Not able to connect to any server using Telnet

Question

I am new to Telnet. I have been trying to connect to different servers. I type the following command in my Linux terminal:

telnet 74.125.236.160

and then after sometime I get the message:

unable to connect to remote host: connection timed out

What might I be doing wrong?

Answer 1

You'll be able to telnet onto port 80 of almost any website, including google. Your problem is that you did not include the port.

telnet google.com 80
Trying 216.58.220.238...
Connected to google.com.
Escape character is '^]'.

Just for fun, let's see what other ports google has open:

nmap google.com

Starting Nmap 7.01 ( https://nmap.org ) at 2017-06-13 17:11 KST
Nmap scan report for google.com (216.58.220.238)
Host is up (0.040s latency).
Other addresses for google.com (not scanned): 2404:6800:4004:806::200e
Not shown: 998 filtered ports
PORT    STATE SERVICE
80/tcp  open  http
443/tcp open  https

Just the two services. http and https. If you check your browser, you'll notice you're always redirected from http to https when you go to google. We can see that port 443 is an open port from the information we received from nmap. Let's confirm:

telnet google.com 443
Trying 216.58.220.238...
Connected to google.com.
Escape character is '^]'.

And that's all there is to it.

Answer 2

Try

ping 74.125.236.160

If ping responds(assuming no firewall blocks it)

telnet 74.125.236.160 <port>

i.e.

telnet 743.125.236.160 80

Answer 3

Somehow I don't think Google (the owner of that range of IP addresses) has allowed remote telnet access for newbie users!

Try something a little more vulnerable and not so well firewalled, like another device on your local LAN such as a network connected printer or your router.

Attempting a telnet connection to outside devices can sometimes be interpreted as launching an attack on them, and appropriate security responses may result.