[CLUE-Tech] proper setup of NAT

[Roy J. Tellason]

On Tuesday 03 August 2004 12:55 am, Mike wrote:

> After remaking the firewall floppy, I had a little trouble getting the ports 
> open that I wanted (22 and 25). So to debug this I did a port scan using the 
> site at www.auditmypc.com.

Interesting site!  It found exactly two ports open on my firewall,  one of 
which was for ftp control (but not data),  which would explain some of the 
attempts I've seen showing up in the logs,  and the other one was nearby (21 
and 22 if I'm remembering right),  I forget what they described that one as 
but it's what I use here for SSH.

> So someone in China or Korea is trying to log into my machine that is
> behind the firewall.

I see bunches of that stuff show up in the logs here.  Usually there will be 
just one unsuccessful attempt from any given system,  but one guy thought 
banging on the door a bunch would matter (it didn't) and tried 20-some-odd 
attempts in the space of a couple of minute.  No matter...

<...>

> In short, what should I check or change to make sure these knuckleheads
> don't get in?

I'm wondering about what I might need to change to have those ports not show 
as open from the outside,  while still letting them work from the LAN here.  
I guess a look at my firewall rules is in order.