SSH (Secure SHell) is a protocol for running commands on a remote computer.

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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, ...
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3answers
4k views

scp between two servers not in the same network

There are two server that I can access with 2 different VPN connections. I have managed to have both VPN working on the same time on my machine (a bit of routing rules). I want to do a scp <...
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4answers
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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?
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5answers
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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 X-...
13
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2answers
30k views

How to ssh to a server using another server? [duplicate]

Possible Duplicate: ssh via multiple hosts For connecting to server B I have to first ssh to server A. What's the command line to access server B?
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5answers
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How to make putty to not break my session after some time?

Each time putty is breaking session after some time if I am doing nothing. There is no any time parameter on putty so how can I stay my putty ssh session always Alive ?
13
votes
3answers
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SCP from one server to another without password prompt

What is the best way of doing scp from one box to the other without prompting for password? There are two servers: Server A (10.152.2.10): /home/oracle/export/files.txt Server B (10.152.2.11): /...
13
votes
3answers
24k views

ssh remote server on some port other than 22 without password

I am usually connecting to the remote server with ssh user@server.com -p 11000 and then giving the password each time for user. How should I avoid entering the password each time I connect ...
13
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3answers
12k 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 git@github....
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2answers
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SSH key-based authentication: known_hosts vs authorized_keys

I read about setting up ssh keys in Linux and have some questions. Correct me if I'm wrong… Let's say host tr-lgto wants to connect to host tr-mdm using ssh. If we want to be sure that it's the real ...
13
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3answers
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How can I make a user able to log in with ssh keys but not with a password?

I would like to create a user and have no password. As in you cant log in with a password. I want to add keys to its authorized_keys by using root. This is for my automated backup system.
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6answers
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SSH automatic remote back ups

I have two machines, A and B. Machine A can ssh into B. A has a lot of free space. B's data is in a sort of risky situation. How do I back up all of B's data to A automatically. It does not have to ...
13
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2answers
12k views

How do I force a user to change a password at the first time login using ssh?

I'm trying to force a newly created user to change a password at the first time login using ssh. For security reasons I want to give him a secure password until he logs in for the first time. I did ...
13
votes
4answers
6k views

How can I set default settings for htop?

Occasionally, I need to check resources on several machines throughout our data-centers for consolidation recommendations and the like. I prefer htop, mostly because of the interactive feel and the ...
13
votes
2answers
7k views

Tail log file on multiple machines over ssh

I'm trying to tail a log file on multiple remote machines and forward the output to my local workstation. I want connections to close when pressing Ctrl-C. At the moment I have the following function ...
13
votes
3answers
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Why does my X11 forwarding attempt fail with “connect /tmp/.X11-unix/X0: No such file or directory”?

On my local machine, I run: ssh -X me@remotemachine.com (For completeness, I have also tested all of the following using -Y with identical results). As expected, this accesses remotemachine.com ...
13
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2answers
39k views

Server does not accept public key for ssh login without password [duplicate]

Possible Duplicate: Why am I still getting a password prompt with ssh with public key authentication? I have ssh access to two sever. One old one and one new one. For the old one I use the ...
13
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3answers
2k views

Adding a user who can only execute scripts remotely

I would like to create a user who can only do one thing: via ssh specify a script ( and commandline arguments to the script ) that resides in one particular folder ( for the purposes of this question ...
13
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3answers
4k 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).
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4answers
970 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 ...
12
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4answers
10k views

Run a diff between local and remote files

I'm connected on a host via ssh and I'd like to compare (let's say with diff) a certain config file against its counterpart on an another host, also accessible via ssh, without having to manually ...
12
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2answers
7k views

How can I make ssh ignore .ssh/config?

I have the following in my ~/.ssh/config. HOST 10.2.192.* USER foo PreferredAuthentications publickey IdentityFile ~/.ssh/foo/id_rsa The above configuration lets me connect ...
12
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4answers
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Given keys in ~/.ssh/authorized_keys format, can you determine key strength easily?

~/.ssh/authorized_keys[2] contains the list of public keys. Unfortunately, each public key does not specify the key strength ( number of bits ). Is there a utility that can process this file line by ...
12
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3answers
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How to bring back SSH session that was started with the -f option (run in background)

I'm pretty lost on this. From the man page: -f Requests ssh to go to background just before command execution. After starting SSH with the -f option, I have a working tunnel. But after I ...
12
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8answers
10k views

How to rsync files between two remotes?

I would like to transfer files between two remote hosts using on local shell, but it seems rsync doesn't support synchronisation if two remotes are specified as follow: $ rsync -vuar host1:/var/www ...
12
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6answers
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How to effectively use screen and SSH?

I'd like to configure SSH and screen such that a login will always reattach to a screen session. Ideally, that session would not quit but detach when I press C-d. How can this be achieved? And what ...
12
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5answers
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Can a linux user change their password without knowing the current password?

I'm setting up a few ubuntu boxes, and using opscode's chef as a configuration tool. It would be fairly easy to install public keys for each user on each of these servers, and disable password ...
12
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4answers
48k views

How to ssh to remote server using a private key?

