Pptpclnt.exe and Pptpsrv.exe are tools that work in unison to
verify that the required protocol and port for Point-to-Point
Tunneling Protocol (PPTP) are being routed from a PPTP client to a
PPTP server or vice versa.
In order for a PPTP client to access a remote PPTP server, all
routers in between the two hosts MUST allow traffic to pass through
TCP
port 1723 (PPTP) and must support protocol type 47. Protocol type
47 is the GRE (Generic Routing Encapsulation) protocol.
PPTP Ping runs on Windows XP Professional,
Windows 2000, Windows NT, and Windows 98, but not on
Windows 95.
Notes
You must run PPTP Ping from the command window.
This tool is not meant to test the functionality of a PPTP
server or a PPTP client. It is meant to assure that the path
between the two hosts goes through TCP port 1723 and uses the GRE
protocol (type 47).
Point-to-Point-Tunneling Protocol (PPTP) is a networking
technology that supports multiprotocol virtual private networks
(VPNs), enabling remote users to access corporate networks securely
across the Microsoft Windows operating systems and other
Point-to-Point Protocol (PPP)-enabled systems to dial into a local
Internet service provider to connect securely to their corporate
network through the Internet.