Editing Enhanced Interior Gateway Routing Protocol (section)

=== Distance vector routing protocol ===
Cisco Systems now classifies EIGRP as a distance vector routing protocol, but it is normally said to be a hybrid routing protocol.<ref name=intro /><ref name=ccie>[http://www.informit.com/library/content.aspx?b=CCIE_Practical_Studies_I&seqNum=116 CCIE Practical Studies, Volume I | Chapter 11. Hybrid: Enhanced Interior Gateway Routing Protocol (EIGRP)] {{Webarchive|url=https://web.archive.org/web/20140426202321/http://www.informit.com/library/content.aspx?b=CCIE_Practical_Studies_I&seqNum=116 |date=2014-04-26 }}. InformIT (2008-06-13). Retrieved on 2014-05-30.</ref> While EIGRP is an advanced routing protocol that combines many of the features of both link-state and distance-vector routing protocols, EIGRP's [[#Technical details|DUAL algorithm]] contains many features which make it more of a distance vector routing protocol than a link-state routing protocol.<ref name=ccie /><ref>Ashraf, Muhammad Irfan, et al. "[http://www.ijcsmr.org/vol2issue4/paper346.pdf Comparative Analysis of Link State and Hybrid Routing Protocols] {{Webarchive|url=https://web.archive.org/web/20131109014953/http://www.ijcsmr.org/vol2issue4/paper346.pdf |date=2013-11-09 }}"</ref> Despite this, EIGRP contains many differences from most other distance-vector routing protocols, including:<ref name=Albrightson>Albrightson, R., Garcia-Luna-Aceves, J. J., & Boyle, J. (1994, May). EIGRP a fast routing protocol based on distance vectors. In Proc. Network ID/Interop (Vol. 94, pp. 136-147).</ref>

* the use of explicit hello packets to discover and maintain adjacencies between routers.
* the use of a reliable protocol to transport routing updates.
* the use of a feasibility condition to select a loop-free path.
* the use of diffusing computations to involve the affected part of the network into computing a new shortest path.