why we are use multicast address on routing like eigrp 22.214.171.124
EIGRP uses multicast address 126.96.36.199 for Neighbor Discovery, As you know Router does not Broadcast anything, but when EIGRP or any other protocol is configured it uses Multicast address for neighbor discovery, any router which is using this multicast address when passes to another router will get to know that there is a router who is EIGRP configured and they will become Neighbors.
188.8.131.52 to 184.108.40.206
fiirst thing we use multicast address to make neighborship.
the reason behind using multicast is each devices in the need not to listen that particular packet so it will create congestion in network. so in order to reduce or eliminate congestion we use multicast instead of broadcast.
that all i know, if i am wrong please let me know with better answer.