SlackBuildsOrg/network/ipv6calc

ipv6calc is a small utility written in C to manipulate (not only) IPv6
addresses. It converts a given IPv6 address into compressed format, or
into the same format shown in /proc/net/if_inet6.

This utility was also used in the past to extend features on
network-functions-ipv6 library, used by initscripts-ipv6.

To enable IP2Location support you will need to install the optional
dependency ip2location-c first, and then pass:

  IP2LOCATION=yes

to this Slackbuild.