- Have their high-level 3-bits set to 001 (2000::/3)
- Global routing prefix is 48 bits or less.
- Subnet ID is comprised of whatever bits are left over after global routing prefix.
- The primary address expected to comprise the IPv6 Internet are from the 2001://16 subnet.
EUI – Extended Unique Identifier – used in part of Auto-Configuration where a host receives a prefix from the default router and then auto-generates the host portion. For example:
ipv6 address 2001:1234:ABCD:5678::/64 eui-64
R4#show ipv6 int lo12
Loopback12 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::A8BB:CCFF:FE00:400
No Virtual link-local address(es):
Global unicast address(es):
2001:1234:ABCD:5678:A8BB:CCFF:FE00:400, subnet is 2001:1234:ABCD:5678::/64 [EUI]