# Introduction

Testing SSH access to the class environment

## Goals

- Log into your virtual servers with SSH
- Get familiar with the Ubuntu command line environment

## Notes

- Commands preceded with “$” imply that you should execute the command as a general user - not as root.
- Commands preceded with “#” imply that you should be working as root.
- Commands with more specific command lines (e.g. “rtrX>” or “mysql>”) imply that you are executing commands on remote equipment, or within another program.

## Overview

Each lab group has four environments set up to use. For instance, Group 1 is setup as follows:

    ns1.grp1.dns       (authoritative server)
    ns2.grp1.dns       (authoritative server)
    soa.grp1.dns       (hidden master)
    resolv.grp1.dns    (validator)

Group 2 uses “grp2” instead of “grp1”, etc.

The credentials (username and password) for each will be given to you by your instructors.

## Check that you can log in using ssh

The precise instructions for this depend on what ssh client you’re using. If you’re using something like OpenSSH on a command-line, you will probably do something like this to log in to the host ns1.grp1.dns using a username “jabley”:

      ssh jabley@ns1.grp1.dns

Check that you can log in to all four environments, using the user and password provided in class.

## Check that you can become root

We recommend using `sudo` when you need root privileges to do something. You can run individual commands with sudo, like

    sudo vi named.conf

or you can use sudo to create an interactive shell, e.g. so that you don’t have to remember to prefix every one of a set of commands with “sudo”:

    $ sudo -i
    #

Remember that root has the power to break things. Try not to break things.

## Take a look around

These environments are all built using Ubuntu 18.04. This is your chance to look around and ask questions about anything that looks strange.