telnet use? - Technology Forum - Home Theater, Computer, Televisions, Personal Electronics and more!

heatwave · 08-10-2006, 08:40 AM

I am refering to question of the Real World Questions.69. The answer is telnet. How can you use telnet to troubleshoot an http server?

blackhawk · 08-10-2006, 08:40 AM

by telneting to the web server on port 80 and issueing a GET command

heatwave · 08-10-2006, 08:40 AM

I tried to telnet into (the IP addresses not those names) from my computer (Windows XP Pro). Both times the connection was refused. I have tried telnet a few other times. I have never got a connection. Am I doing something wrong? How could I use telnet for troubleshooting if I can not get a connection?

blackhawk · 08-10-2006, 08:41 AM

type this at a command prompt

telnet yahoo.com 80
GET

after telneting to the server you get a blank screen just type GET
and hit enter a couple times it will display the server info and the web page in HTML text.

there are other commands such as CNTRL+] localecho that will allow you to see what you are typing.

heatwave · 08-10-2006, 08:41 AM

That works but when I type GET and then push enter thrice, the HTML scrolls up the screen very quickly and the connection is lost.

vega55 · 08-10-2006, 08:41 AM

Telnetting to any server and expecting anything other than a slap round the head from the admins is pushing it

Every time you telnet somewhere your address will be logged in an intrusion detection system (as long as one is running - and if you tried microsoft, you'd best believe one was running!) - systems are set up not just to detect port 23, but the telnet itself (on any port).
Many systems are set up to prevent anything by HTTP and possibly FTP over port 80 - anything else will quite rightly set alarm bells ringing.

Juniper -What you're talking about is an email bounce - something which spammers try to do, and any admin who works with email servers tries hard to block.

Email clients which 'forward' do so by simply sending via their normal smtp server, with a modified header. The email will still contain the originator address and your address, so it is considered a normal email.

blackhawk · 08-10-2006, 08:41 AM

make your buffer bigger or use logging. there are many things you can do with telnet to alot of ports, like telnet to port 25 on a mail server and send e-mail from it hehe! I have given you how to see a web page using telnet (now you know the server is up ,it works from routers also) just google and you will learn more commands and how to just pull server info like web server type can also send e-mail from open proxies (this is different then open-relay servers).

heatwave · 08-10-2006, 08:42 AM

When I telnet to the smtp server on one domain and try to send mail to any other domain I am told that the server doesn't permit forwarding. How does a mail client like OE or T-Bird do it?

vega55 · 08-10-2006, 08:42 AM

No, you are fine. Intrusion detectors on an SMTP server is probably not common. At least it is not from what I have seen. The more common approach is to simply require authentication. Which you cannot do using simple Telnet. You should be allowed to send mail from your ISP mail server using Telnet. You are in their network.

In order to send mail via telnet from other servers you need to find an open-relay or a proxy. In one of the classes I taught, an extra credit assignment was sending me an email using telnet, with a from: of CIS 270extra Credit. : )

Deddard, a bounce is a mail message that is sent to a server and the server rejects it for some reason. If you use telnet to a mail server you are allowed to send from or you use a relay, then you can send mail just fine with telnet. There is nothing wrong with doing it at all. You are doing manually what mail applications do for you automatically, nothing more.

It is a must have tool in your arsenal if your going to do diagnostics on mail clients.

heatwave · 08-10-2006, 08:42 AM

I didn't know that there was anything wrong with what I am doing. I mostly use my ISPs SMTP server (on port 25) to do this. I even called them about it once and was told that it was fine. They even took the time to make sure the commands that I was entering were correct. Are you saying that it is wrong to do? If so, I can just direct my questions about it to my ISP instead of here. Maybe Canada is more lenient about this than your country is. We are known for our lax laws.