Find the answer to your Linux question:
Results 1 to 2 of 2
Hi I have a problem regarding Telnet when used as debugging tool Considering that you connect to a mail server on port 25 using the following command telnet mail.mailer.com 25 ...
Enjoy an ad free experience by logging in. Not a member yet? Register.
  1. #1
    Just Joined!
    Join Date
    Nov 2007
    Posts
    8

    Telnet


    Hi

    I have a problem regarding Telnet when used as debugging tool

    Considering that you connect to a mail server on port 25 using the following command

    telnet mail.mailer.com 25

    The mailer will reply and expect you to return smtp commands. Now my problem is the following. How thus the initial handshaking take place. Reasoning it out I understand that the mail server has to be able to do the telnet handshaking and establish aconnection before actually being able to accept smtp messages.

    So is the mailer able to understand both smtp commands and telnet commands the latter in order to set up the connection

    Thanks
    Aaron

  2. #2
    Linux Enthusiast
    Join Date
    Apr 2004
    Location
    UK
    Posts
    678
    The telnet handshaking is essentially just setting up a tcp connection. After that it simply passes characters around as it gets them.

    I have been told that there are telnet commands which I expect would upset the smtp server, but I have never encountered them myself.

    Telnet is very simple, the heavy lifting of logins and whatnot are handled by processes on the server.

    Does that help?

    Chris...
    To be good, you must first be bad. "Newbie" is a rank, not a slight.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •