SSH (Secure SHell) is a protocol for running commands on a remote computer.
43
votes
6answers
10k views
Keep SSH Sessions running after disconnection
I sometimes have long running processes that I want to kick off before going home, so I create a SSH session to the server to start the process, but then I want to close my laptop and go home and ...
38
votes
9answers
21k views
SSH easily copy file to local system
If I'm logged in to a system via SSH, is there a way to copy a file back to my local system without firing up another terminal or screen session and doing scp or something similar or without doing SSH ...
34
votes
6answers
10k views
How can I disown a running process and associate it to a new screen shell?
I have a running program on a SSH shell. I want to pause it and be able to unpause its execution when I come back.
One way I thought of doing that was to transfer its ownership to a screen shell, ...
25
votes
2answers
2k views
How does SSH connection survive a network restart?
From a Linux SSH shell, type /etc/init.d/network restart to restart the network service.
I expect my SSH connection to die since the network service goes down. But it doesn't. Very cool. But how does ...
22
votes
1answer
3k views
Kill an unresponsive ssh session without closing the terminal
Is there a way to disconnect from an SSH session that has become unresponsive without killing the whole terminal? Specifically I'm using konsole, and the machine I'm working with sometimes hangs, but ...
19
votes
3answers
5k views
How can I break away from an SSH session that has crashed?
Many times I have an SSH session that doesn't respond anymore (for example, when I lose internet connection and then reconnect). Ctrl+C, Ctrl+D, Ctrl+Z and a zillion of key presses don't have any ...
18
votes
9answers
20k views
SSH tunneling error: “channel 1: open failed: administratively prohibited: open failed”
When I open this ssh tunnel:
ssh -nXNT -p 22 localhost -L 0.0.0.0:8984:remote:8983
I get this error when trying to access the HTTP server running on localhost:8984:
channel 1: open failed: ...
17
votes
5answers
3k views
Is it possible to run ssh-copy-id on port other than 22?
I have a server with SSH running on a non-standard port. Instead of 22, it runs on 8129. To log in, I use:
ssh -p 8129 hostname
Now, whenever I need to set up a key for password-less login, I have ...
17
votes
4answers
2k views
Is there a way to communicate with someone at their desktop?
My wife is sitting at her home desktop, alpha, which is running a recent version of Ubuntu. I am on a bus, using ConnectBot on my G1 phone, and can SSH into alpha from wherever I am.
For complicated ...
17
votes
4answers
12k views
What does the Broken pipe message mean in an SSH session?
Sometimes my SSH session disconnects with a Write failed: Broken pipe message. What does it mean? And how can I keep my session open?
I know about screen, but that's not the answer I'm looking for. I ...
17
votes
4answers
3k views
Can mouse wheel scrolling work in a /usr/bin/screen session?
Is there any way to use the mouse wheel to scroll through the output of a screen session?
I can use the keypad scroll through previous output in screen after pressing ctrl+a [. Is it possible to do ...
16
votes
4answers
6k views
How to speed up X over SSH on a slow network connection?
Are there any specific recommendations on speeding up X applications over ssh on a slow network connection? In this specific case, I am accessing a server located in west coast from a laptop in east ...
16
votes
5answers
9k views
How to speed my too-slow ssh login?
Running ssh user@hostname takes ~30s. Here's the scenario:
this is a VM on the local LAN
Windows and Mac machines get instant login
am using Debian and I could reproduce with an Ubuntu machine
...
16
votes
3answers
4k views
Restricting an SSH/SCP/SFTP user to a directory
Is there a simple way to restrict an SCP/SFTP user to a directory? All methods that I've come across require me to set a chroot jail up by copying binaries, but I don't think that should be necessary.
...
16
votes
3answers
4k views
Quoting in ssh $host $FOO and ssh $host “sudo su user -c $FOO” type constructs
I often end up issuing complex commands over ssh; these commands involve piping to awk or perl one-lines, and as a result contain single quotes and $'s. I have neither been able to figure out a hard ...
16
votes
2answers
13k views
What does the options `ServerAliveInterval` and `ClientAliveInterval` in sshd_config do, precisely?
I found this question, but I'm sorry I don't quite understand the settings on the two variables ServerAliveInterval and ClientAliveInterval mentioned in the accepted response. If my local server is ...
