Noob port question

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I was messing around with some port scanners and network sniffers,
testing a machine of mine at home for vulnerabilities.  I noticed
several ports were open, but using telnet to connect to them, all I
get is a black screen.  I was wondering what to do next...after I have
found an open port.  How can I connect to it?  Is there programs which
will help with this or built in windows commands I am not aware of?

Re: Noob port question (Billy) wrote:

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What you can do once you connect to a port is totally dependent on the
protocol that the server on that port is implementing.  For instance,
port 25 is normally for mail, so you can type SMTP protocol commands
like "EHLO", "MAIL FROM", and "RCPT TO" to it.

Some protocols make use of binary data rather than textual commands, so
there's typically not much you can do from an interactive telnet to the

To get the details of any particular protocol, read the specification,
which is usually in an RFC.  You can get RFCs from

Barry Margolin,
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***

Re: Noob port question

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For the record, here are the port/protocol combinations that are likely:

21/FTP (i.e., USER, PASS, unlikely to be successful from telnet due to
complexity of DATA channel.)
23/Telnet (i.e., command line commands)
25/SMTP (EHLO, etc.)
80/HTTP (GET /index.htm, etc.)
110/POP3 (AUTHINFO USER, etc.)
443/HTTPS (unlikely to be successful from telnet)

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