A user must know the issues and circumstances in which the MTU ( maximum transmission unit) of a network should be changed. If a user is facing a sudden disconnection or slow data transfer issue on his network, he can change the MTU of a Dlink router using the dlinkrouter.local window. An incorrect MTU can affect the performance of your router that’s why a user is recommended to apply the default MTU in the provided field. The default MTU value of a Dlink router is 1499.