| flyingfader |
Une idée comme une autre:
tu vas à cette adresse
http://www.dslreports.com/tweaks
tu fais le test puis tu suis le lien TWEAK FAQ ( http://www.dslreports.com/faq/tweaks )et tu lis tout ce qui concerne RWIN et MTU et le petit utlitaire DrTCP.
Exemple:
Finding the largest MTU, by EXPERIMENT
If your MTU is too low already, (maybe 576), the following method will not be able to detect whether you can switch to an optimal size..... So first follow "CHANGING MTU for PPPoE" to reset MTU to 1500, reboot, then come back to this!
The best value for MTU is that value just before your packets get fragmented. How do you find out that? By using Ping at an MSDOS command prompt.
Go to Start/ Programs/ MSDOS-PROMPT, and type....
ping -f -l 1472 www.dslreports.com
(That is a dash-ell not a dash-one. Also note the spaces in-between the sections) Press Enter. Then reduce 1472 by 10 until you no longer get the "packet needs to be fragmented" error message. Then increase by 1 until you are 1 less from getting "packet need to be fragmented" message again.
Add 28 more to this (since you specified ping packet size, not including IP/ICMP header of 28 bytes) And this is your MaxMTU.
Note:If you can ping through with the number at 1472, you are done! Stop right there. Add 28 and your MaxMTU is 1500.
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For PPPoE, your MaxMTU should be no more than 1492, to allow space for the 8 byte PPPoE "wrapper", but again,
experiment to find the optimal value.. For PPPoE, the stakes are high: if you get MTU wrong, you may not just be sub-optimal, things like UPLOADING, or web pages, may stall, or not work at all! [jfdsdjhfuetppo]--Message édité par FlyingFader le 23-04-2002 à 01:28:10--[/jfdsdjhfuetppo] |
