Open the Command PromptClick on the Start button and enter 'cmd' into the Search field, and hit Enter.
Enter the Ping Command:Type ping hostname or ping IP address. (Note: an IP address is a specific address of your network given by ISP).
Example: ping www.google.com or ping 192.168.0.1.
Ping test to find proper MTU sizeTo find the correct MTU for your configuration. You will simply send out a ping request and progressively lower your packet size until the packet no longer needs to be fragmented. To check the MTU value, we need to first test for the maximum MTU (Maximum Transfer Unit) size (unfragmented). It is like pinging an IP address, but be careful, every router has a default MTU size value at 1500 byte. You need to find the correct one for your network. This will help you to find the correct value. This will be applicable for Netgear, D-Link, Linksys & other routers.
Different networks have different values provided by their ISP. For broadband connections, you don't need to decrease value '1400' but still, you need to check. Before we start, you need to open cmd prompt as shown above.
To open the command prompt as administrator, you will need to click on the Start button, type 'cmd' in the search field, then right click on cmd, and then select 'Run as administrator'.
You need to type this command in the command prompt to check if your MTU size is correct.
'ping www.yahoo.com -f -l 1500'
Note: The last four numbers are the MTU test packet size and 1500 is the default value.
If you get fragmented, decrease the packet size by 10. Enter "ping yahoo.com –f –l 1490", and press Enter. Keep decreasing, until you get the correct value. My network defragmented on 1500 value, but after trying further, I got the correct one at 1240.
After you get a correct value, you need to add 28 extra to that value. The reason for this is because, (20 bytes are for the IP header and 8 bytes are for the ICMP Echo Request header).
To save this value on LAN:You can save it on the router in 'WAN' page or by typing this command.
"netsh interface ipv4 set subinterface "Local Area Connection" mtu=1240 store=persistent"
To save this value on a Wireless LAN:You need to type this in cmd:
"netsh interface ipv4 set subinterface "Wireless Network Connection" mtu=1240 store=persistent"
Simply hit Enter and the MTU value will be set. Restart your PC for the change to take place. When I tried this out for myself, I got the correct value. I hope I have helped you to get your correct value. If you decide to try it and encounter any issues, feel free to ask questions. I'll try to help you as much as possible.
This was the best and most helpful information I have come across on how to do the ping test. Thanks!