I have a problem I've never seen before.

First the layout:

I have multiple LANs (2 maybe 3) that I want to connect together via VPN tunnel. The goal is to provide remote back up of critical files in an automated fashion for each location using Ready NAS file servers and to allow other benifets of connected networks.

To do this I need to change the default IP schema, 192.168.0.1, to to something that will accomodate multiple subnets.

The problem is that when I change the 3rd byte to something other than 0 the PC's on the network stop talking to one another. I can't ping from PC to PC. The PC's will ping other devices on the network, printers, color Copier/printers, and even the Mac computers and NAS devices. For the most part this would not cause a problem except that one PC needs to be able to output graphics files to a PC based RIP.

I have reset the router to Factory default and changed to a back up router and both act the same. Every thing is fine if the IP is 192.168.0.1 but stops working if I change it to 192.168.x.1 where x is other than 0.

I am under the understanding that for multiple subnets I can't use a 0 for the third IP byte if my SN Mask is 255.255.(0-254).0 only if it is 255.255.255.0 (single subnet) .

If your first question is did I remember to change the IP on the respective PC's each time? The answer is yes.

Anybody seen this before and/or have an idea how to fix?

Any Wild A... Guesses?

Did my post make sense?

Does it appear that I am understanding subnets correctly for the application I need?

Sounds like you're not understanding subnets correctly. Here are a number of links that may help you:

viewtopic.php?t=3336

viewtopic.php?t=2880

viewtopic.php?t=2881

Keep in mind, for hosts residing in different subnets, communication must go through a layer 3 device (router). So by changing the third octet, you're changing the IP subnet that your hosts reside in... so it's not going to be quite as simple as you think.

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Reasonably un-nerdy blog:
americanwerewolfinbelgrade.wordpress.com/

Moved to Tech Discussions.

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Reasonably un-nerdy blog:
americanwerewolfinbelgrade.wordpress.com/

Thank you for the links, I will look them over shortly.

I think I muddled the question I first need answered with too much of the overall plan. Let me re-state what I need to figure out first.

With my router (Netgear FVS114) in factory default all is good.

(IP= 192.168.0.1 SN Mask 255.255.255.0)

The problem I have is when I change the IP to 192.168.1.1 with no change to the SN Mask. Then ipconfig -release and then ipconfig -renew on each PC causes them to assume the new IP as issued by the DHCP server. 192.168.1.2, 192.168.1.3, 192.168.1.4, & 192.168.1.5 respectivly as you would expect. But they (the PC's) do not communicate with each other like they did before. Changing the router LAN IP back to 192.168.0.1 and renewing all the machines IP's results in all of them talking again.

It is only the PC based machines that stop talking, the Macintoshes and various printers and other devices all continue working correctly with either IP assignment.

What I really don't get is that when the PC's are not communicating with each other they (the PC's) still communicate with the non PC machines, printers, plotter, and File servers.

Like I said originally This is not a problem except for one of the PC's is a postscript RIP that the other pc's need to send graphic files to.

I'm off to check out those links.

Maybe you can elaborate more on what you are trying to do and what mask you are actually using or trying to use .

Ah, ok... It's starting to sound like more of a windows issue... I don't use windows so I'm not really familiar with those ipconfig commands you ran... Are you sure they clear out everything and start fresh? Perhaps you could try "repairing" the connection or whatever they call it.

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Reasonably un-nerdy blog:
americanwerewolfinbelgrade.wordpress.com/

Those are DOS commands.

Typically they work just like restarting the machine as far as tcpip is concerned. of course nothing beats a cold boot for ensuring everything is reset. My results are the same either way.

RAM,

The situation you described is rather unusual. Some suggestions that I can give to you are:

-Making sure windows firewalls are disabled in every PC.
-Restart the PC even though I believe you already did.
-Try to assign static IPs instead of getting it from the router's DHCP. I doubt this is the problem, but hey who knows...since you are already stuck, everything might be possible right?

Good luck

Jet,

I already did those things. But I am going to double check them any way. At this point who knows. Thanks for the suggestions.