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Logging On to i4 Using SSH

The i4.nyu.edu machine, which provides shell access to the main NYU Web server, only supports secure shell (SSH) connections (not Telnet). In a SSH session, the information being sent back and forth (such as your password) is encrypted, so that if a mischief-maker intercepts your interactive login session, the data will be unreadable.

Connecting to i4.nyu.edu

For Mac OSX:

Open the Terminal application. At the prompt type:

ssh your_NetID@i4.nyu.edu

where your_NetID above is your NYU NetID. Click return to enter the information.

For Windows:

Open the PuTTY application. For Host Name (or IP address), type:

your_NetID@i4.nyu.edu

where your_NetID above is your NYU Net ID. Make sure that the Port is set to 22. Click the Open button.

For Linux/UNIX:

Open a terminal. At the prompt type:

ssh your_NetID@i4.nyu.edu

where your_NetID above is your NYU Net ID. Click return to enter the information.

Verifying Your Connection

The first time you connect to i4.nyu.edu, you will be asked to verify the identity of the server by acknowledging the fingerprint of the server's key. Answering "yes" will save the server's fingerprint into a local known_hosts/cache file. If this fingerprint ever changes, ssh will prompt you with an error message regarding a possible "man-in-the-middle" attack.

Please see the following screenshots for examples of this verification message on each platform: Terminal (Mac OSX) screenshot | PuTTY (Windows) screenshot

Entering Your Password

Once you've agreed to accept the server's key, you will receive the prompt:

Password:

Enter your NetID password (the same password you use for NYUHome) and hit return. Note, you will not see your password displayed on the screen.

Agreeing to the Responsibility Statement

Once you've correctly entered your password, you will see the "Responsibilities of All New York University Computer and Network Users" statement. Read through the statement (hit the space bar to continue through the document) and at the end, enter "Yes or yes" if you agree ("Y" or "y" will not be accepted).

Next Steps

You should now be at the i4 system prompt. If you will not be using the i4 command line interface, you may now logout of the system. Type logout and hit the return key to exit the system.


What software should I use?

Mac OSX users may make a secure shell connection using the Terminal application found within the Utilities folder inside the Applications folder.


Windows users may download secure shell software by logging into NYUHome, click on the "Ask ITS" link in the "Help, FAQs, Contact ITS" channel, then click the "Browse All" link. Or, you may visit the ITS Software Page directly. ITS provides PuTTY for Windows.


Problems?

Mac OSX users who have previously logged into i4 may receive a "WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!" error message when trying to log in using Terminal. This is because the IP address of i4 has changed. Therefore, if you receive this message, do the following:


Open a new Terminal window and type:

rm ~/.ssh/known_hosts

Then, type the following:

ssh your_NetID@i4.nyu.edu

where NetID above is your NetID. You should be able to login successfully. You can then type "exit" or "logout" to close the Terminal window.


If this doesn't work, type the following:

ssh your_NetID@devwww.nyu.edu

where NetID above is your NetID. You should be able to login successfully. You can then type "exit" or "logout" to close the Terminal window.