Proxmox lab network set up: isolated vmbr1

[FAIL]

Never run vulnerable VMs (like Metasploitable) on the same network as your home devices. Always isolate.

Create a bridge in Proxmox

Proxmox GUI → Node → Network → Create → Linux Bridge

vmbr1 settings

# Name:         vmbr1
# IP address:   leave empty  ← important!
# Gateway:      leave empty
# Bridge ports: leave empty  (do not attach a physical NIC)
# Comment:      lab-isolated

[ TIP ]

vmbr1 is purely a virtual switch. No IP needed on the host — Kali and the target VMs sort out their own addresses.

Checklist

vmbr1 created without an IP address and without bridge ports
Kali has two NICs: vmbr0 (internet) and vmbr1 (lab)
Target VMs have only vmbr1 as their NIC
Kali can ping Metasploitable on 10.10.10.20
Metasploitable can NOT reach the internet

Reflection

Add here what you ran into, what was tricky, and what the next step is.