I am using Proxmox with several VLANs for VMs with an ISP that hands out dynamic IPv6 prefixes.
Thus, my router gives router advertisements for different VLANs with their respective prefix. The VLANs are defined on the Proxmox host, where only one VLAN has an IPv4 assigned. So, I can connect VMs to any given VLAN bridge.
I want to make use of IPv6 for the Proxmox host as well (I need to because there is a counterpart that is only reachable via IPv6), but I find no way of doing that: I obviously cannot use a static IPv6, because I cannot predict the dynamic prefixes. For any other machine on that VLAN, I use SLAAC, which works fine for this.
However, I now found that - counter-intuitively - SLAAC is automatically being used if you do not configure an IPv6 address at all (i.e. on all otherwise unconfigured VLAN bridges), but not if you assign a static IPv4 (!) for an interface. This is strange in more than one aspect, since it has the side effect that IPv6 works 'by accident' via the unconfigured bridges, despite they are only there to have VM guests (but NOT the Proxmox host) connect somewhere.
I have tried to add a manual line to /etc/network/interfaces like:
iface vmbr0 inet6 auto
autoconf 1
accept_ra 2
But it does not work since ifupdown2 does not understand 'auto', only 'static', 'manual' and 'dhcp'.
What I would like to have is a way to specify SLAAC for an interface/bridge and have an empty configuration mean "no IPv6". At this time, I cannot do the first and I think that SLAAC "per default" is a risk in itself.
Thus, my router gives router advertisements for different VLANs with their respective prefix. The VLANs are defined on the Proxmox host, where only one VLAN has an IPv4 assigned. So, I can connect VMs to any given VLAN bridge.
I want to make use of IPv6 for the Proxmox host as well (I need to because there is a counterpart that is only reachable via IPv6), but I find no way of doing that: I obviously cannot use a static IPv6, because I cannot predict the dynamic prefixes. For any other machine on that VLAN, I use SLAAC, which works fine for this.
However, I now found that - counter-intuitively - SLAAC is automatically being used if you do not configure an IPv6 address at all (i.e. on all otherwise unconfigured VLAN bridges), but not if you assign a static IPv4 (!) for an interface. This is strange in more than one aspect, since it has the side effect that IPv6 works 'by accident' via the unconfigured bridges, despite they are only there to have VM guests (but NOT the Proxmox host) connect somewhere.
I have tried to add a manual line to /etc/network/interfaces like:
iface vmbr0 inet6 auto
autoconf 1
accept_ra 2
But it does not work since ifupdown2 does not understand 'auto', only 'static', 'manual' and 'dhcp'.
What I would like to have is a way to specify SLAAC for an interface/bridge and have an empty configuration mean "no IPv6". At this time, I cannot do the first and I think that SLAAC "per default" is a risk in itself.
