VPN file sharing problems

I was posting in this thread, but it was getting a little long and a lot has changed, so I thought I would open a new one.

I have a VPN tunnel established between my location in PA and our other location in Chicago using 2 D-Link 804HV's. The tunnel is established and has been solid for about a week. The problem is when I attempt to access the shares on the remote PC's or when performing a RDC. Please keep in mind, that I had this VPN working perfectly when the 2nd VPN router was at my house about 10 miles away.

I can view all the shares by typing the IP address into an Explorer address bar. I can navigate through all the folders and get down to viewing the individual files. The problem comes when I attempt to do anything with the files, such as copy them to my PC or view their properties. Sometimes Explorer locks up and other times I receive a message stating that the network path is no longer valid. I can then immediately go back to another explorer window and navigate right back to the PC's shares.

The other problem is that I receive a black screen when attempting a RDC. Everything I read about this problem points to the MTU value. I performed the recommended command of

ping ipaddress -l 1500 -n 50 -f

Sometimes everything is fine and other times I receive the message "Packet needs to be fragmented, but DF sent ". I attempted to lower the MTU value in the D-Link, but the only setting for MTU applies under the WAN menu and didn't change anything.

I am, however, able to access their VPN router from my location with no problems.

Running a pathping, I am finding losses at two different places of 100% if I ping by the WAN address given to the router by the ISP. If I pathping directly to the PC (192.168.0.56) I don't have any loss. I have contacted AT&T about line quality problems. They sent out a tech, who apparently placed a DSL filter on the entire building and was able to get everything straightened out, but I'm not so sure. (I wasn't there, since I work in the PA office and the Indiana office is the one with the problem). I wasn't able to access their router consistently until the tech had finished his work.

Why would I be able to access the router....everytime....but not the PC's behind the router??

Can someone help me??? Thanks!

Edit-> I have also attempted to physically dial down the MTU setting on the NIC using DRTCP and had no luck.

 

In many ways it is easier to access a router than grab files via a windows share. Mainly because you have less of a journey to get to the router, but also because the router's application will be designed for a WAN link where bandwidth is at a premium, whereas Microsoft file sharing is designed for a LAN where bandwidth is plentiful.

However, I wonder if the problem is the route back from the remote PCs. Are the remote PCs in the same subnet as the internal side of the VPN router at the remote site? Have you set up any static routes at the remote site, to tell the PCs there how to return packets they receive. It may be that the remote PC are having problems discovering a route back to you with their response traffic.

In my experience it is common to spend a lot of time working out how to get packets to a remote location, and overlook the fact that the remote systems have to be able to find a route back to you if a successful communication is to be set up.

I'd suggest you try entering static routes to your network via the VPN, at least at the gateway router for the remote PCs.

 

Yes, both networks are on the standard 255.255.255.0 subnet. The thing that gets me about the entire situation, was that the VPN was functioning when I was testing at my house. I would consistently transfer 1+ GB files over the VPN ever night and never had a problem.

When you say, "I'd suggest you try entering static routes to your network via the VPN, at least at the gateway router for the remote PCs. " are you talking about the standard route add command, or to forward traffic between the two servers inside the VPN routers.

Thanks ReggieB

EDIT -> I've been messing around with the route add command for awhile and I can't seem to get it to function properly. Here is the setup

My PC's IP = 192.168.1.104
My PC's Subnet = 255.255.255.0
Gateway = 192.168.1.1

Remote Location Server IP Address = 192.168.0.56
Remote Server's Subnet = 255.255.255.0
Remote Server's Gateway = 192.168.0.1


I've tried about 100 combinations and can't seem to get something that works. I would think the command would be:

route add 192.168.0.56 mask 255.255.255.0 192.168.1.0 but apparently that doesn't work. Shouldn't that command tell my PC to direct all traffic bound for the remote server, on that subnet mask, through my local router?

Can someone help me with the proper syntax for the command to set up the route between the two locations? When I finally get this route set up, will the route effect the way my PC interacts with my LAN?

Thanks!

 

The route add would be:

Code:

ROUTE ADD 192.168.0.0 MASK 255.255.255.0 192.168.1.1

192.168.0.0 is the network address. So 192.168.0.0/255.255.255.0 is all addresses between 192.168.0.1 and 192.168.0.255 (the last being the subnet broadcast address). So the route add is telling the system to send all traffic for 192.168.0.x IP addresses to the router at 192.168.1.1 to sort out.

However, if your network is as simple as a single subnet and one router at each end of the tunnel, then I may be leading you up a blind alley. I assumed you had a larger central network that you were connecting into.

If you only have one router and that is providing the VPN, then the router should be able to sort out all the routing automatically. If you have one router acting as the main internet router, and a different router providing the VPN, then static routes could still be the solution.

 

There is just one router on each end which is the D-Link 804HV. Other than that, there is a modem on each end, one for the DSL and the other for the T1 and a switch. Pretty simple setup.

I'll try the route add command and see what happens. Any other ideas on what the problem might be?

 

I set that up on both sides of the VPN, here and in Chicago and still have the same problem. I can access the shares and view their properties, but cannot transfer files. When I try to copy the file and paste it to my machine, I can see the "Copying" window pop up and the icon of the file is placed on my desktop and then it just sits there. About 60 seconds later I get the following message:

"Cannot copy filename: Cannot read from the source file or disk "

I saw something about adding a -MTU value to the route add command. Is that possible?

EDIT -> Here is something new. I just attempted to copy a file from my PC to the remote server and got the following:

Cannot copy filename: The specified network name is no longer available.

Here is the weird part.....After I received the error message, I see that the file was actually copied and is on the PC in Chicago. I was also able to delete the file with no problems. Now I'm really confused