IP-Adresse und Gateway an OVH API abfragen:

/vps                                # List available services
/vps/{serviceName}                  # Get this object properties
/vps/{serviceName}/ips              # Ips associated to this virtual server
/vps/{serviceName}/ips/{ipAddress}  # Get this object properties

/etc/network/interfaces.d/51-cloud-init erstellen:

auto ens3
iface ens3 inet6 static
mtu 1500
address 2001:1337:6969:1100::123
netmask 64
 
# routing
post-up /sbin/ip -6 route add 2001:1337:6969:1100::1 dev ens3
post-up /sbin/ip -6 route add default via 2001:1337:6969:1100::1 dev ens3
pre-down /sbin/ip -6 route del default via 2001:1337:6969:1100::1 dev ens3
pre-down /sbin/ip -6 route del 2001:1337:6969:1100::1 dev ens3

Netzwerkdienst neu starten. Ggf. Server neustarten.

sudo systemctl restart networking.service
sudo reboot