A relatively new authentication method that has been keeping my
attention for some time now is port knocking. Essentially, a firewall
would keep a port closed until it sees a predefined set of traffic. For
example: I want to access port 22 forwarded to my webserver behind a
monowall. To open port 22, I must first "knock" by accessing other
closed ports such as UDP 9876 and TCP 3349. Once the firewall sees these
ports "knocked", it allows access from my IP to port 22.
A finer explanation can be found at: http://www.portknocking.org or
In my wanderings on this method, it <i>appears</i> it would be
relatively easy to implement with monowall. Is there a possibility this
could be added to a future release? It would be great to see! Maybe it
belongs with pfSense instead?
What do you all think?