Office VPN - Viewing other machines

[C.J]

Today I've setup a VPN at the office and logged in from home to test. I can connect fine, so I know the username/password etc are correct, and the router can see the incoming connection.

The problem is, I can't see any PCs/shared folders in the office (and the office can't see my home machine). I've tried to connect to them using their LAN IPs (\\192.168.1.40 or \\computername) but nothing is found.

Am I missing something really obvious when setting up a VPN?

Router: Draytek Vigor 2830
Home IP range 192.168.1.x
Office IP range 192.168.1.x

 

[H182]

Probably because the networks are on the same IP range. If you search for 192.168.1.10 for example at home, it'll be looking on your home network rather than work. Change your home to 192.168.2.x and try it then.

 

[rdoxenham]

Yes, it's exactly because the networks are the same subnet. In the most basic sense, your computer has a 'routing table', i.e. 'which device do I use to connect to a given network'. When you connect to a VPN, your computer creates a VPN interface and sets up a route so that all traffic to the VPN network is forced to go via the VPN interface.

Your problem is that you already have a route for the 192.168.1.0/24 network (likely the DEFAULT route), and therefore you VPN interface won't be used where you expect it to. As above, remove the conflict and your routing table should take care of the rest. Set your home range to a different pool, but ensure that you don't just change the DHCP pool... you HAVE to set the router to be in the same pool too, otherwise you'll lose all access to your router (the routers IP will be out of subnet).

 

[C.J]

Change your home to 192.168.2.x and try it then.

Yes, it's exactly because the networks are the same subnet.
..........................
Set your home range to a different pool, but ensure that you don't just change the DHCP pool... you HAVE to set the router to be in the same pool too, otherwise you'll lose all access to your router (the routers IP will be out of subnet).

Right ok, so I've set my home network to 192.168.2.x, but it still doesn't show the PCs/folders when on the VPN.

Looking at the router, my VPN connection inbound is showing as "192.168.1.101/32" The 192.168.1.101 is the static IP I assigned to the user, but what's the /32? Is that effecting it?

HOME:

WORK:

 

[rdoxenham]

No, don't worry about the '/32', a '/32' is a total mask, but to simplify, it's used to represent a single IP address, e.g. the IP address of your client on the VPN.

I assume, 192.168.1.101 is your IP address on the remote network? How have you set this?

Your router should be able to route packets between the two subnets for you, as your local machine will have the default gateway set to the router anyway. Have you tried using a VPN client on your local machine rather than relying on your router? It makes it a lot more difficult to troubleshoot if relying on the router.

 

[C.J]

I assume, 192.168.1.101 is your IP address on the remote network? How have you set this?

Yes that's the remote network IP for this user (me), setup in the user creation on the router.

Have you tried using a VPN client on your local machine rather than relying on your router? It makes it a lot more difficult to troubleshoot if relying on the router.

I have Server 2008 in the office, which we used to use for VPN, however for some reason this new router fails to send the traffic through (we've changed routers). Which is why I'm now using the router to sort the VPN, rather than port forwarding to the server.

EDIT - I still can't see the other PCs from home, however, while on the VPN I can log into the remote router, so it's definitely seeing the network (ie 192.168.1.1 = office router, 192.168.2.1 = home router) - both can be seen/logged into from home)

 

[C.J]

Ok, I've got it to work now (I've gone back to using the server to handle the VPN connections, rather than the router).

I can now see the other machines on the network using their IP. Is there an easy way to view the machines via their name?

 

[H182]

Have you set the DNS on the remote dial in (VPN) properties to point to the DNS server at the office?