A management module is implemented in a virtualization software of a virtualized computing device having one or more virtual machines and a virtual switch configured therein. The management module detects a mismatch between a maximum transmission unit (MTU) of the virtual switch and an MTU of a virtual network interface of a virtual machine. An error message may be immediately returned so that the MTU of the virtual network interface may be corrected in response thereto. Otherwise, an error flag indicating the MTU mismatch is set but the connection between the virtual switch and the virtual network interface is allowed to be established. The error flag may be used as a prompt to correct the MTU of the virtual network interface at a later time or to connect the virtual network interface to a different virtual switch.