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Shell account tutorial

432 bytes added, 22:39, 23 February 2018
Troubleshooting
This Provides a summary of basic SSH usage on acidburn, with notes for ECE 2524 students as well. In the future, these will be separated into two pages.
One advantage of a shell account is that it allows one to leave an IRC client constantly connected, eliminate join/quit spam, and
log missed messages to check later. In order to accomplish this, the IRC client must be run inside either [[tmux]] or [[screen]] so that
it will not be killed when you disconnect from SSH.
== CVL SSH accounts ==
The ECE2524 VM (128.173.88.125) can be accessed via SSH for CVL users, and has tmux, mosh, and weechat installed. The
[[gp:CAD and Visualization Laboratory|CVL]] does ''not'' have any IRC clients installed, but is also useful for general computing (e.g. [[MATLAB]]). == Acidburn ==
One advantage of Acidburn (acidburn.vtluug.org), the VTLUUG shell server, has a shell account is that it allows one to leave an few more IRC client constantly connectedclients installed, eliminate joinas well as other software and <s>full</quit spam, andlog missed messages to check laters> partial IPv6 support. In order to accomplish thisBecause of new restrictions on SSH access (all of port 22 is blocked for off-campus users, the IRC client must although we ''shouldn't'' be run inside either [[tmux]] or [[screen]] so thatit will not blocked), Acidburn can be killed when you disconnect from SSHaccessed at port 2222.
== Acidburn ==Acidburn (We strongly recommend setting permissions of '''all''' files on your acidburn.vtluug.org)home directory to 600, the VTLUUG shell server, has except for a few more IRC clients installed, as well as other software <s>and full IPv6 support<public_html/s>directory.
== Basic Usage ==
#* ''Use this whenever you are inside a tmux window and wish to return to a shell''
# To, reattach to the first tmux seesion, just use <code>tmux attach</code>
#* <code>user@ece2524:~$ tmux attach-d</code>.
#* ''On subsequent logins, this should be the only command you need to execute to return to IRC''
'''If you have been given a temporary password please reset it by running
<code>user@acidburn:~$ passwd</code>'''
==Other SSH Suggestions==
* Use [https://wiki.archlinux.org/index.php/SSH_keys SSH Keys]
* Write up your own [[tmux|tmux.conf]]
* Use X-forwarding on servers that support it: <code> $ ssh -X user@client.server.tld </code>
* Check out the [http://www.dayid.org/os/notes/tm.html tmux and screen cheat sheet] for a quick reference of some of the other tmux commands. An additional command that might be useful is <code>tmux list-sessions</code>.
*[http://mosh.mit.edu Mosh] is another helpful tool you may want to use for high-latency or mobile (e.g. wifi) connections. You also may want to look into zsh, an alternative to bash with more features.
*You also may want to setup an [http://nerderati.com/2011/03/simplify-your-life-with-an-ssh-config-file/ SSH config file] for host aliases and Kerberos authentication.
 
==Random Bash tips==
* Ctrl-D is the universal "end-of-file" command, and can be used to logout of shells
* Ctrl-C is the universal interrupt command, and can be used to kill running terminal jobs and clear your currently-typed command (rather than holding down backspace).
* Ctrl-Z can be used to pause processes, then fg or bg can be used to restart it in the foreground or background, respectively
==Troubleshooting==
* You (or someone using your IP address) have had too many failed login attempts, and fail2ban or a similar utility has banned you for a period of time, typically a week or so.
** This is easy to identify because ssh fails ''before'' you are prompted for a password.
** If this happened on a CVL machine, try connecting to a different node like <code>$ ssh pid@cvl10.ece.vt.edu</code> == See Also == * [[WeeChat]]* [[Irssi]]
==External Links==
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