Transit prevention in hub-and-spoke topologies using link state protocols

An apparatus for controlling transmission of data packets in a communications network comprising hubs and spokes, said apparatus comprising:

• means for generating a link-state advertisement;
• means for computing a shortest path tree based on said link-state advertisement, wherein said shortest path tree comprises all data transmission routes in the tree except links leading from a spoke to a hub;
• means for creating a routing table based on the shortest path tree;
• and
• means for transmitting said data packets in said communications network based on said link-state advertisement, wherein the transmission of said data packets are controlled by instructions provided in said routing table.

An apparatus for controlling transmission of data packets in a communications network comprising hubs and spokes, said apparatus comprising:

• a computing module that computes a shortest path tree based on a link-state advertisement, wherein said shortest path tree comprises all data transmission routes in the tree except links leading from a spoke to a hub;
• a routing table comprising the shortest path tree;
• and
• a transmitting module that transmits said data packets in said communications network based on said link-state advertisement, wherein the transmission of said data packets are controlled by instructions provided in said routing table.

A method of controlling transmission of data packets in a communications network, said method comprising:

• designating all networking devices in a portion of said communications network as either hubs or spokes;
• communicating a link-state advertisement to each connected hub and spoke in said portion of said communications network;
• computing a shortest path tree at all said hubs and said spokes based on said link-state advertisement, wherein said shortest path tree comprises all data transmission routes in the tree except links leading from a spoke to a hub, and wherein said computing comprises truncating said shortest path tree at said hubs only for links leading from said spoke to said hub;
• creating a routing table at each said hub and said spoke based on the truncated shortest path tree;
• and
• transmitting said data packets in said communications network based on said link-state advertisement,
• wherein the transmission of said data packets are controlled by instructions provided in said routing table.