The number of EIGRP neighbors are not related to IOS versions. I guess, practically there shouldnt be a limitation on the number of neighbors for a router running EIGRP. EIGRP discovers neighbors using multicast hellos.
The only limitation on a router, would be the memory, required to store a volume of routes from each neighbor. Note that eigrp also maintains a topology table.
Sankar Nair
UC Solutions Architect
Pacific Northwest | CDW
CCIE Collaboration #17135 Emeritus
