1. Adding a user on a local computer:
As you can see in this screenshot, a user with a username, "jburce" has been added on the local computer.
In this part of the exercise, I have learned how to add a user by typing in a command in the terminal which is:
$sudo adduser jburce
jburce, being the username I assigned for my newly created user. It is a new experience for me, since I was accustomed to adding user accounts through the control panel (in Windows) but in here, I have added a user using only a command.
2. Logging in to a remote computer via SSH using the username-password combination:
In this part, I have logged in to a remote computer or server which has an IP address of 172.16.7.88 and was named by our instructor as "PAHO" using the user account I created at first which was named, "jburce". The username and password that I entered in PAHO was also given to us by our instructor beforehand. At first, I was having problems with creating my user and logging in since the previous class might have modified some changes in the local computer I was using, but somehow in the end I have managed to successfully create a user and even logged in it. Now that I have logged in to PAHO with my account details, (i.e. username,password) I can now configure it, for a passwordless login.
3. Configuring the local computer for a passwordless login:
In this part of the exercise, we must first type in the command:
$ssh-keygen -t rsa
$<enter>
$<enter>
$<enter>
When we typed in this command, it has generated a public/private rsa key pair. The public key or public id that was generated is used to authorize the username I had. In order that for my next login, entering my password will no longer be required. With the use of this public key cryptography, as per in the handouts have said, you can already login to a remote computer (or server) without using a password. As how to this happen, I want to know but I think it's still not covered for our topic today. But somehow, I want to really know how they do the public key cryptography part.
Using the following command:
$ssh-copy-id jdeb2@172.16.7.88
The ssh command will throw the username and password to PAHO [remote computer/server] and save the identity[username and password] for authentication/passwordless login.
In this image you can see what happened when the command was typed:
As you can see here, I have logged in using the username jdeb2 without it asking for may password. Meaning, reconfiguring my local computer for a passwordless login was SUCCESSFUL.
4. Broadcasting message to other users connected to the remote computer using wall (write to all):
As you can see here, I have broadcast a message with other users with my username jdeb2 and other users have also broadcast their message in the wall. It struck to me, the idea of Facebook's wall and how it may be created. It's like having a Facebook social networking site in a local network.
5. Sending a message to a particular user only using write:
In this part, we have learned how to send a personal message [pm] to a specific user in the network only. The other user's username is rclha and he began writing a message to me by saying, "halloowwwee! xD" and then i replied with, "pag kelangan magwwrite ka" he replied with "direply ka, pang scre n?" and he also replied with "pag hindi ikaw yung unang nagwrite"
All others are just broadcast messages. In this part I have learned, and the other user learned how to create a simulation of chat using the write command and other commands such as echo and wall (with specific username addressed to). It gave me an idea how most sites with chat capabilities work through the network.
As per the question raised in the handout, I think that when you log in to a different work station, it wouldn't still be passwordless because the configurations are set only for the local computer you have used while making the user account to be passwordless.
This whole experience in the exercise, enlightened me to various things that you can do in a network and how to set configurations for like, passwordless login. I do hope by the next exercises, we could still learn other configurations we could do around the network. Like how to properly create a network of local computers. or how to connect to a server, things like that I want to learn.
