Routing protocols use different traffic types to control how routing information are exchanged.
Unicast: traffic is exchanged between one sender and one receiver, communication between two points.
Multicast: traffic is exchanged between one sender and group of receivers. IPv4 reserved address space is 184.108.40.206 – 220.127.116.11. IPv6 reserved multicast addresses have the prefix FF00:/8
Broadcast: one receiver send traffic to all devices in the subnet. Local subnet address is 255.255.255.255. IPv6 does not have broadcast traffic type.
Anycast: traffic is exchanged between one sender and nearest receiver from a group.
Early routing protocols used only broadcast traffic, but modern use multicast addresses.
- 18.104.22.168 – Used by OSPFv2: All OSPF routers
- 22.214.171.124 – Used by OSPFv2: All Designated routers
- 126.96.36.199 – Used by RIPv2
- 188.8.131.52 – Used by EIGRP
- FF02::5 – Used by OSPFv3: All OSPF Routers
- FF02::6 – Used by OSPFv3: All Designated Routers
- FF02::9 – Used by RIPng
- FF02::A – Used by EIGRP for IPv6