How to quickly determine MTU in LAN and Internet Environments

MTU (maximum transmission unit, MTU) refers to the maximum data size (in bytes) that can be passed on a layer of a communication protocol ).

For details, please go to the "MTU"

How to quickly determine the MTU of the current network environment:

 

Ping-F-l IP address to be spelled out in bytes

 

For example, Ping-F-l 1472 192.168.1.1

 

If the Ping is successful, try to increase the value of 1472. If the Ping is as follows:

C: \ Users \ Jimmy. Yang> Ping-F-l 1473 192.168.3.254

Pinging 192.168.3.254 with 1473 bytes of data:
Split the data packet but set DF.
Split the data packet but set DF.
Split the data packet but set DF.
Split the data packet but set DF.

Ping statistics for 192.168.3.254:
Packet: Sent = 4, received = 0, lost = 4 (100% lost ),

 

This indicates that the data needs to be split and the value is reduced. The value is pinged. My local computer and Internet test showed that the value is usually 1472 in the LAN environment, and 996 in the Internet environment.

 

Why are these two values? The TCP/IP header is 28 bytes, and the maximum packet length in the LAN environment is 1500, so 1472-28 is exactly 996, while 1024 + 28 = is exactly 1 K in the Internet environment