Proxmox 7.0-8 cannot access VMs that use vmbr0

[Tacioandrade]

Good afternoon friends! I'm creating this post because I've been using Proxmox since 2.3 and it's the first time I've gone through this!

I have a Proxmox that has just been installed by the official iso in version 7.0-8 and I have as a gateway to this Proxmox, a pfSense 2.5.2 virtualized within Proxmox itself (I have several environments that way, but only this one presented this problem).

On Proxmox I have vmbr0 with IP 10.10.10.253/24 and VLAN Aware activated, so pfSense can create virtual LANs for Unifi, in addition to vmbr1 and vmbr2 that serve as pfSense's WAN.

pfSense is running with IP 10.10.10.1/24 and working perfectly both the LAN and the other VLANs of Unifi as Visitors.

The problem I'm facing is that Proxmox 10.10.10.253 can't ping 10.10.10.1, just like the reverse happens! To test I uploaded a Linux VM with IP 10.10.10.200/24 and the same happens, the PVE cannot access the VM, but from the LAN (any computer), it can access PVE and pfSense normally.

I'm having problems because due to this difficulty, I can neither monitor the PVE through Zabbix nor update it, since it can't access the gateway at all.

I thought the problem could be the PVE firewall, but I checked and it is disabled in Datacenter, PVE and VMs.

I would appreciate any help you can give to resolve this issue.

PS: Hardware Checksum Offloading is Disable on pfSense

 

[Dunuin]

what does your /etc/network/interfaces look like?

Maybe its a vlan problem? If you add your proxmox IP directly to the bridge it will only send untagged packets.
If you want PVE to be sending packets to a specific vlan, you could add an additional vlan interface like this, if you for example want pve to be part of vlan 100:

auto vmbr0.100
iface vmbr0.100 inet static
    address 10.10.10.253/24
    gateway 10.10.10.1