@AkgunFatih On the Proxmox forum you could have more explanation
your setup seams to be one IP / one network interface
the difference of what you asking is one VM manage the interface, then all your VM/Container are under a virtual network (inside your proxmox which will be design by vmbr1)
Also, to have better performance of your one network internet you could dedicated / passthrough it directly to the VM (pfsense,nethserver,opnsense) in my case is this ethernet
you could find more info here: https://pve.proxmox.com/wiki/Pci_passthrough