SSH

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CS remote environment

The SSH protocol makes a given Unix machine's command line available over the network. Computer Science offers SSH access on two interactive login servers.

  • powerpuff.cs.brynmawr.edu - Linux
  • gl.cs.brynmawr.edu - Solaris

These servers can be accessed both on and off-campus. However, they will not be reachable from the BrynMawrGuest wireless network on campus due to blocks placed on that network. To connect to the CS login servers from a personal device on campus, use the eduroam or BrynMawrCollege networks.

Host key mismatch error

When the operating system on an SSH server is reinstalled (usually at least once a year), its host key changes, which will result in an error when clients that have stored the old host key try to connect.

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@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @                                         
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IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!                                               
Someone could be eavesdropping on you right now (man-in-the-middle attack)!                         
It is also possible that a host key has just been changed.                                          
The fingerprint for the RSA key sent by the remote host is                                          
6c:bf:9b:6e:68:d7:2d:44:da:d7:6e:9a:0d:a2:13:95.
Please contact your system administrator.                                                           
Add correct host key in /home/taro/.ssh/known_hosts to get rid of this                           
message.                                                                                            
Offending RSA key in /home/taro/.ssh/known_hosts:4
RSA host key for gl.cs.brynmawr.edu has changed and you have requested
strict checking.                                                                                    
Host key verification failed.

If this happens, delete the line in ~/.ssh/known_hosts referred to in the error message (it will begin with the hostname of the machine you are trying to connect to) and accept the new host key when reconnecting.

SSH clients

An SSH client is needed to connect to one of these servers. Unix-like operating systems like Mac OS X and most Linux distributions come with one built in.

Mac OS X

The Mac OS X terminal emulator is located at /Applications/Utilities/Terminal.app. To open the Terminal from the Desktop:

Linux (Fedora)

To open applications in the Fedora GNOME desktop:

Windows

Finding Putty in the Start Menu on a CS Windows system

Windows does not contain a native Unix command line environment, so Putty, a third party application, is used for SSH. Putty can be launched from the Start Menu search box.