IPv6 "no route to host"

I'm not that familiar with Linux and don't have a Linux system for comparison, but it looks as if there's no default route, which would explain why you can't reach the internet. Maybe someone else can chime in.

Does ping -6 fe80::1%eth0 work? (if fe80::1 is your gateway)

ip -6 route seems to be missing a default route, which is in my case

default via fe80::1 dev eth0 metric 1024 onlink pref medium

Just in case try the rescue system, which is a "cloudinit" configured GRML live Linux system. It should have IPv6 correctly configured and you should be able to connect out and in with IPv6. The Netcup firewall is automatically deactivated while the rescue system is activated, so that's one less thing to worry about. If the rescue system has working IPv6 connectivity, you can be sure that the problem is something under your control.

It looks like you are missing the default route and you can communicate only inside your network:

Linklocal-Version
sudo ip -6 route add default via fe80::21c:73ff:fe00:99 dev eth0

Or if you got a default gateway from Netcup (value from ip neigh)
sudo ip -6 route add default via 2a0a:4cc0:0:1000::1 dev eth0

As others already said, the default route for IPv6 is missing (at least). As a reference I can supply my working config from a Rocky Linux 8 system for ifcfg-eth0 (some private informations masked out) - see IPV6_DEFAULTGW:

BOOTPROTO=none
DEFROUTE=yes
DEVICE=eth0
GATEWAY=152.53.x.y
HWADDR=7a:c6:w:x:y:z
IPADDR=152.53.x.y
IPV6ADDR=2a0a:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx/64
IPV6INIT=yes
IPV6_AUTOCONF=no
IPV6_DEFAULTGW=fe80::1
IPV6_FORCE_ACCEPT_RA=no
NETMASK=255.255.252.0
ONBOOT=yes
TYPE=Ethernet
USERCTL=no
IPV6_DEFAULTDEV=eth0

You should go back to yast again and try to enter the IPV6 default gateway.

Fascinating. Have you tried telling it what interface to use?

Zitat von jdeisenberg

but not traceroute

You should at least use options -6 -n though I would recommend the more modern tool mtr. It's normal that routers in the chain silently drop ping requests because they have better things to do than to respond to ping requests

Working here now via IPv6!

Yes, I can confirm IPv6 connectivity too!

Following this document https://doc.opensuse.org/documentation/…meters-advanced, IPv6 seems to be an „advanced“ feature …