Debugging Networking problems ??

[Usjes]

Hi,

I would like to know if anyone can point me to a tutorial on network problem debugging or some useful software. I have a wireless network consisting of 3 windows machines (2 XP and one win2K) they are all networked and share an ADSL connection via a Belkin wireless router/ADSL modem. I enabled print and file sharing on all the machines and installed VNC on all of them and had no problems moving data amongst them, printing from any of the machines etc. for a number of months. Recently however the network seem to have fallen apart. Some machines can ping some of the others but none can VNC to any of the others, none of the machines can print via the network and file sharing is flaky.
I have no idea what has changed, I tried rebooting everything but it was of no help. So I would like to know what I can do to debug the problem ?
When I printing failed, I tried VNCing to the machine with the printer attached, when that failed I tried pinging it, when that failed I had no idea what to do. What should the next step be ?

One consistent fact is that none of the machines ever have any problems accessing the internet. This leads me to conclude that if any machine on the network sends traffic to the router to be forwarded to the ADSL connection the router does so successfully, if however they send traffic to the router to be forwarded to another machine on the network it will more than likely fail.
What can I do to debug these problems ?

Thanks,

Usjes.

[mccoffee]

I suggest give each computer a manual ip that way it will be alot eaiser to troubleshoot later on. http://www.speedguide.net/read_articles.php?id=177

After you do the ip's on the machine make sure all are in the same workgroup. On the xp machines if you are using xp's frewall that in control panel firewall advanced that unpnp is allowed to go though ,and file and print sharrng Also Vnc is checked and allowed to go through.

On the router make sure upnp unverisal plug n play is checked ,or manually enter the ports for vnc http://www.portforward.com/english/applications/port_forwarding/VNC/VNCindex.htm Upnp should open the ports to firewall to allow vnc ,or any othe app is being used on the netowrk.

On the xp machines make sure in control panel system remote that you allow the computers to be accessed remotely. if you are running 2k server you might have to chnage your ights/role to add remote admin in group policy editor.