Interior Path Vector Routing Protocol (IPVP)

Interior Path Vector Routing Protocol (IPVP)

The Interior Path Vector Routing Protocol was designed by Conor Creagh as part of his MSc by Research in the Mobile & Internet Systems Laboratory, supervised by Prof. Cormac J. Sreenan, and published as:

C. Creagh and C. Sreenan, "An Interior Path Vector Routing Protocol," Proceedings. 2006 31st IEEE Conference on Local Computer Networks, Tampa, FL, USA, 2006, pp. 169-176, doi: 10.1109/LCN.2006.322096.

Available from


Current IGPs, such as IS-IS, OSPF and EIGRP, perform well in networks whose size would have been considered large when the protocols were being developed. Nowadays, however, it is not uncommon for large network service providers or global corporations to have networks that consist of tens of thousands of routers. We have seen that the link state protocols have built-in hierarchy that allows them to be scaled to a certain extent, but the most common resolution of the scalability problem today is to create a backbone of BGP within the enterprise that allows separate instances of IGPs to run within their measure. In this work, we have presented an interior gateway protocol that combines the path vector paradigm for route dissemination and loop avoidance with the ability to choose paths that are optimal according to the usual IGP standards of maximising bandwidth or minimising latency. We have seen that its footprint on a router is small in terms of memory requirements and that it presents no load that does not scale linearly with the size of the network in which it is running. Although IS-IS and OSPF will be faster to converge in smaller networks, it is expected that IPVP will be scalable to several thousand nodes without suffering from the computational overheads and limitations of link state protocols. Such scalability offers network operations the possibility of running a single protocol across large networks, thereby avoiding the problems associated with hierarchies, route re- distribution and managing metrics from different protocols.


Since June 2023, IPVP is available as part of the open-source freerouter platform:

Thanks to "mc36" from the rare/freertr team for implementing the protocol.

If you use the protocol in your research, please cite the paper above and acknowledge the use of freerouter.

Mobile and Internet Systems Laboratory

Department of Computer Science, Western Gateway Building, University College Cork, Western Road, Cork, Ireland.