Hi everyone,
I'm fighting the well known (multiple older threads in this forum) "Windows Server VM with IPv6" battle on my setup. To sum it up:
VM A:
- VM with Windows Server 2022 is getting no IPv6 (SLAAC) when using VirtIO NIC
- when using emulated E1000, machine gets an IPv6 address and IPv6 works in both directions
VM B:
- VM with Windows Server 2022, also using VirtIO NIC type, does get an IPv6 and can communicate in both directions
- only difference to VM A is that A is on "machine pc-q35-7.2", while B is on "-5.0"
I'm not daring to modify the machine type just for trials. Do you think this might make a difference to the issue?
So I'm working on VM A and leave VM B alone. What I have tried:
- set "multicast_snooping" to "0" on the Proxmox network bridge (does this need a reboot of Proxmox to work?) -> no change
- disable all "offloading" features on the adapter within the Windows guest -> no change
- change NIC to emulated E1000E -> works immediately, IPv6 both directions
Now I've setup a third machine:
VM C:
- VM with Windows Server 2025 not on Proxmox, but on TrueNAS (should be a similar virtualization engine, right?)
- VM with VirtIO NIC does get an IPv6, but can only communicate outbound, not inbound (not even PING)
And now the unexpected part:
On TrueNAS, there is a parameter "trust_guest_rx_filters" that can be checked while creating the virtual NIC. It is disabled by default, but once you enable it, IPv6 works on the Windows guest in both directions, even with NIC type VirtIO.
So my question: Can I set the flag "trust_guest_rx_filters" on Proxmox as well? If not in the UI, perhaps in some ini file?
Regards
I'm fighting the well known (multiple older threads in this forum) "Windows Server VM with IPv6" battle on my setup. To sum it up:
VM A:
- VM with Windows Server 2022 is getting no IPv6 (SLAAC) when using VirtIO NIC
- when using emulated E1000, machine gets an IPv6 address and IPv6 works in both directions
VM B:
- VM with Windows Server 2022, also using VirtIO NIC type, does get an IPv6 and can communicate in both directions
- only difference to VM A is that A is on "machine pc-q35-7.2", while B is on "-5.0"
I'm not daring to modify the machine type just for trials. Do you think this might make a difference to the issue?
So I'm working on VM A and leave VM B alone. What I have tried:
- set "multicast_snooping" to "0" on the Proxmox network bridge (does this need a reboot of Proxmox to work?) -> no change
- disable all "offloading" features on the adapter within the Windows guest -> no change
- change NIC to emulated E1000E -> works immediately, IPv6 both directions
Now I've setup a third machine:
VM C:
- VM with Windows Server 2025 not on Proxmox, but on TrueNAS (should be a similar virtualization engine, right?)
- VM with VirtIO NIC does get an IPv6, but can only communicate outbound, not inbound (not even PING)
And now the unexpected part:
On TrueNAS, there is a parameter "trust_guest_rx_filters" that can be checked while creating the virtual NIC. It is disabled by default, but once you enable it, IPv6 works on the Windows guest in both directions, even with NIC type VirtIO.
So my question: Can I set the flag "trust_guest_rx_filters" on Proxmox as well? If not in the UI, perhaps in some ini file?
Regards