Background

Some Comcast home modems are providing an IP space for the locally (home) connected devices that is in the same space as NPU's IP space. This causes an issue with users granted VPN access to campus, as their computer no longer can identify the correct network path to access remote resources – rather it no longer can differentiate what's remote traffic (like Colleague) from local traffic (like a local wireless printer).

To fix this issue, we need to change the LOCAL IP space on the Comcast modem to be a 192.168.0.x address, instead of the 10.0.0.x address.  

Instructions

1. While connected to the WIFI in the trouble location, verify that Comcast equipment is set to the 10.0.0.x space.

   1. Make sure that you are disconnected from VPN.

   2. Check the IP address of the machine:

      1. For Windows, open cmd and type "ipconfig -all". Look for a 10.0.0.x IP address assigned to the machine.

      2. For MAC, open System Preferences → Network. Looking at the connected connection, it will tell you the IP address.
         
         

2. Find the "router" or "gateway" address.

   1. For Windows, this will be the "Default Gateway" address in the above ipconfig result.

   2. For MAC, hit "Advanced" on the connected connection, choose the "TCP/IP" tab, and it will be listed as "router".
      
      

3. Open a web browser and enter the router/gateway address identified and login.

   1. You will need the login information to the router/gateway. Assuming this is rented equipment from Comcast/Xfinity.

   2. The default username: "admin" and password: "password" are often successful. It may also be printed on the device, or you may have to contact your ISP.

   3. It may prompt you to change the password when you login, and then ask you to login using the new password.
      
      

4. Verify that they don't have anything statically connected to the network.

   1. Navigate to Connected devices, and verify that all connected devices are "DHCP".

      1. If any are "STATIC" special attention will need to be made to those devices to change their IP address.

      2. If all are "DHCP", we're good to proceed.
         
         

5. Change the local IP space.

   1. Verify that other connections in the house are not occurring (like a student doing classes from home) - as this change will take a few minutes, during which all connections will be interrupted.

   2. Navigate to "Gateway" → "Connections" → "Local IP Network"

   3. Change the "Gateway Address" from “10.0.0.x” to “192.168.0.x” under the IPv4 section. You will not be able to change the last octet (the x).

   4. You'll see this also changes the DHCP Beginning and Ending address fields.

6. Save Settings

   1. Saving will disconnect all devices connected to the router.

   2. You will be disconnected for 3-5 minutes while the equipment reboots. Devices will obtain new IP addresses and re-establish internet connection.

   3. Select Save Settings when you are ready to start the process and commit the changes.
      
      

7. Test

   1. Check the IP address from Step 1. Verify that it is now a 192.168.0.x address.

   2. Connect to VPN and login to their on-campus resource.

   3. If other devices at this location (AppleTV, wireless printer, gaming systems, etc.) have issues connecting, a simple reboot of the device should resolve the issue.

   4. You may want to verify that other devices are picking up the new IP address.

Open

Open

Open

FAQ

Q: "Will this change my wireless SSID (network name) or password?

A: No. Those will stay the same.

Q: If I forget my password I just set, am I stuck?

A: Do your best to remember it, as we all don't want to deal with Comcast Support, however, they have access to your modem and can default the password for you if you forget it.

Q: My printer doesn't work anymore after this change, even though it's gotten the new address.

A: Depending on how your printer was setup before, your computer may be remembering its old address. Remove and re-add the printer.