IPv6 - IPv6

IPv4 addresses are 32 bits long and are represented in decimal format. IPv6 addresses are 128 bits long and represented in hexadecimal format.

The loopback address with IPv4 is 127.0.0.1. With IPv6, that address is ::1.

Anycast addresses identify multiple interfaces, which is the same as multicast; however, the big difference is that the anycast packet is only delivered to one address, the first one it finds defined in the terms of routing distance. This address can also be called one-to-one-of-many.

These addresses are meant for nonrouting purposes like link-local, but they are almost globally unique so it is unlikely they will have an address overlap. Unique local addresses were designed as a replacement for site-local addresses.

Link-local addresses are meant for throwing together a temporary LAN for meetings or a small LAN that is not going to be routed but needs to share and access files and services locally.

Unlike RIPng and OSPFv3, you need to configure EIGRP both from global configuration mode and from interface mode, and you have to enable the command with the no shutdown command.

EIGRPv6's multicast address stayed very near the same. In IPv4 it was 224.0.0.10; now it is FF02::A (A=10 in hexadecimal notation).

Adjacencies and next-hop attributes now use link-local addresses, and OSPFv3 still uses multicast traffic to send its updates and acknowledgments with the addresses FF02::5 for OSPF routers and FF02::6 for OSPF designated routers. These are the replacements for 224.0.0.5 and 224.0.0.6, respectively.