Cluster Access
Cluster Access
We recommend MobaXterm for general ssh access. Mobaxterm is an enhanced terminal client for Windows with X11 server, ssh client, and variety of network tools.
Other flavor of Xservers like Cygwin, Xming, are all OK.
For MAC users, please install XQuartz. XQuartz is an open-source effort to develop a version of the X.Org X Window System that runs on OS X.
For linux users, please directly use ssh command to log in.
For users who desire Graphical Desktop Interface, please use VNC Viewer or NoMachine Client.
Case 1: You got an "ssh_exchange_identification: read: Connection reset by peer" response when trying to ssh the server
Cause: This means that your IP has been blocked by the server. From any IP if it attempted to log in as root or attempted to log in with wrong username/password combination, the access will be blocked. Attempt of root log in will be blocked 25 days. Too many wrong username/password combinations will be blocked 24 hours.
Solution: You may either wait 24 hours for an automatic release or email the administrator for blockage removal.
Case 2: You got a warning like this:
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
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
SHA256:XXX.
Please contact your system administrator.
Add correct host key in /home/lzhou/.ssh/known_hosts to get rid of this message.
Offending RSA key in /home/username/.ssh/known_hosts:linenumber
RSA host key for nodemm has changed and you have requested strict checking.
Host key verification failed.
Cause: This usually happens when the Operating System of the node was upgraded or the hardware of a node is replaced. It rarely means that somebody is hijacking your network route to the server.
Solution: Edit the file ~/.ssh/known_hosts on your local computer or X client, remove the offending line, and retry log in. Then you will see the following prompt:
The authenticity of host 'nodexx (x.x.x.x)' can't be established.
ECDSA key fingerprint is SHA256:xxxx.
ECDSA key fingerprint is MD5:yyyy.
Are you sure you want to continue connecting (yes/no)?
Please answer "yes" and the new host key will be saved and you should be able to log in again.
If this happens too frequently, like coming back in a few days, it will mean that there is really man-in-the-middle attack. Please contact the site administrator or your ISP to investigate.