Today i’ve installed pterodactyl (https://pterodactyl.io/) on my vserver hosted at netcup.
Since then my ipv6 Routing wont work anymore.

Im Using Debian 11, interface is eth0 on linux

Here is the output of the ipv6 routing table:

root@mail:~#  ip -6 route
::1 dev lo proto kernel metric 256 pref medium
::2 dev wg0 metric 1024 pref medium
2a03:4000:6:739a::/64 dev eth0 proto kernel metric 256 pref medium
fd42:42:42::/64 dev wg0 proto kernel metric 256 pref medium
fdba:17c8:6c94::/64 dev pterodactyl0 proto kernel metric 256 linkdown pref medium
fe80::/64 dev docker0 proto kernel metric 256 pref medium
fe80::/64 dev br-e34bf821906b proto kernel metric 256 pref medium
fe80::/64 dev veth22db3e1 proto kernel metric 256 pref medium
fe80::/64 dev veth5048b60 proto kernel metric 256 pref medium
fe80::/64 dev veth3d0748d proto kernel metric 256 pref medium
fe80::/64 dev veth77f6cc7 proto kernel metric 256 pref medium
fe80::/64 dev veth5504670 proto kernel metric 256 pref medium
fe80::/64 dev veth60c5e5f proto kernel metric 256 pref medium
fe80::/64 dev pterodactyl0 proto kernel metric 256 linkdown pref medium
fe80::/64 dev eth0 proto kernel metric 256 pref medium
default dev eth0 metric 1024 pref medium

when i try to get the ipv6 route for google.de i’ve get the following output.

root@mail:~# ip route get [2a00:1450:4001:811::2003]
local 0.0.0.0 dev lo src 127.0.0.1 uid 0
    cache <local>

Netcup says as Default ipv6 Route : fe80::1

I’ve tried to add a ipv6 routing entry to eth0, no change:
COMMAND: /sbin/ip -6 route add default dev eth0

tried to add default gateway to fe80::1 :
COMMAND: /sbin/ip -6 route add default gw fe80::1
Error: either “to” is duplicate, or “gw” is a garbage.