[Techtalk] RH7.2 Server Question
samanthablackmon at yahoo.com
Wed Apr 24 18:31:09 EST 2002
On Wednesday 24 April 2002 03:14 pm, a magikal owl from Kai MacTane delivered
> 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
*nods* It is set to allow both ssh and smtp connections as well. I will
double check because I have a bad habit of misremembering the ways that I
actually set things, but I do distinctly remember setting it to allow
conntections to those ports because I remember thinking how insecure but
doing it anyway.
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