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Computer Science
FAQ - Spring 2014
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NOTE: The student machine is:

wormulon.cs.uidaho.edu

other CS machines do not accept ssh sessions. Also, make sure that are connecting using your CS user id (e.g., abcd1234). It appears many failures are related to these two issues.

repeated failed password/login attempts

Security programs are running on wormulon to prevent brute-force ssh hack attempts. These programs work by watching various log files for multiple login failures for certain users, such as root or guest, or attempts from non-friendly (a subjective term, to be sure) network addresses. When an attack is detected, the host IP address or network may be blocked.

Generally, the model is adaptive, allowing network addresses historically used by CS students to remain open even with multiple login failures but, as with any automated program, problems may occur and your IP address may be blocked. The result of this type of block is that wormulon will simply "disappear" and you will not be able to make any connection to it after repeated login failures.

First, don't panic. The blocking programs are somewhat lenient with regards to the local ISPs. Wait a full ten (10) minutes and try to connect again. If wormulon is responding, you will be able to log in with your correct user name and password. If wormulon does not respond after ten minutes, browse to whatismyip.com to determine your IP address. Please send your IP address to the and let us know that wormulon is not responding to ssh.

wormulon not responding to ssh

If wormulon does not respond to an ssh connection attempt and you know that your internet connection is working and you have not had repeated login failures (see above), make sure that you are using the full name and domain in your client: wormulon.cs.uidaho.edu.

If using the full name fails, try using the IP address of wormulon, instead: 129.101.178.124.

If you are still unable to connect, browse to whatismyip.com to determine your IP address. Please send your IP address to the and let us know that wormulon is not responding to ssh.

This is a relatively rare occurrence although it did happen once in Fall 2010. NOTE: wormulon does not respond to pings from off-campus, thus, ssh is the only way to test the connection.

permission denied errors with a correct password

If you using ssh to connect to wormulon and seeing permission denied errors after entering your password, it may be that your ssh client is sending your local user name as your login name. This is more likely to happen if you are trying to connect from a Mac or linux machine from the command line. The easiest way to fix this is to provide your login name for wormulon on the command line:

ssh user1234@wormulon.cs.uidaho.edu

connection is immediately closed after login

The most likely cause of the connection closing immediately after login, is because of too many connections. wormulon allows only four (4) simultaneous connections for each user and subsequent connections will be immediately dropped if the limit is reached. This can cause problems if the connections were accidentally dropped (see Dropped Connections, below) because it may take up to fifteen minutes for wormulon to close these disconnected sessions and allow logins again.

It is important to properly log off of wormulon with the logout or exit command before closing your ssh client. Terminating the ssh client without logging off may not end the session and may cause a session to remain active for a short time and contribute to the limit problem. If you are having problems send mail to the and we can free the connections. Users on intermittent connections should use caution when taking advantage of multiple ssh sessions.

The connection to wormulon is getting dropped

The most common problem students experience with wormulon is dropped or disconnected active sessions. wormulon will automatically logout sessions that are connected but inactive, but only after at least two (2) hours, so the problem is most likely that the local service provider has a very short inactivity timeout. It does appear to affect students living in apartment complexes more often and could be related to traffic within the complex.

If you are experiencing frequent dropped connections, the recommended ssh client PuTTy can be configured to send null packets every x seconds to keep the session alive. For PuTTy, from the Configuration window, select Connection. Set the "Seconds between keepalives" to a number greater than zero. A good start would be 300 (five minutes) but if disconnects are still occurring, a lower value will be required.

Login failures

Usually, login failures are related to incorrect user IDs or passwords or not being in one of the CS access lists. User IDs and passwords are case-sensitive and may contain special characters. Access to wormulon and the computers in the CSAC requires your VandalWeb credentials and you must also be in an access group or list for CS. If you have forgotten your VandalWeb password, we cannot reset it for you. You must take a photo ID and go to the ITS Help Desk in the Commons. If you know that your VandalWeb credentials are good, write the CS Help Desk and we can make sure that you are in the access list.


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