I wrote up a detailed blog post on how to run knoppix simultaneously with Debian or for that matter any distro of Linux without using any virtualization software.
Also instead of cloop i used squashfs.
Cisco ASA 5520 Adaptive Security Appliance
$42.56
Check Point L-71 6 Port Gigabit Enterprise Firewall
$34.99
Ubiquiti Networks USG Unifi Security Gateway Router/Firewall
$29.95
NetGate SG-2440 with pfSense Plus Console GNU Router Firewall Security Appliance
$69.99
Fortinet Fortiwifi 60D FG-60D Security Appliance Firewall / VPN w/ AC Adapter
$34.97
Ubiquiti Networks UniFi Security Gateway - White (USG-3P)
$49.00
OPNsense six-port Gigabit router/firewall on Lanner FW-7535 hardware
$69.00
$120.00
Fortinet FortiGate 60F | 10 Gbps Firewall Security Throughput (FG-60F)- Open Box
$381.99