Comment 14 for bug 1856064

Connections w/o the option:
====================

Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp6 0 0 :::6800 :::* LISTEN 2856080/ceph-osd
tcp6 0 0 :::6801 :::* LISTEN 2856080/ceph-osd
tcp6 0 0 :::6802 :::* LISTEN 2856080/ceph-osd
tcp6 0 0 :::6803 :::* LISTEN 2856080/ceph-osd
tcp6 0 0 fd01::2:6789 :::* LISTEN 2855692/ceph-mon
tcp6 0 0 fd01::1:6802 fd01::3:45354 ESTABLISHED 2856080/ceph-osd
tcp6 0 0 fd01::1:33368 fd01::3:6800 ESTABLISHED 2856080/ceph-osd
tcp6 0 0 fd01::1:42210 fd01::15f6:1bc9:22:6789 ESTABLISHED 2855692/ceph-mon
tcp6 0 0 fd01::1:33338 fd01::3:6800 ESTABLISHED 2855692/ceph-mon
tcp6 0 0 fd01::1:57248 fd01::3:6804 ESTABLISHED 2856080/ceph-osd
tcp6 0 0 fd01::1:48840 fd01::3:6802 ESTABLISHED 2856080/ceph-osd
tcp6 0 0 fd01::1:54172 fd01::3:6803 ESTABLISHED 2856080/ceph-osd
tcp6 0 0 fd01::1:38900 fd01::3:6789 ESTABLISHED 2856080/ceph-osd
tcp6 0 0 fd01::1:6803 fd01::3:47868 ESTABLISHED 2856080/ceph-osd
tcp6 0 0 fd01::1:38868 fd01::3:6789 ESTABLISHED 2855692/ceph-mon
tcp6 0 0 fd01::2:34342 fd01::3:6800 ESTABLISHED 81962/ceph-mgr
tcp6 0 0 fd01::2:48000 fd01::15f6:1bc9:22:6789 ESTABLISHED 81962/ceph-mgr

We can see that there are connections opened from the floating IPs.

How to configure the option by hand
===================
Just add preferred_lft 0 flag when you add a floating ip address to an interface
sudo ip -6 addr add fd01::1/64 dev vlan10 preferred_lft 0