As i read that EIGRP supports Multiple ASes on a single router but i don't understand this sentence .. so can any one help me to understand it .
And i want to understand how EIGRP redistribute with IGRP the routes...
EIGRP multiple ASs are used in designs when it is required to partition your AS, into smaller parts for design consideration, a single EIGRP process is analogous to an area of a link-state protocol. Multiple routing processes can be configured to achieve a hierarchy.
You can configure more than one EIGRP autonomous system on the same router, but Cisco does not recommend it. Multiple EIGRP autonomous systems on the same router that use mutual redistribution can cause discrepancies in the EIGRP topology table. Cisco recommends you configure only one EIGRP autonomous system in any single autonomous system.
HTH, please do rate all helpful replies,