MTU stands for Maximum Transmission Unit and is a set amount (in bytes) defining the maximum size a packet can be in data transmission, most notably Internet traffic. This is an important aspect of VyprVPN because there are a few scenarios in which mismatched or incorrect MTU settings on your network and in the app could cause trouble, such as websites failing to load. In most cases you should not have to adjust the MTU setting, unless otherwise advised to by our support team for troubleshooting purposes.
You can change this setting to meet your needs if it is required in the Advanced tab of the VyprVPN app.
You can also use the Optimize MTU button in the Advanced tab to have VyprVPN test your network and find the best possible MTU setting for your OpenVPN and Chameleon connections. The app does this by creating a temporary tunnel with which to send data packets back and forth at varying MTU sizes. Once a reliable packet size has been found, it will set the MTU number accordingly.