A VPN can erase geographical barriers for a company, enable employees to work efficiently from home and allow a business to connect securely with its vendors and partners. A VPN is usually much cheaper to own and operate than private lines.

On the other hand, the use of a VPN can expose a company to potential security risks. While most VPNs in use are now fairly secure in and of themselves, a VPN can make it more difficult to secure the perimeter of a network properly. It is incumbent upon network administrators to apply the same security standards to computers connecting to the network via VPN as computers directly connected to the LAN.

Combining the use of two VPNs simultaneously can potentially expose one company's network to another's. In addition, using remote control software such as PC Anywhere, GoToMyPC or VNC in combination with a VPN can expose the company's network to the malware present on a remote computer that is not itself connection to the VPN.

Reliability, scalability and performance of VPNs

Because secure VPNs rely on encryption and some of the cryptographic functions used are computationally expensive, a heavily used VPN can load down its server. Administrators typically manage the server load by limiting the number of simultaneous connections to what the server can handle.