[SOLVED] Trouble with IPv6 config

[chrisb1]

Hi,
on a fresh installation of proxmox I'm struggling a bit with the IPv6 configuration. Hopefully someone can help me out.

My setup (full interfaces config at the bottom):
eno1: used only for proxmox management on an access port on my switch which is associated with my management VLAN.

• I want to use DHCP for IPv4 and IPv6 with static reservations on my pfSense installation (pfSense is completely separate and not virtualized).
• I want to turn off SLAAC, because I want to setup dedicated allow-rules for proxmox in my management VLAN also for IPv6 and that won't work if I have to deal with SLAAC (--> firewall has no knowledge of those addresses)
• static IPv6 is unfortunately no option as my ISP decided to hand out new prefixes everytime I reconnect

eno2: used for the vmbr0, which is the bridge for all my VMs (no problem here)
eno3 & eno4: not connected

The problem:

• DHCPv6 works fine and proxmox pulls the static assigned IPv6, BUT from time to time it also pulls an additional dynamically assigned IPv6. Looking at the pfSense logs it turns out, that the proxmox host contacts the DHCP with a different DUID?! in /var/lib/dhcp/ I have one one dhclient6.lease which contains the expected DUID. Where does the other one come from?? How can I stop this? --> The unexpected IPv6 from DHCPv6 appears and disappears from time to time without interaction, therefore I have no clue, what triggers this behavior
• It seams like I cannot deactivate SLAAC, even though the option "autoconf 0" should achieve this from what I understand?! (At least, that's how I understand this site: https://manpages.debian.org/testing/ifupdown/interfaces.5.en.html)

full /etc/network/interfaces:

auto lo
iface lo inet loopback

auto eno1
iface eno1 inet dhcp
iface eno1 inet6 dhcp
    autoconf 0 ### <-- this seams to have no effect?!
#Port for Proxmox Management

iface eno2 inet manual
#Port for VMs

iface eno3 inet manual
iface eno4 inet manual

auto vmbr0
iface vmbr0 inet manual
    bridge-ports eno2
    bridge-stp off
    bridge-fd 0
    bridge-vlan-aware yes
    bridge-vids 2-4094
#VLAN aware Bridge for VMs

 

[chrisb1]

Just in case anyone runs in the same problem: After approx. one day of waiting (no further reconfiguration or any action) everything works fine: no more SLAAC and only the expected address from DHCPv6.
--> The system seams to need some time to get used to the network