Installation script breaks IPv6 on VPS

[giannoug]

It seems that running the installation script on a VPS (using a host-provided template named "Debian 10 64bit (latest)") breaks IPv6 networking. After a bit of troubleshooting I discovered that the default route is deleted.

This is ip -6 route | grep eth0 before the script installation (and right after reinstalling the Debian template):

2a02:xxxx:x:xxx::/64 dev eth0 proto kernel metric 256 pref medium
fe80::1 dev eth0 metric 1024 pref medium
fe80::/64 dev eth0 proto kernel metric 256 pref medium
default via fe80::1 dev eth0 proto ra metric 1024 expires 1596sec hoplimit 64 pref medium

This is the output after installing the VPS script:

2a02:xxxx:x:xxx::/64 dev eth0 proto kernel metric 256 pref medium
fe80::1 dev eth0 metric 1024 pref medium
fe80::/64 dev eth0 proto kernel metric 256 pref medium

The default route is lost, so VPS can't connect to any IPv6 address:

# ping -6 google.com
connect: Network is unreachable

[Ysurac]

Please use the template.
This may be related to the firewall, shorewall6, configuration. I would need to know the VPS provider to test.

[giannoug]

I use the template "Debian 10 64bit (latest)" I mentioned. IPv6 works at first and breaks after running the VPS install script (this repo). By template I mean the rootfs in SolusVM / VPS language. Here's the provider if you want to test: https://top.host/vps-hosting-options?pid=129