Hello Bhawandeep
@davidilles is correct. Here is a quote from the CCIE Routing and Switching v5.0 Official Cert Guide. It’s an older cert guide, but the comments it states are valid:
Originally, the primary use of the EIGRP RID has been to prevent routing loops in EIGRP environments using redistribution. The RID identifies the originating router for external routes injected into the EIGRP domain. Each external route was attached the RID of the router that redistributed it into EIGRP. If an external route is received with the same RID as the local router, the route is discarded. This feature is designed to reduce the possibility of routing loops in networks where route redistribution is being performed on more than one router. EIGRP RID was not originally advertised with internal routes.
With recent IOS releases, however, the EIGRP RID is also advertised with internal routes. As a result, each route advertised in EIGRP, internal or external, carries the RID of the router that injected it into EIGRP. The logic of using the RID remains the same—a router will discard every received route carrying the router’s own RID.
I will suggest to Rene that he update the lesson accordingly.
I hope this has been helpful!
Laz