The first time I used Proxmox I had problems because my new cloned virtual machines where all taking the same private IP address from the DHCP server.
I couldn’t connect via ssh or anything else, so I’ve looked on the Proxmox Wiki, discovering that I have to follow some steps.
Unfortunately the last step that I’m describing here was not in the Wiki.
Change name of the VM
Login to the new clone VM
sudo nano /etc/hostname
sudo nano /etc/hosts
Change Mac address
Shut down the VM and from the Proxmox admin panel remove the network card, then add it again. The phisical address will change.
Change SSH keys
Turn on the VM and run.
sudo rm /etc/ssh/ssh_host_*
Change machine id
This step was not described in the Wiki and I had to google a little bit, luckily I’ve found this post on the Proxmox forum.
sudo rm /etc/machine-id
That’s all! Now your DHCP server should give a different IP to all your different VMs.