15
votes
8answers
21k views
Why am I still getting a password prompt with ssh with public key authentication?
I'm working from the URL I found here:
http://jaybyjayfresh.com/2009/02/04/logging-in-without-a-password-certificates-ssh/
My ssh client is Ubuntu 64 bit 11.10 desktop and my server is Centos 6.2 64 ...
15
votes
1answer
591 views
Is it safe to give out my SSH public key for work?
I currently work remotely for a number of organizations which need me to access their servers regularly for maintenance and upgrades. Is it safe for me to add my RSA public SSH key to the ...
15
votes
4answers
34k views
How to forward X over SSH from Ubuntu machine?
I have a machine running Ubuntu which I SSH to from my Fedora 14 machine. I want to forward X from the Ubuntu machine back to Fedora so I can run graphical programs remotely. Both machines are on a ...
15
votes
4answers
3k views
Can I find out which ssh key was used to access an account?
Is it possible to find out which ssh key was used to access an account? I have an account on a server that I let several (trusted!) people have access to via ssh. I'd find it useful to be able to ...
15
votes
3answers
2k views
scp: How to Enable Autocompletion for Remote Paths?
I remote copied a file to my laptop using:
scp someFile USER@192.168.178.32:/home/USER/put/it/some/where/oh/damn/you/here
I am too lazy for this! I want to be able to autocomplete the remote path ...
14
votes
2answers
1k views
SSH output isn't line buffered?
I'm running a script on a remote machine like this:
ssh $host "pip install -r /path/to/requirements.txt"
But the output isn't line buffered; instead of seeing one line returned at a time, all the ...
14
votes
2answers
4k views
How does reverse SSH tunneling work?
As I understand this, firewalls (assuming default settings) deny all incoming traffic that has no prior corresponding outgoing traffic.
Based on Reversing an ssh connection and SSH Tunneling Made ...
14
votes
1answer
6k views
ssh-add complains: Could not open a connection to your authentication agent
I've been trying to get ssh-add working on a RaspberryPi running Raspbian.
I can start ssh-agent, when I do it gives the following output into the terminal:
...
13
votes
2answers
470 views
Accidently created a file called -X, how can I delete it? [duplicate]
Possible Duplicate:
How do I delete a file whose name begins with “-” (hyphen a.k.a. dash or minus)?
Like an idiot, I ran this command:
tar -cf -X awstats-icon icon ...
13
votes
8answers
1k views
How can we limit the impact of ssh probes?
My webserver is constantly attacked by various IP addresses. They try five passwords and then change the IP address.
I have done various lockdowns like using ssh-keys and not permitting passwords, ...
13
votes
5answers
8k views
How can I run a script immediately after connecting via SSH?
I started to ask this question but answered it while I had it open. I'm going to post this question, follow it up with my solution and leave it open to other potential solutions.
<backstory>
...
12
votes
5answers
2k views
How can I tell what version of OS X I'm on from the command line?
I frequently find myself SSHing into various OS X machines, and it'd be useful if I could tell what version of OS X I was on when I'm doing that. uname -a doesn't quite work, since Darwin kernel ...
12
votes
3answers
790 views
Why change default ssh port?
I've noticed lot of admins change default ssh port. Is there any rational reason to do so?
12
votes
5answers
454 views
what's the purpose of ssh-agent?
I've read the official definition:
ssh-agent is a program to hold private keys used for public key authentication (RSA, DSA, ECDSA). The idea is that ssh-agent is started in the beginning of an ...
12
votes
3answers
3k views
SSH inside SSH fails with “stdin: is not a tty”
I'm trying to connect to machine one with ssh and then connect to another machine two with ssh, but I get this error.
ssh user@computerone.com 'ssh otheruser@computertwo.com'
stdin: is not a tty
...
12
votes
3answers
2k views
What's the difference between SFTP, SCP and FISH protocols?
I used to think SCP is a tool to copy files over SSH, and copying files over SSH is called SFTP, which is itself a synonym to FISH.
But now as I was looking for a Total Commander plugin to do this in ...
12
votes
2answers
425 views
(SSH) Is it dangerous to close terminal without “exit”?
