This article designed to show you how to setup configure VPN access in order to enable remote access to your home computers from the Internet. This article is designed for CCNA students, network engineers, and anyone looking to the VPN Passthrough feature. This article falls under the CCNA syllabus’s objective “Explain and select the appropriate administrative tasks required for a WLAN”. VPN technology allows you to link to your home network from the Internet securely. Once the VPN connection is established, a tunnel is created between your urgent computer and the other device on your home network. Data exchanged through the VPN tunnel is encrypted. Thus, your data can traverse the internet securely.

Some of the VPN protocols are IPSec, PPTP, and L2TP. In order to establish VPN connections to your internal network, you should configure the router to allow the VPN protocols you are actually using to pass through its firewall.

Now, let us expect that you want to access your network PCs from the internet, and you have a static public IP address configured on your Linksys router (if you do not have a static public IP address, then you can configure the Dynamic DNS feature and access your internal PC using the router’s domain name). To do this, follow these steps:

1. Enable a VPN server on your network.

2. Configure the router to redirect incoming VPN traffic to your VPN server. To accomplish this, open Port(s) associated with the protocol(s) used to establish VPN connections (IPSec: UDP Port 500; L2TP: UDP Port 1701; PPTP: TCP Port 1723).

3. Enable the protocol(s) used to establish VPN connections to pass through the router’s firewall. To do this, follow these steps:

Step 1: Open your favorite web browser application, and enter the IP address 192.168.1.1 in the address field. Then press Enter.

Step 2: In the authentication dialog box, enter the administrator’s username and password. The default values are admin/admin for the username/password. However, on some Linksys router platforms, the default value for the username is the blank and for the password is admin.

Step 3: Open the Security tab.

Step 4: Click VPN PassThrough.

Step 5: Click Enable for the protocol(s) used to establish VPN connections.

Step 6: Click Save Settings.