Waiting for VNC to work again.. the basics.

[tbcbbq]

Hi All,
 
My friend had vnc working with adelphia cable and a cable modem and a dlink router on one machine and the other machine was hardwired with a nic and an RJ45 cable.  All he did was to basically move the machine from one cable operator to  another (the viewwer only-server is still in place) and now vnc(the server) refuses to work.  I went to this machine and used it as the server and got into my machine at home (66 miles away) with no problem.  My machine has a different cable provider and is hardwired to a nic with no router or hub or anything inbetween.  When we try to access the server it says "connection timed out".  
 
>From talking to the cable people they are telling me that the firewall is not allowing the connection. I also know that the machine is turned off most of the time and that could very well be the problem and that can be fixed.
 
 I got into the cable modem the other day and it shows vnc setup for ports 5800 and 5900 as it should be. Nobody has messed with this and all we did was to physically move one of the viewers.
 
The server has windows xp sp1 (no preset firewall as far as xp is concerned).  There is antivirus software on the machine but no firewall installed in it.  From the above, I am going to assume that the router is correctly port forwarded to the nic.  Can I assume that this is true?  Nothing was touched software-wise on the server.
 
This is the rest of what I know, no more, no less.  VNC sends a request that goes to the cable modem first.  Adelphia cable told me there was no firewall on the cable modem so there should be no problem there?  
 
Then, the request goes to the router or a hub but not both?  I thought a router was a hub of sorts?   There is a hub that probably has 2 network cables, one for the server and one for the machine in the room upstairs.  From what I know a hub is just a repeater and allows you multiple connections off the same router or cable modem?  There is no firewall on the hub?
 
Then the request goes to nic.  Both the nic and the cable modem have ip addresses.  What the he** is the difference (in plain, understandable English) between a public and a private IP Address  and what accomodations do I have to make for both?  How do I find out which is the public and which is the private ip address?  I know how to do a "ping" and an ipconfig/all to a batch file.  I can also go into the connections tab and add "allowable ip addresses", but which one(s) do I add?  The public or the private or both?  And how?  
 
I need to mention that I have read the documentation that vnc provides and some of it was Greek to me.  I am just starting to learn networking as you have already surmised.  The hardware connections are a no-brainer; it is the software and all its rules that is screwing me over royal.
 
What is really pissing me off is this setup used to work and the guy that did it only took an hour to set it up.  He is no longer available and the burden has fallen on me.  The best idea that i have is to bring the machine home and hook it up to my cable modem, which is hardwired from the modem to the nic and see if it works that way. That tells me then that the problem lies with the router and/or the hub if it decides to work?
 
 I have xp pro, sp1, no firewalls, no router, no hubs or any of that crap to mess with.  I think that is why from the server i could connect to my machine at home. No bs to put up with.  Straight through connection basically.
 
I would appreciate any step-by-step help you could give me as far as what to check and/or troubleshooting. 
 
Thanks much,
 
   Joe

		
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