No IP for Migrated VM’s in 25.04 (Fangtooth)

It seems that I have the same problem. Migration from 24.10.2 to 25.04-RC1. I recreated an existing VM as described in the release notes and used the bridge (not MACVLAN) interface that i used in 24.10.2 before (bond0 > vlan0100 > br0100). Under 24.10.2 i used the virtio interface type.

I have no firewall enabled on the guest, in my case its an Ubuntu 24.04.2 LTS.

The interface appears in the guest as enp5s0. But if i set the IP/subnet, its very strange: I can ping hosts in the bridged network, but hosts from other networks can not ping the guest. It seems to me there is an firewall/routing thing going on…

It can be an problem with the routing table at the guest. If the physical interface names changes, its possible that an (static) route does not work anymore. In my case this shows “ip route“:

After rollback to 24.10.2 it works fine again.

Can you check the routing table on the guest?

On 24.10 Default for a VM is to get their own IP (VirtIO; own MAC address).

I cannot get that in 25.04 after migrating. I haver tried “Default” and “MACVLAN” (like “NIC: eth0 (MACVLAN)”, but I never get it visible on my network

When creating new VM on 25.04 with MACVLAN I get the same as on 24.10: own MAC address and IP. This is good.

Remark: I find it strange in 25.04 to find the network “default” to be a bridge to host.. Too much container thinking; makes less sense for VM’s for which you default want a separate IP

Are you manually changing the system to use MACVLAN on 24.10? That was not an option before AFAIK.

Did you try using a bridge instead? Thats the only supported configuration yet for this scenario.

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