Disclaimer: I am not sure if this is a question for the Pi StackExchange site, but I am posting it here anyway. If it should be moved elsewhere, please do not hesitate to suggest where it should be moved to.
I only just setup my Pi last night. I have configured very little as of yet.
My home intranet, at the moment, has two computers connected to a Belkin router, which in turn is connected directly to the internet via a cable modem. - my RPi is wired directly via ethernet cable and my laptop via wireless (Windows 7 on laptop).
I can access my Pi console via SSH and Putty on my laptop.
How can I ensure that the Pi only allows connections into it from my laptop and my laptop alone? Perhaps this has something to do with the MAC address?
I ask this question because I can configure my Belkin router to only accept wireless connections from specific MAC addresses. (Therefore one more level of security - besides WPA encryption on wireless access point). So if someone wanted to access internet through my router, they not only need to crack the WPA password, but they also need to spoof my MAC address (presumably).
I would like to do something similar, specifically for the PI. If someone were to hack the router, it would be nice if the PI restricted access to itself from any computer other than one I have specified (my laptop).
If it is not already evident, I am quite a noob when it comes to network security (but eager to learn :) ).
Not sure if this is relevant or not, but eventually I will have the Pi connected to the router via an Edimax USB adapter: http://www.edimax.com/en/produce_detail.php?pd_id=347&pl1_id=1.
In the near future, I also intend to buy one or two more Pi's and have them communicate with each other via the router in my home network.