Hi there,

Finally I got the answer from google search, refer to https://blog.flyingpenguintech.org/2017/12/ipv6-with-macvtap-and-libvirt.html
This is expected. With trustGuestRxFilters="yes", ipv6 works well.

# virsh dumpxml vm1  --xpath //interface
<interface type="direct" trustGuestRxFilters="yes">
  <mac address="52:54:00:f5:0d:b1"/>
  <source dev="eno1" mode="bridge"/>
  <target dev="macvtap1"/>
  <model type="virtio"/>
  <alias name="net0"/>
  <address type="pci" domain="0x0000" bus="0x01" slot="0x00" function="0x0"/>
</interface>



BR,
Yalan

On Tue, Jul 11, 2023 at 9:48 AM Yalan Zhang <yalzhang@redhat.com> wrote:
Hi there,

I have a question regarding direct type interfaces. Would someone be able to take a look at it?
When I start 2 VMs on the same host with interface "direct type + bridge mode", just as below:
 <interface type="direct">
  <mac address="52:54:00:9e:7b:51"/>
  <source dev="eno1" mode="bridge"/>
  <model type="virtio"/>
</interface>

The 2 VMs can connect to each other via ipv4, but can not connect to each other via ipv6.
Maybe it's related to some kernel parameters, but I don't know how to debug. 
Is there anyone who can help me? 
Thank you!


BR,
Yalan