one or more gateways between the first network and the second network by determining a number of uplinks to the second network that are enabled on the one or more gateways.