ipv6calc

ipv6calc gives me an easy way to convert 48-bit MAC address to 64-bit EUI used as interface identifier in IPv6 address:

[root@localhost ~]# ipv6calc --action geneui64 --in mac --out eui64 00:15:F2:BC:03:8C
215:f2ff:febc:38c

Another application is to query the type of an IPv6 address:

[root@localhost~]# ipv6calc -q -i 2001:200:0:8002:203:47ff:fea5:3085
Address type: unicast, global-unicast, productive
Address type has SLA: 8002
Registry for address: APNIC
Interface identifier: 0203:47ff:fea5:3085
EUI-48/MAC address: 00:03:47:a5:30:85
MAC is a global unique one
MAC is an unicast one
OUI is: Intel Corporation

Great, it is found that the IPv6 address 2001:200:0:8002:203:47ff:fea5:3085 is assigned by auto-configuration.