MTU Discovery ( RFC1191 ). Determines whether TCP uses a fixed, default maximum transmission unit (
MTU) or attempts to find the actual
MTU. Under
Windows 9x, if the value of this entry is 0, TCP uses an
MTU of 576 bytes for all connections to computers outside of the local subnet. If the value of this entry is 1, TCP attempts to discover the
MTU (largest
packet size) over the path to a remote host.
