I would jump on the offer. College kid can do you far more good than harm .. as you'll probably discover.

They can only get into your PC if you share your drives.

On the other hand, if someone really wants to get into your computer, they can.

Just tell them straight up that you don't want them in you computer. Period. I take it that they are somewhat honest or you wouldn't have rented to them.

College kids can be very helpful when it comes to PC-related things...

I don't think it will be a problem. Some people who *try* to connect (network) two computers aren't able. It depends on the networking savvy of your tenants. I guess a little paranoia is a good thing.

There are resources on the web that specifically address the topics of networking security .. which are far too involved to detail in a post .. people write entire books on the subject.

I have a very basic page on network security:

http://radified.com/Security/shields_up.htm

Steve has a good page here:

https://grc.com/x/ne.dll?bh0bkyd2

especially the page on network bondage:

http://grc.com/su-bondage.htm

You can also get some help at the forums at Speedguide.net:

http://forums.speedguide.net/

they have a forum specifically dedicated for 'Computer Security'. DSL Reports also has a forum dedicated to 'Security' in their many forums here:

http://www.dslreports.com/forums

You can find basic info on home networking here:

http://www.howstuffworks.com/home-network.htm

Firewall info here:

http://www.sysopt.com/articles/freesecurity/index.html

Windows 2000 with NTFS gives you more security than W9xRad with FAT32.

There are many sophisticated network scanning programs that allow you to monitor net activity, such as:

http://www.gfi.com/languard/lanscan.htm

and sniffers

https://grc.com/oo/packetsniff.htm

My network buddies say that the best defense comes from setting up a stand-alone Linux box configured with firewall (& maybe a router if you neeed it). You can get in touch with many of them here:

http://www.linuxnewbie.org/cgi-bin/ubbcgi/ultimatebb.cgi

Hackers are actually the most help in this area. I am not a hacker, but know some .. they have 'tools' that allow them to go pretty much whereever they want and do whatever they like .. giood ppl to have as friends. Most of them live in Europe.

If you are concerned about network security, the best defense is to educate yourself. There is a lot of info, but it's not difficult to learn. Or perhaps you want to pick up a book onthe subject:

http://www.amazon.com/ (search 'books' for networking security')

Your use of the phrase 'as high security as seems practical' is entirely subjective. What seems 'practical' to me, may not be at all 'practical' to you .. which is why you should educate yourself.

Personally I feel that, if you don't trust them enuf to stay out of your computer, you probably shouldn't be renting to them.

If you're on a network like you're describing, simply not sharing your drives will probably more than offer enough protection.  However, if you want to take that extra step, you can install ZoneAlarm (firewall).  It's a freeware program that works great.  It will block all inbound and outbound traffic that you do not grant access for.  It's also very easy to set up.

Hi Phenarius--

As a bear of only modest networking brain, I'm sitting here behind a Netgear cable router/switch which I would guess is analagous to what your tenants have.

I would think that if you acquired another one of these (as you suggest), you would use the feed from their switch as your "Internet" input (and they would see the IP address of the Internet side of your router as your "only" IP address visible to them.  You could then have (probably) 256 IPs of your own on your side of the firewall if you wished, and they couldn't reach you at all. 

Call me old-fashioned, but a piece of h/w makes me feel a bit more secure than a s/w firewall.

Good luck!
   -Paul G