Is Telnet available under MacOSX/Snow Leopard?

I'm needing to know the answer to this, as I'm planning to possibly switch from using a Windows machine to a Mac, and the existence of Telnet on the machine is crucial to my being able to communicate with my Internet router to periodically change an ADSL parameter on the line between my router and the exchange - the target SNR. My particular router (router-modem) has a chipset that allows this. The change is crucial to the stability of my line connection. I'm currently able to effect this change, which I need to do on a fairly regular basis, on my Windows machine by telnetting into the router at the commandline level or by using a Windows-only utility that's in effect a GUI-based version of telnetting. It remains questionable, however, as to whether it will be possible to do the same sort of operation on a Mac.

From googling, the impression I get is that Telnet is no longer available on Macs; apparently, it was withdrawn by Apple some time ago, due to it being a bit of a security risk. However, one or two individuals have suggested that it is still available on Macs, even in its non-secure original format. It was my impression that Telnet had now been completely replaced by something called 'ssh'.

Either way, if telnetting of some sort is still available on the Mac, how would I get into the 'debug' scenario where I can log into my router and ask the router, through a commandline format, to execute a change to the ADSL line parameters?

Doing this through Windows, I first of all have to enable debug via the web interface by:

http://<router LAN IP address>/setup.cgi?todo=debug

I then telnet into the router using its LAN IP address and, when logged in (username as well as password), I type:

adslctl configure --snr N, where N is an integer.

I know next to nothing about the Mac's Unix-based OS but I presume that the debug command will be something entirely different. But maybe, once into the router, the 'adslctl configure --snr N' command to the router will be the same.

To come out of Telnet, I type exit.

Yes, you can use "terminal", which is built in.

I would suggest getting iTerm - it is free but much more powerful.

Matt

Uno,

I'm not sure what you're saying, Uno. Is Telnet actually still there, on the Mac, or has it really been replaced by ssh? If Telnet's still there, do you know which 'debug' command(s) I'll need to use to get in? I understand how I'll get to Terminal - you find it by clicking on Applications, then Utilities, then Terminal.

What does iTerm do? I don't need anything especially powerful, as all I want to be able to do is to communicate with the router for essentially just that one 'configure' command.

Err, i'm a little confused.

You don't have to do anything to get it to work. Just open terminal/iterm and type telnet like this screen shot shows.

http://scrn.in/m/eced06370703be33cd828afad2f1b71b.png

I've never had to enable it, or ever heard that it has been disabled.

Matt

I think the confusion has come about because of the Netgear debug enable command. That sets a flag on the router that means it accepts telnet connections. If you enter the telnet command without enabling debug the router will reject the (telnet) attempt.

The underlying MAC OS is Unix. Telnet comes as standard.

Telnet is a TCP/IP network protocol that is independent of OS. It can be implemented under any OS; even if the manufacturer doesn't provide it, I'm someone else will.

Yes Telnet is there.

Just think of Terminal in OS X as you would the Command Prompt in Windows.

Telnet is available.

Obviously SSH is better, but not really needed when working over the LAN.

This is all good news to read. But just a few queries:

1) What are the default username and password? Indeed, is there both a username and a password to use?

2) John2007 has supported me in a particular detail: What will be the equivalent debug enable command, to enable the router to accept the telnet connection? Exactly the same as the one used in Windows, namely "http://<router LAN IP address>/setup.cgi?todo=debug"? And would that debug command also be inputted via the Mac's browser?

3) To telnet into the router, is a port no. also required?

4) How do you end a telnet session on the Mac? Do you just type "quit" followed by Enter?

BTW, I trust you're all referring to the very latest incarnations of MacOSX, as I have a book on the Tiger edition and, in that, it states that Telnet is not available?

Edited by deleted (Sat 24-Jul-10 20:36:57)

"1) What are the default username and password? Indeed, is there both a username and a password to use?"

I suggest you type man telnet at the Terminal prompt. That will tell you how the telnet command can be used. As far as I know there is nothing special about the OS X implementation of telnet, so anything you are used to doing in Windows is likely to work in OS X.

"2 )would that debug command also be inputted via the Mac's browser?" Of course. It's just sending an HTTP request.

"3) To telnet into the router, is a port no. also required?" No. The Netgear routers use the default port number for Telnet protocol, and that is what OS X assumes if you don't use the port option.

"4) How do you end a telnet session on the Mac? Do you just type "quit" followed by Enter?" Probably. Whatever you use in Windows ...

Whatever book on Tiger you are using should be thrown away or treated with suspicion. Telnet has been available from day 1 in OS X. It's just UNIX with a pretty user interface!

Edited by deleted (Sat 24-Jul-10 20:55:49)