This happened many times.
While the SSH active, I'm so tired and just close the terminal without exit
Is it dangerous to doing like that?
12
votes
3answers
3k views
Answer yes in a bash script
I'm trying to do a git clone trough a bash script, but the first time that I run the script and the server is not known yet the script fails. I have something like this:
yes | git clone ...
12
votes
4answers
5k views
SSH to decrypt encrypted LVM during headless server boot?
When I installed Ubuntu 10.04 and, now, 10.10, I was offered the option of enabling "encrypted LVM" for my hard drive.
After choosing that option, I am prompted for my password during boot to decrypt ...
12
votes
3answers
6k views
scp without replacing existing files in the destination
How do I copy an entire directory into a directory of the same name without replacing the content in the destination directory? (instead, I would like to add to the contents of the destination folder)
...
11
votes
4answers
704 views
What is SSH - the protocol and what is ssh - the utility?
What is SSH - the protocol?
What is ssh - the unix utility and how does it work?
How is SSH protocol related to SFTP?
What is sshd?
Does the command su use ssh or sshd?
11
votes
6answers
2k views
How do I copy all files and directories except certain ones over ssh?
Using the Linux command line, I use the scp command to copy up all the files and folders from a certain directory. However, I don't like to consume wasted bandwidth for copying up things I rarely ...
11
votes
2answers
3k views
How do I know if my ssh tunnel is created successfully?
I rely on the following script tunnel.sh written by others to keep a ssh tunnel alive:
#!/bin/bash
export SSH_HOST=tim@server
if [ ! -f /tmp/.tunnel ]
then
echo "Creat SSH tunnel"
ssh -f -D 9999 ...
11
votes
1answer
383 views
How to prevent shutdown when an SSH user is logged in?
I'm administrating a networked environment and I had an interesting situation arise yesterday. When a host is required to shutdown by a regular user, it refuses to do so if other users are logged in ...
10
votes
2answers
416 views
How to temporarily switch from ssh to my local shell?
I'm using cygwin. and use it with ssh to login into a ubuntu server. sometimes, I want to switch back to my cygwin and then quickly switch to ubuntu shell. How to do this?
10
votes
4answers
242 views
Does a `scp` transfer close when I close the shell?
I have scp transfer (from one remote server to another), that is quite big.
So maybe I want close the computer from which I executed this command, will this end the transfer? I have ssh access to ...
10
votes
3answers
445 views
ssh via multiple hosts
To get to my machine in my office, at the moment I am doing this:
me@home:~$ ssh unix.university.com
me@unix:~$ ssh unix.department.univeristy.com
me@unix.department:~$ ssh ...
10
votes
2answers
1k views
Using an already established SSH channel
I have an already established ssh connection between two machines.
Is there a way to send commands to the remote machine from a shell script that is run on the local machine, using the already open ...
10
votes
5answers
739 views
How to copy a file that is still being written over ssh?
Here is the situation:
I am uploading a large file from client A to a server using sftp.
I also need to download this file from the server to client B over ssh.
What I would like to do is start ...
10
votes
1answer
370 views
Understanding SSH tunnels
I have linux (Ubuntu) server which I have root access to through ssh (port 22) only. On that server there is a MySQL database listening on port 3306. Is it possible to use putty (on my machine) and ...
10
votes
3answers
810 views
How can I lock my own account from remote ssh login with password?
I don't want to disable remote login with password altogether, but I want to make it so that my account is only accessible with key pair authentication (there are other users who wants to use ...
10
votes
3answers
802 views
Can SSH passwords be sniffed out over Wi-Fi?
When you ssh, can the password you enter to connect, be intercepted if you're using untrusted public Wi-Fi (coffee shop, library, airport, etc).
10
votes
4answers
2k views
How can I solve this ssh-agent problem?
I'm using Linux Mint, and have not been able to get gnome-keyring to unlock automatically at login, it seems.
A symptom of my problem is as follows:
$ ssh-add
Identity added: /home/me/.ssh/id_rsa ...
10
votes
2answers
276 views
Groups differ from the local ones when logging in remotely
We store our users in LDAP, alongside some groups that have meaning across different systems (organizational roles including wheel). There are also groups local to workstations, e.g. audio or video ...
