CentOS - Jul 2017 - Still fighting the IPv6 client dying...

Well, we're still fighting it, and one thing I've discovered that I find
extremely odd: the IPv6 lease file. On my C7 workstation, if I grep -c
lease6, I see 5 leases; on a C6 server, I see 9, and in the last few days,
I saw my box - they mass restarted the IPv6 clients everywhere yesterday,
because a good number of systems had lost the client.

Can someone explain why there would be more than, say, 2 or 3 lease6's in
the least file?

        mark