telnet on local LAN question
fedora-list at cosiso.nl
Thu Aug 18 05:42:12 UTC 2011
>> An additional thing to check is if you are listening on port 23 (or 25).
>> Try "netstat -tnlp" and search ":23" (or ":25"). You will find the
>> name of the process listening. Check if it is listening on 0:0:0.0 or
>> just on 127.0.0.1. The 127.0.0.1 would be wrong, and should be fixed
>> in the configuration of the mail program.
> I have an entry for :25 ... 127.0.0.1:25. No entry for :23.
You just pinpointed why you can not telnet (port 23) or reach port 25.
The mailserver is only listening on localhost (127.0.0.1) and can't be
reached from other machines. And there is no telnet-daemon running, so
nothing will answer on that port either. (Also, as said in my previous
post: your firewall still does not allow port 25 connections.)
> Given that I am using telnet and not mail as it seems like a simplier
> problem to learn how to get commands/ports to work on my LAN (mail seems
> to have multiple ports and telnet is a single one ... and a very simple
> test to run), what do I need to do if 127.0.0.1 is wrong for telnet
> 23/25 or telnet without a specified port (which seems to be 23, right?)
Mail can be used on port 25 nicely, you just have to configure it to
listen on all interfaces. (Not sure what line is needed from the top
of my head.)
If you want to try it on telnet then you need a telnet-server
installed and running.
But why would you do that? If you can ssh/ping to the machines, you
have demonstrated they can reach each other finely and there is no
need for any telnet server, as that won't tell you anything you didn't
already know. You want to mail, so get your mailserver running on all
interfaces and open your firewall for port 25. Or, during tests drop
it altogether, until you know you can mail.
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