MTU not found!

[Guest]

Hi. I am running MS windows XP pro sp2, AMD Athlon 2.8gh with 512 DDR.
Recently when I ran a system check, it returned a message saying that "MTU
NOT FOUND!" Since this occured, I have been unable to download at a
reasonable speed (I am 750kb cable) or download for long before any
downloading prog shuts down! Can I manually replace the missing MTU in
registry? Please help!

 

[R. McCarty]

A tool Dr. TCP can set/re-establish a MTU value.

MTU (Maximum Transmission Unit) or Packet Size is by default set
to 1500 (Max). However, depending on your ISP and how you are
connected (ADSL, Cable) the normal/optimal value is less.

A way to test is using Ping - to determine the value at which the packet
needs to be fragmented (Broken up to send).
You open a Command Prompt (Start, Run (Type) Command [Press Enter]
Click focus in the command prompt box & type

Ping -f -l 1464 DSLReports.com
The expected Ping response should be 0% lost

Repeat the above command incrementing the numerical value until you
receive a Ping message "Packet needs to be fragmented but DF Set".
Once this is received, move back one value & add 28 to it. That is
your optimal MTU value

1464 + 28 = 1492

 

[Rick \Nutcase\ Rogers]

Hi,

See if this helps:

HOW TO: Change the Default Maximum Transmission Unit (MTU) Size Settings for
PPP Connections or for VPN Connections
http://support.microsoft.com/?kbid=826159

--
Best of Luck,

Rick Rogers, aka "Nutcase" - Microsoft MVP

Associate Expert - WindowsXP Expert Zone

Windows help - www.rickrogers.org