ET181:Connecting to the Linux Computer Server "condor"

Topics:
Access to the Linux Computer Server "condor"
Logging into and out of the system
Basic UNIX/Linux commands

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Access to the Linux Computer Server "condor"

The ET181 course uses a Linux computer server (named condor) which can be accessed remotely through the University ethernet system. You will be given an account only on this computer. There are two distinct modes of access, depending on what you would like to do. The ssh (secure shell) access mode allows a remote PC to behave as a "dumb terminal" of the Linux server, whereas the sftp (secure file transfer protocol) allows the transfer of files between a PC and condor. You cannot mix modes of access and will have to decide a priori which mode you wish to use. All the PCs in the Stocker computer labs can be used to access the condor computer. In the ET181 course you will use both modes of access, as required.

Finally it happened. During 2009 we had to block telnet (teletype network) access to the condor computer server, since it was determined by OIT (Office of Information Technology) to be a security risk. This is unfortunate, since telnet allowed access directly from the web. Fortunately there is a freely available implementation of a ssh client for Windows operating systems named PuTTY, which has been developed and maintained by Simon Tatham and can be downloaded directly in a portable binary format as an executable file named putty.exe. This file can be conveniently stored on and executed directly from a flash-drive. Thus for those of us who have personal laptops, we will still be able to conveniently access condor through the ssh option using putty in Perk's Coffee House, Donkey Coffee, or wherever there is wireless internet access (I find it much more relaxing to develop my C++ programs while sipping on a medium chai-tea-latte.). When you invoke putty be sure that the ssh option is highlighted and assuming that your condor login id is smithj, fill in the host address as follows: smithj@condor.ent.ohiou.edu.
For the lucky few of us who have Macs, the process is a lot simpler since all current Macs use the UNIX operating system which automatically includes the ssh option. Open the web and fill in the url as follows:
ssh://smithj@condor.ent.ohiou.edu

Quick Quiz: What does url stand for and what are the two main components of a url? (Answer)

Concerning sftp (secure file transfer protocol) which we will not require before lab 7, again Simon Tatham has come to our rescue, and has developed a portable binary format file which can be downloaded directly from his website as an executable file named psftp.exe (putty secure file transfer protocol). We will have more information on using this protocol in lab 7. Again the Macs have an advantage. There is an excellent sftp option available for the Macs named Fetch which can be freely downloaded directly from the Ohio University software and downloads resource on the web.

Accessing condor from the PCs in the Stocker computer labs
One first needs to complete the PC login process using your oak ID user name and password. Follow the instructions on the PC to complete the PC logon, and then continue as follows:

Login to condor

Logout of condor and the PC

Basic UNIX/Linux commands

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