Client connection always succeeds for port 1720

  • Thread starter Thread starter Philippe Perrin
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Philippe Perrin

Hi

When I try to connect to ANY SERVER on port 1720 (netmeeting), with Windows
2000/XP or 2003, the connection is always successfull, whether the port is
accepting connections or not.
For example, if I run "telnet www.google.com 1720" the connection is
established, although netmeeting does not work on www.google.com. I can
connect from windows to any system on port 1720.

Why does the Windows socket API establishes connections to 1720 ports on any
sustems, even if 1720 is not open??

Thanks
Philippe
 
Philippe Perrin said:
Hi

When I try to connect to ANY SERVER on port 1720 (netmeeting), with Windows
2000/XP or 2003, the connection is always successfull, whether the port is
accepting connections or not.
For example, if I run "telnet www.google.com 1720" the connection is
established, although netmeeting does not work on www.google.com. I can
connect from windows to any system on port 1720.

Why does the Windows socket API establishes connections to 1720 ports on any
sustems, even if 1720 is not open??

Thanks
Philippe
Click to expand...

it doesn't. tried here to and from nt4, win2k, and winxp and none of them
accept nor incorrectly report connections to port 1720. you might want to
check your router, some routers will send you back to your own default
server if they can not resolve the external address properly.
 
Actually the two PCs used for this test (WinXP, Win2003) are connected
directly to the ISP, with no private routers in-between. The external
address has no resolution problem, because when running the same telnet
commands to the port 21, we are correctly connected to our FTP servers.

I'll check with my ISP, maybe they can explain that to us.

Meanwhile, if you guys have other ideas.... they'll be very welcome :)

Thanks
PhP
 
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