We’re often asked what the best MTU and MRU settings from customers, in order to optimise internet connections.

So let’s get started!

1.) Go to Start, and type ‘CMD’ in the search field. (in Windows/XP/Vista).

2.) At the command prompt, type in ping www.google.com -f -l 1492 and hit enter.

3.) You will notice that the above results indicate that the packet needs to be fragmented.

4.) You now need to lower the packet size, until the packets ‘do not’ fragment. (try 1450, 1440, 1430, 1420, 1400, etc)!

5.) Begin increasing the packet size in small increments until you find the largest size that “does not” fragment.

6.) Add 28 to that number (IP / ICMP headers) to get the optimal MTU setting. If the largest packet size from ping tests is 1450, add 28 to 1450 to get a total of 1478 which is the optimal MTU setting.

7.) Change the MTU settings, using the instructions here: Google

All the best!

Tags: mtu settings, pppoa, pppoe

This entry was posted on Wednesday, February 2nd, 2011 at 12:11 pm and is filed under ADSL Modems. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.