Configuring the MTU Value of an Interface

Background Information

The network layer generally wants to limit the maximum length of each packet sent. Any time the network layer receives an IP packet to send, it determines which local interface to send the data to and queries that interface to obtain its Maximum Transmission Unit (MTU). The network layer compares the MTU value with the length of the IP packet to be sent. If the length of the IP packet is greater than the MTU value, then the IP packet needs to be fragmented, and the length of the fragmented packet is less than or equal to the MTU.

The size of MTU determines the maximum number of bytes that the sender can send a message at one time. Correctly configuring the MTU value is a prerequisite to ensure normal and efficient communication between devices.

 - If the MTU is configured too small and the message size is large, it may result in too much message fragmentation, and the message may be discarded by the QoS queue, affecting normal data transmission.

 - If the MTU is configured too large, it may exceed the maximum value that can be tolerated by the receiving end, or it may exceed the maximum value that can be tolerated by one of the devices passing through on the sending path, which may also result in fragmentation or even discarding of the message, aggravate the burden of network transmission, and affect the normal transmission of data.

Procedure

1. Enter system view.

system-view

2. Enter interface view.

interface { interface-name | interface-type interface-number }| interface-type interface-number }

3. Configure the interface to switch from Layer 2 mode to Layer 3 mode.

undo portswitch

Only the S6730-H-V2 and S5732-H-V2 series support switching the interface from Layer 2 mode to Layer 3 mode via the undo portswitch command. Please choose by yourself whether you want to perform this step according to the current interface mode.

4. configure the MTU value of the interface.

mtu mtu

By default, the MTU is 1500 bytes. When you need to ensure that large messages in the network are not lost, you need to configure this step to set the size of message slicing and force slicing for large messages.

Check the configuration result

Execute the command display interface { interface-name | interface-type interface-number } | interface-type interface-number } to view the current running status information of the interface.

Huawei S6700 Series Switches

For Huawei product list and quote, please contact us at www.hi-network.com  (Email: [email protected])