Warning: Do
not repeat this step after your MTU has been set because the PING command will always report a value 28 bytes lower than the actual maximum packet (MTU) size due to IP and ICMP headers. Your MTU value will
never be lower than 576; 576 is the
minimum MTU any TCP/IP router
must support. If the MTU value the PING command returns is less than 576, your MTU was previously set. Also, DUN 1.3 and Windows 98 automatically set the MTU to 576 for connections slower than 128kbps (1500 for connections faster than 128kbps). An MTU of 576 is
not the best setting for online gaming if your ISP supports a larger size and could cause up to 2% of packet loss you may experience.
Therefore, if you change ISPs and/or your MTU has been previously set
or install DUN 1.3 or use Windows 98 and allow either to automatically determine and set your MTU (see the
Lean 'Network' Settings section), you will need to set the MTU (see Step 3, below) to an extremely large value (for example 2000) and reboot in order to receive an accurate MTU response from the PING command before you continue on to Step 3. If the PING command continues to respond with a value lower than 576 after resetting the MTU, your ISP only supports the minimum MTU setting of 576, set your MTU to 576 and proceed on to Step 4.