Stupid mistake:No more connectivity vmx0 interface after upgrade 24.7.7 to 24.7.11_2

[bjornp]

Just upgraded my OPNsense VM running on a Protectli VP4630 box with VMware ESX 8.0 U3 a few hours ago.
The VM has 5x VMXNET3 virtual NICs. One for each VLAN (WAN, LAN, IoT, Guest and IPTV). So OPNsense does not have to handle VLAN tagging.
vmx0 is mapped in OPNSense to my Guest network, which is the only one not working anymore after the upgrade.
All other interfaces are working fine.
On my vmx0 (guest) network I do get an IP address from the DHCP service on OPNSense.
Pinging the OPNsense gateway is not working. I do see accepted DNS requests coming from a guest network client in the firewall logs, but the requests are not returning anything.
Only change has been the OPNSense upgrade.
I am using Ubiquiti switches and accesspoints.

I have not tested a VM restore yet.

[bjornp]

Just restored the whole VM with version 24.7.7 from the day before the upgrade and guest network is working fine.
Stopped the 24.7.7 VM and restarted the 24.7.11_2 version and guest network is broken again, so the update seems to only break the vmx0 interface.

This issue maybe related to https://forum.opnsense.org/index.php?topic=44531.0, but I am only using untagged interfaces.
ESX does the tagging for the VM. OPNSense has 5 untagged interfaces.
 

[bjornp]

My bad! I was stupid enough to have used the same subnet for Guest as for a new wireguard client subnet a few months ago.
Strangely it was accepted by the previous versions.
After changing the guest subnet all is running perfectly again.

Thanks OPNsense team for this amazing product!!