Capture network traffic of a Proxmox VM

In order to capture the network traffic that goes through a network interface of a Proxmox VM, do the following:

1. Get the Proxmox VM ID.
2. Get the Proxmox VM interface name.
3. On the Proxmox node that hosts the VM, check that there's a tap network interface named tap<VM_ID>i<NET_INTERFACE_ID>.
4. On the Proxmox node that hosts the VM, run tcpdump in order to capture network traffic to a file:

sh tcpdump -i tap<VM_ID>i<NET_INTERFACE_ID> -n -w <filename>.pcap

Source: https://www.apalrd.net/posts/2023/tip_pcap/