PVE 9 IPV6 forward enable

1. Enable IPv6 forwarding:

echo "net.ipv6.conf.all.forwarding=1" > /etc/sysctl.d/99-ipv6.conf

2. Accept RAs even while forwarding:

echo "net.ipv6.conf.all.accept_ra=2" >> /etc/sysctl.d/99-ipv6.conf
echo "net.ipv6.conf.default.accept_ra=2" >> /etc/sysctl.d/99-ipv6.conf
echo "net.ipv6.conf.vmbr0.accept_ra=2" >> /etc/sysctl.d/99-ipv6.conf

3. apply

sysctl --system