On Mon, 29 Jul 2002, rob.edkins(a)axon.co.nz wrote:
There's a somewhat simpler reg hack on Windoze.
Set HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\EnablePMTUBHDetect to 1
This enables automatic 'Black Hole' router detection and triggers automatic MTU scaling.
BTW, the 'Don't Fragment' Bit is on by default with Windows.
http://www.microsoft.com/windows2000/techinfo/reskit/en/cnet/cnbc_imp_yvjd.h... has more details. The ResKit says the following: Description Determines whether TCP tries to detect black hole routers during the Path MTU (maximum transmission unit) discovery process. Enabling black hole detection increases the maximum number of times TCP retransmits a given segment. If the value of this entry is 1, TCP recognizes when it has transmitted the same segment several times without receiving an acknowledgement. It reduces the maximum segment size (MSS) to 536 bytes, and it sets the Don't-Fragment bit. If, as a result, receipt of the segment is acknowledged, TCP continues this practice in all subsequent transmissions on the connection. -- Juha Saarinen - To unsubscribe from nznog, send email to majordomo(a)list.waikato.ac.nz where the body of your message reads: unsubscribe nznog