Hi Rob, perhaps something like this will do: https://gist.github.com/tonusoo/0490bc5cf564689f3999f1de4eef098d On Debian based distributions the dependencies can be installed with "apt install --no-install-recommends python3-pcapy python3-scapy". Pcapy is a wrapper library for libpcap which processes the filter in Berkeley Packet Filter syntax, builds the binary bytecode and eventually sends it to the kernel via the SO_ATTACH_FILTER. Thus, there should be very little impact on throughput or CPU usage. I used a following systemd service to manage the script: root@deb12-1:~# systemctl cat packet-forwarder # /etc/systemd/system/packet-forwarder.service [Unit] Description=Forwards certain packets received on eth0 out from eth1 After=network.target [Service] Type=simple Restart=always ExecStart=/usr/local/sbin/packet-forwarder.py [Install] WantedBy=multi-user.target root@deb12-1:~# Martin