I have two servers. Both servers are in CentOS 5.6. I want to SSH from Server 1 to Server 2 using a private key I have (OpenSSH SSH-2 Private Key). I don't know how to do it over unix. But what I did ...
12
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4answers
29k views

How to copy with SCP between two servers using key auth?

I can log in via SSH using key authentication to SERVER1 and SERVER2. However, I can't copy files between the two servers. Why? How can I copy between them? (the data that I have to copy is bigger ...
12
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4answers
3k views

Stopping output from a program run in SSH session NOW

Problem I execute command that outputs LOTS of information through SSH. For example, I foolishly add debug information inside a loop that executes million times, or just run cat /dev/urandom for ...
12
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4answers
3k views

Advice for managing SSH keys

What is the best practice you have found for managing lots of SSH keypairs? I use SSH to connect to several systems, both at home and at work. I currently have a fairly small, manageable collection ...
12
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2answers
39k views

How to add a ssh user who only has permissions to access specific folder?

How to add an ssh user who only has permissions to access specific folder? useradd -d /var/www/xyz.com.tr/musteri -s /bin/bash -g sshd musteri I created a user called musteri. I set its home ...
12
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5answers
11k views

ssh prompts for password despite ssh-copy-id

I've been using public key authentication on a remote server for some time now for remote shell use as well as for sshfs mounts. After forcing a umount of my sshfs directory, I noticed that ssh began ...
12
votes
1answer
831 views

How to execute an arbitrary simple command over ssh without knowing the login shell of the remote user?

ssh has an annoying feature in that when you run: ssh user@host cmd and "here's" "one arg" Instead of running that cmd with its arguments on host, it concatenates that cmd and arguments with spaces ...
12
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3answers
6k views

Kill process spawned by ssh when ssh dies

This is a question that has been addressed several times, not only here, but also in other sites of the stack exchange network (e.g. http://stackoverflow.com/questions/331642/how-to-make-ssh-to-kill-...
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2answers
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How to pipe a remote file to stdout over scp or sftp?

Using ssh, it is easy to print the contents of a file using ssh host 'cat file.txt' When ssh is disabled, and only SFTP is enabled, running the previous command gives the following error: This ...
12
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2answers
26k views

How to edit authorized_keys?

What is the best method for editing the /root/.ssh/authorized_keys file? I mean if I need to append a new key to my authorized_keys file, than what are the best methods to do that?
12
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1answer
15k views

Foreign characters won't display in SSH

I'm having some problems with using ssh and a remote server (which I do not have admin access to) - Specifically, there are a couple of folders on there with Korean and Cyrillic text. When I display ...
12
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1answer
5k views

How to use ssh-agent with multiple (valid) keys and yet choose which one to use?

Let's say there are two keys A and B, both of which are valid for user@host public key authentication. Since authorized_keys is configured for different behaviour depending on the key, ~/.ssh/config ...
12
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3answers
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sudo over ssh: no tty present and no askpass program specified

I keep getting this error and have tried several ways discussed online to fix this and none are working for me. I have setup SSH keys so when I run 'ssh newton@host.com' it automatically logs me in, I ...
12
votes
1answer
8k views

Remote desktop over SSH reverse tunnel to replace TeamViewer

I want to open a remote desktop session from my laptop to desktop over my SSH (reverse) tunnel. That should be simple (or at least doable), right? Until now I've been using Team Viewer to log in to ...
11
votes
4answers
65k views

rsync without prompt for password

I need to execute rsync, without it prompting me for password. I've seen in rsync manpage that it doesn't allow specifying the password as command line argument. But I noticed that it allows ...
11
votes
7answers
32k views

How do I work with GUI tools over a remote server?

I have an Ubuntu server running on EC2 (which I didn't install myself, just picked up an AMI). So far I'm using putty to work with it, but I am wondering how to work on it with GUI tools (I'm not ...
11
votes
3answers
13k views

ssh port forward to access my home machine from anywhere

http://serverfault.com/questions/303937/how-to-make-freebsd-box-accessible-from-internet I want to understand this whole process of port forwarding. I read so many things but failing to understand ...
11
votes
5answers
51k views

What is the right file permission for a .pem file to SSH and SCP

I have tried to SSH into my AWS ubuntu server and copy the directory to my local machine. Throughout the process I experience different file permission errors (noted below). Is there one specific ...
11
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2answers
1k 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 ...
11
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2answers
14k views

Multiple 'Host *' in ssh_config?

My understanding of the way ~/.ssh/config works is that each 'Host ' line takes effect for any host matching after that point in the config file. I have a number of personal servers and work servers ...
11
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4answers
342 views

Is my SSH key paired with me as a human, or with my user account on one machine?

In the past few days, I have been trying to acquaint myself with SSH, and I hope that I've understood it. One question remains, however -- is my key associated with me (as the user) or my user ...
11
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1answer
19k views

How to wget a file to a remote machine over SSH?

I'd like to basically pipe a wget command to a file on a remote server over SSH. How can I do this? I know I could simply ssh into the server and have it download the file, but I'd much rather use the ...
11
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2answers
9k views

How do I sftp to a server if the username contains @ symbol

I have to sftp to a server to a specific port but the username contains the @ symbol. suppose the user is "user@domain.com" and the ftp server is just "domain.com" I will end with sftp -oPort:8777 ...