Accessing UCF’s Linux Servers
The primary method of accessing a server running the Linux operating system (primarily RedHat Linux here at UCF) is via SSH, or Secure SHell. This provides an encrypted, text-based command line interface to the server. This document discusses some requirements and suggested methods for accessing UCF’s Linux systems.
Establishing a Network Connection
First, access to UCF’s network is required. This can be done in one of the following ways:
· A desktop workstation on campus. Normally desktop systems are permanently connected to the UCF network, however sometimes the desktop’s network address (often referred to as its IP address) must be authorized to connect to a particular Linux server. Ask your instructor or supervisor if a particular workstation you wish to use is authorized. Some instructional Linux servers don’t require an authorized connection and you can use any workstation on campus.
· A laptop on UCF’s wireless network. Normally this type of network connection can only access Linux servers that don’t require using an authorized workstation, such as a public instructional server. Servers that require an authorized network connection cannot be accessed from a laptop or any other device on UCF’s wireless network.
· A VPN connection from off-campus. This requires running special software on your laptop or desktop computer that establishes an encrypted connection over the Internet to UCF’s network. UCF provides free VPN software for Windows, Apple MacOS, and Linux. You can download the software and access installation and configuration instructions at the following website:
When you access the website you will see the following:
Select which group (faculty or students) you are a member of and then enter your NID and password. If you are a staff member, use the faculty group.
Using SSH
Once you have access to UCF’s network, you then need to start an SSH program in order to login to the Linux server. There are a variety of SSH software programs available, some of which may already be installed on your computer. What program you need depends on your operating system:
· Windows: Our favorite program is putty, however you can use any SSH program designed for use on Windows. You can obtain a free copy of putty from the following website:
To use putty, first access the program on your computer (an example for Windows 10 is shown):
When Putty starts, you will see the following:
In the “Host Name (or IP address)” box, type in the address of the Linux server you wish to access. Ask your instructor or supervisor for the address. When you have typed in the address, click on the “Open” button. You will then see the following:
Type in your userid and password to login to the Linux server. Your userid and password can either be your NID and its password, or a special userid and password provided to you by your instructor or supervisor.
· Apple MacOS: Apple MacBooks and desktop computer come with an SSH program already build in. You can access it easily by bringing up search:
And then search on the program “terminal”:
Once you start the terminal program, you will see something similar to the following example:
At the prompt, type in the following command:
ssh userid@address
Where ‘userid’ is either your NID or a special userid provided to you by your instructor or supervisor, and ‘address’ is the address of the Linux server. Note that the userid and password are separated by the ‘at’ symbol. Ask your instructor or supervisor what address you should use.
Using Linux
Here are a few basic commands for getting around Linux:
· man – Get help on most any command on the system.
· ls – Simple directory listing.
· ls -a – Directory listing with more details.
· cd – Change directory.
· cp – Copy a file.
· mv – Move or rename a file.
· rm – Remove/delete a file.
· exit – Log off of the system and end your session.
A few more basics on using Linux:
· To start a program or application, you usually can just type its name at the command prompt. Sometimes you may need to type additional options on the command line following the program name. Check with your instructor or supervisor on how to use any assigned programs or applications. You can also use the ‘man’ command to get help on many applications.
· Sometimes you may be granted access to run a special ‘privileged’ command (sometimes referred to as a ‘root’ command). In order to run these special commands, use the ‘sudo’ command:
sudo command options
Where ‘command’ is the command to run and ‘options’ are any needed options. If you are prompted for a password, use the password you logged into the system with.
· If you need to move files between your computer and the Linux server, there are many programs available to do this. One of our favorite programs is ‘winscp’ which runs on Windows. You can obtain a free copy of winscp from the following website:
Once you start winscp, you will see the following:
Under ‘Host name:’ type in the address of the Linux server you are trying to access, then below it enter the userid and password of your account on that server. Once you are logged in, you will see the following:
Your computer and its file are on the left, and the Linux server is on the right. Simply drag and drop files between the two sides to transfer them between your computer and the Linux server.