[Techtalk] RH7.2 Server Question

[Kai MacTane]

At 4/24/02 01:01 PM , Samantha wrote:

>--- Kai MacTane <kmactane at GothPunk.com> wrote:
> >
> > Do you have some kind of firewalling set up?
>
>Yes, but it is set to allow telnet.

The firewall distinguishes "telnet" by what port it's destined for. This 
means it will only allow connections to port 23. To get it to allow 
connections to ports 22 and 25, you'll need to set your firewall rules to 
allow connections to smtp and ssh. (I'm not sure if your firewalling 
software's UI does this by port number or by service name, so either "ssh" 
and "smtp", or 22 and 25.)

Basically, neither your firewall nor any other part of your server can tell 
what particular client program is being used on the other end of the 
connection; a telnet connection to port 25 looks just like a "real" SMTP 
connection, except that it proceeds at human typing speed instead of 
super-fast computer speed. Or, to look at it another way, a program 
actually connects to an SMTP server by forming a telnet connection to it.

                                                 --Kai MacTane
----------------------------------------------------------------------
"Why can't I live a life for me?
  Why should I take the abuse that's served?
  Why can't they see they're just like me?
  I'm not the one that's so absurd!"
                                                 --Ministry,
                                                  "Every Day is
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