Why Sequence Numbers in AODV
	n To avoid using old/broken routes – To determine which route is newer n To prevent formation of loops – Assume that A does not know about failure of link C-D because RERR sent by C is lost – Now C performs a route discovery for D. Node A receives the RREQ (say, via path C-E-A) – Node A will reply since A knows a route to D via node B – Results in a loop (for instance, C-E-A-B-C )