Ports?

Excallent, thanks again guys.

and just one other thing...can Hackers connect to my comp via Telnet?? I am guessing the answer is yes...but since I don't know a whole lot about Telnet I thought it is better to ask.

Hades, it depends on what you mean by Telnet. Telnet is both a service, and program that comes with Windows and *nix distributions. As for the service, Windows NT-XP Pro include a Telnet service, and even if you only have Windows 95-XP Home, there is still a possibility that you could be running one. You can check for this by opening a command line and typing "telnet 127.0.0.1 23" (without the quotes of course). This runs the Telnet program, connecting to the IP-address 127.0.0.1 on port 23. 127.0.0.1 is the IP-address that you can use to connect to your own computer, and 23 is designated port for Telnet. If the connection goes through, the Telnet service is running, and unless you specifically want this service to run, disable it. With ZoneAlarm, no one would likely be able to connect to a Telnet service running on your computer, but as I said before, a trojan could set up it's own service on port 23. (Just because a port is usually used for one service, does not restrict another service from using it.)

As for the Telnet program, it can be used to connect to a computer on any port, so if you have configured ZoneAlarm to keep a specific port open, a hacker could use the Telnet program to connect to your computer on that port. For an example, try going to the command prompt again, and typing "telnet google.com 80". 80 is the port for HTTP (or WWW) connections, and I am sure you know what google.com is. Once connected (by the way, for this you want to have local echoing turned on in the preferences for Windows Telnet) type "GET / HTTP/1.1{Enter key}{Enter key}". Do not type {Enter Key}{Enter key}, I mean for you to press the Enter key twice(could someone tell me how I could write that better?); the Enter key is essential. This is a basic HTTP command (maybe I'll write a tutorial on HTTP sometime). The google.com server should send you some HTML code which a browser would translate into a pretty-looking web page (hey! I could write a tutorial on HTML too!). Hopefully, this has enlightened (and not confused ;))both you and JagFire19 a little more about how ports work.

By the way, I am glad that both of you have asked your questions. I takes bravery to ask questions, especially when you are new to something, and I know that your questions and the answers to your questions are useful to a lot of people who are not quite as brave. Oh! Also, thanks THEJRC, for posting your info on port 11. I will have to read that RFC.

Hey, thanks alot!!! That has really helped me!!! I just have one more query...I am running xp, and when I run talnet, after it connects or soemthing the program just closes itself! Whats going on there?? or am I doing something wrong.
Once again, thanks!

Not sure. They might have changed the way the Telnet program works since Me. If I try to connect to a server with Telnet, and I cannot get a connection, an error message pops up, but Telnet keeps running. Similarly, if the server closes the connection (because of timing-out or whatever), a different error pops up, but Telnet does not close. Oh, and I forgot on the last post, you have to press Enter twice. Sorry about that.

Yes! Thank you T2K2...It wasn't clear until you explained it. I now understand that a HUB just connects a network of computers and that ports are not the physical devices on the back of it.

Hades: How are you going about running the telnet client? Do you just go to a Run prompt and type telnet xx.xx.xx.xx or are you going to a Run prompt and typing cmd to get a command prompt, then typing telnet xx.xx.xx.xx? Just curious since this happens when you try to run certain progs from the run prompt instead of in the command terminal window.

Jagfire: I'm glad I could help. ;)

Now that you know all about the ports, here is a list of common ports and their most likley services : http://www.hackerwhacker.com/portslist.html

I go to run>Telnet then type: o <server (eg: www.hotmail.com)> <Port # eg 23)

I also tried the way susgested to me: run> telnet google.com 80

I think it's because the server's you're trying to connect to are not listening for a telnet connection, or you cannot use telnet to connect to the specific ports you are trying to connect to. For example, I used your first method to connect to my company's smtp server to try and send an email via telnet (which you can do, but I have not really put any time into it). The syntax was: start, run, telnet, o, smtp.xxxxx.com 25 (since smtp server's listen on port 25 by default for smtp service. If I were to just do smtp.xxxxx.com, it would try to connect that server on the default telnet port - port 23. However, what if the telnet daemon/server was not running? That would mean that the connection would timeout/fail. I tried a server that I knew was not running the telnet service, and I got the problem you described. Maybe you are trying to connect to something that will not accept a telnet client connection. I hope this helps you at least a little.


t2k2