User Manual

Setting the MTU size in Keenetic routers is possible via the web or command-line interfaces.

In the web interface, this setting is available on the Ethernet Cable Connections to Internet page in the IPv4 Settings section and the ISP Authentication (PPPoE / PPTP / L2TP) section if you are using a connection via the respective protocol.

In the IPv4 Settings section, in the MTU size field, you can specify the desired value between 64 and 1500. For a wired IPoE connection, the recommended MTU size is 1500.

In the section ISP authentication (PPPoE / PPTP / L2TP) click Show advanced settings. In the MTU size field, you can specify the desired value in the range from 64 to 1500. Ask your ISP for the recommended MTU value.

Also, you can use the command-line interface (CLI) of the router to set the MTU size. You should execute the following command to do it:

interface <interface_name> ip mtu <MTU_size>

For example, if you need to set the MTU = 1400 in the ISP interface (wired WAN interface to access the Internet), run the following command:

interface ISP ip mtu 1400

To save the settings to the non-volatile memory of the Keenetic device, be sure to execute the command:

system configuration save

You can see the interface names of your Keenetic by running the command:

show interface

then press the Space bar and the Tab button.

After changing the size of the MTU, you can execute the command to display information about the specified interface:

show interface <interface_name>

The command output will contain the current MTU value. For example, run the command for the ISP interface:

show interface ISP