Windows 2x/XP MTU settings

[Jaime Garcia]

We have been installing Cisco VPN client on our laptop
computer and have recently noticed that when installing,
the MTU settings are set back to 'default'.
We would like our max settings to be set to 1300.

Does anybody know how to set the default for all
network/ras adapters found to be 1300 and not
the 'default' (1500)?

 

[jpww]

"MTU

Key: Tcpip\Parameters\Interfaces\interface



Value Type: REG_DWORD-number



Valid Range: 88-the MTU of the underlying network



Default: 0xFFFFFFFF



Description: This parameter overrides the default Maximum Transmission Unit
(MTU) for a network interface. The MTU is the maximum packet size, in bytes,
that the transport can transmit over the underlying network. The size
includes the transport header. An IP datagram can span multiple packets.
Values larger than the default for the underlying network cause the
transport to use the network default MTU. Values smaller than 88 cause the
transport to use an MTU of 88.



Note Windows 2000 TCP/IP uses PMTU detection by default and queries the NIC
driver to find out what local MTU is supported. Altering the MTU parameter
is generally not necessary and may result in reduced performance. See the
PMTU detection discussion in the TCP section of this document for more
details. "


The rest of this document can be found here:

http://www.microsoft.com/technet/treeview/default.asp?url=/technet/itsolutio
ns/network/deploy/depovg/tcpip2k.asp