Scanning office IP when home network overlaps
3 posts · Closed
Hi
I am looking for advice. I am in a situation where a friend is trying to connect to his office via VPN. The connection is successful, but he cannot access his data folder. I believe the problem resides in the fact that his home router is leasing IPs in similar ranges as his office.
Example: his office gateway is 192.168.700.1/21 and his home router is 192.168.700.1/23
His data folder resides on a machine with IP 192.168.700.14/21, but there is some device in his house with IP 192.168.700.14/23. So every time he pings the .14, the one in his house answers, so he never gets to the data folder. If we scan on his machine with NS, the scanner shows the IP (.14) with its proper MAC address (home device) but with a correct DNS resolution (office machine name) because the VPN connection DNS points to the office. Those IPs that are not home-assigned appeared in NS with the MAC address of the VPN connection.
Is there any way to make NS find (scan) the office .14 IP?
It is not a problem with the Network Scanner app. It is how networks work in general.
You have an address space conflict between a local device with a certain IP address and a remote device with the same address. In such case, which address Windows connects to would depend on the routing table and route metrics (cost).
As a temporary solution, the user can add a new routing table entry to specify that .14 should be accessed via the VPN link rather than the local device. To do that, open an elevated command prompt and type:
route add x.x.x.14 <IP of VPN adapter>
This will add a specific route to x.x.x.14 via the VPN adapter. You can read more about this issue and alternative solutions in this discussion.
P.S. An octet in an IP address can range from 0 to 255. I.e. it cannot be "700" as in your example.
Thanks. Your advice helped me to resolve the issue.
Sorry for terrible example.