IPv6 FIB frequent add/remove messages (dual-stack)

["B.R." <reallfqq-debian@yahoo.fr>]

Hi,

I own a hosted dedicated server and my hosting provider just reported me my server is continuously removeing/adding entries to the FIB table of their router.

I checked my interfaces configuration, and restarted he network interface to be sure the right configuration was applied.

Here is the reported spam:

Dec 12 19:43:02.567:     [base] 2A00:C70:1:213:246:aaa:bbb:0/128'0A FIB remove

Dec 12 19:43:03.283:     [base] 2A00:C70:1:213:246:aaa:bbb:0/128'0A FIB add src
Dec 12 19:43:06.283:     [base] 2A00:C70:1:213:246:aaa:bbb:0/128'0A FIB rem src
Dec 12 19:43:06.283:     [base] 2A00:C70:1:213:246:aaa:bbb:0/128'0A FIB remove

Here is my interface configuration:
auto eth0
iface eth0 inet static

        address 213.246.aaa.bbb
        netmask 255.255.255.0
        broadcast 213.246.aaa.255
        network 213.246.aaa.0
        gateway 213.246.aaa.1

iface eth0 inet6 static
        address 2a00:c70:1:213:246:aaa:bbb:0
        netmask 96
        gateway 2a00:c70:1:213:246:aaa::1

The IPv6 configuration has been checked against the hoster guidelines and is correct.

One of the strange things is that the reported IP address mask is not the one I set up.

I also have some stuff running on top of my router, one the notable things is a DNS.

Would it be some IP-configuration related problem only or could the trouble come from some higher-level program?

I am not familiar at all with those routing tables and the IPv6 configuration trouble.
What am I doing wrong?

---
B. R.