Secure Shell (SSH) is a protocol primarily for encrypted shell connections.

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4
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2answers
11k views

execute su -c over ssh

I am trying to check the BIOS version of a server over SSH, a command that requires root privileges: ssh remote-server su -c dmidecode but this of course fails with the error: standard in must ...
3
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1answer
1k views

SSH from Windows to Linux with AD certificates

I have a Windows client machine connected to Active Directory and a Linux server also connected to Active Directory (through PAM w/ LDAP), and I want to be able to do password-less SSH from Windows to ...
3
votes
6answers
2k views

Same command on multiple servers

I'm just wondering if there is any fellow sysadmin with the need to execute one command on multiple servers. If so, what technique are you using? I have grown tired to ssh-ing to 3-5 servers and ...
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2answers
3k views

How does one determine active SSH and SAMBA connection counts?

I have a server that I use infrequently, so I'd like to cron a job to shutdown daily if no users are logged in via SSH and SAMBA shares. How can I determine how many active SSH connections there are, ...
11
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3answers
10k views

What options can be put into a SSH authorized_keys file?

I found this article on options that can be put before a key in the authorized_keys file. I was wondering though, are there more? Options listed in the article are from="domain" ...
10
votes
5answers
19k views

Out of nowhere, ssh_exchange_identification: Connection closed by remote host

I am running Ubuntu 10.10 on a remote box. I ssh to it everyday without issues but today out of the blue, I get the following error: ssh_exchange_identification: Connection closed by remote host If ...
10
votes
8answers
17k views

Why can't I ssh into my new EC2 Instance?

I created a new instance (tiny, 64 bit AMI linux from Amazon) Created a new key pair called "mir". I downloaded mir.pem and put it in my ~/.ssh folder. I even did ssh-add mir.pem. Then I tried to ...
8
votes
4answers
17k views

SSH X11 not working

I have a home and work computer, the home computer has a static IP address. If I ssh from my work computer to my home computer, the ssh connection works but X11 applications are not displayed. In my ...
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votes
6answers
7k views

Routing all traffic thru socks proxy using ssh -D

is it any easy way to route all traffic through a ssh proxy with -D? I can configure individual specific applications to do this, but I would like a configuration that routes all the traffic on the ...
6
votes
1answer
518 views

Why does my OpenSSH key fingerprint not match the AWS EC2 console keypair fingerprint?

When I import my OpenSSH public key into AWS EC2's keyring the fingerprint that AWS shows doesn't match what I see from: ssh-keygen -l -f my_key It is a different length and has different bytes. ...
6
votes
4answers
8k views

In Fail2Ban, How to Change the SSH port number?

In my server, the ssh port is not the standard 22. I have set a different one. If I setup fail2ban, will it be able to detect that port? How can I tell it to check that port rather than port 22? The ...
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votes
2answers
3k views

How to revoke an ssh certificate (not ssh identity file!)

I've generated an ssh certificate like this: ssh-keygen -f ca_key # generate a ssh keypair for use as a certificate generate a host key ssh-keygen -s ca_key -I cert_identifier -h host_key.pub ...
6
votes
3answers
2k views

What exactly does ssh send when performing key negotiation?

When explicitly specifying identity file to ssh: ssh -i ./id_rsa ... I have these lines in ssh debug trace: debug1: Offering public key: ./id_rsa debug3: send_pubkey_test debug2: we sent a ...
5
votes
5answers
6k views

Amazon EC2 - No SSH After Reboot, Connection Refused

I've replicated this two or three times, so I'm guessing there's something wrong with what I'm doing. Here are my steps: Launch new instance via EC2 Management console using: Ubuntu Server 13.10 - ...
5
votes
5answers
1k views

Email notification about each SSH connection to Linux server

I would like to be notified about each SSH connection to the Linux (Debian) server. Already saw some methods, which proposed to add mail command into own .bashrc, but this approach seems not to cover ...
5
votes
4answers
7k views

ubuntu server, ssh, write failed: broken pipe

I'm getting some bizarre behavior with Ubuntu Server 10.04 64bit on two of our new servers (both fresh installs). I have ubuntu server (same version) deployed on 4-5 other servers without this issue. ...
5
votes
4answers
5k views

Create SSH user with limited privileges to only use Git repository

I have a git repository hosted on my SunOS server, that I remotely use through ssh git clone ssh://myUser@mydomain.com/path/to/git Now I need to add more users to be able to access that repository, ...
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votes
2answers
1k views

How can I setup OpenSSH per-user authentication methods?

I'd like to be able to have one set of users authenticating using public key auth and other users to use password authentication. Is this possible in OpenSSH on Linux? If so how do I go about it? ...
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5answers
2k views

Stop ssh client from offering all the public keys it can find?

Like most sysadmins I use openssh all the time. I have about a dozen ssh keys, I like to have a different ssh key for each host. However this causes a problem when I am connecting to a host for the ...
5
votes
5answers
2k views

SSH session drops - Does the command continue executing?

If I was running a command before the SSH connection was dropped, will the command continue executing?
4
votes
3answers
353 views

Restricting the network access of Docker container

I'm in the process of creating an SFTP only Docker container, one that will be used by multiple people for the sole purpose of uploading and managing files in their own chrooted Environment. On ...
4
votes
2answers
2k views

sshd_config ForceCommand /usr/bin/rsync error “connection unexpectedly closed”

How should ForceCommand be configured in order to allow the backup user to execute any rsync command? With ForceCommand set to /usr/bin/rsync I receive the error below: connection unexpectedly ...
4
votes
3answers
4k views

Trying to setup chroot'd rsync

I'm trying to set up a backup server. I want to chroot each user (client) to its home directory, and only allow it to use sftp and rsync. I quickly discovered that I was not the only one trying to do ...
4
votes
1answer
302 views

Is it possible to have more than one private/public key pair per user for SSH?

I need a user with more than one key-pair for SSH. Is that possible? Is that possible without having to specify which key to use on each command?
4
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2answers
4k views

Locking down git ssh server

I'd like to set up a git server over ssh, with a single SSH account for the project. All project members should have their ssh keys listed in authorized_keys. Lockdown should restrict access to only ...
4
votes
3answers
12k views

Remote Desktop over SSH to Windows 7 box

I have been using remote desktop to access a Windows 7 PC, tunneled over an SSH connection, successfully for a while now, until it suddenly stopped working. The client is also Windows 7, and I ...
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votes
2answers
2k views

Differences between SSH's tunnels and OpenVPN

I discovered that recent OpenSSH has support for tun devices. When it comes to tunnels and VPNs, I always thought the main programme was OpenVPN. Are there any advantages to using SSH tunnels? What ...
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votes
4answers
3k views

It is fair to jail my SFTP users to their home directory?

roots. I'm running an Ubuntu 9.04 (home) Server on my LAN. I currently use it to store little web apps, photos, some subversion repository and stuff like that. My (few) users are friends of mine and I ...
3
votes
2answers
8k views

SSH sessions terminate abruptly with message: Corrupted MAC on input. Disconnecting: Packet corrupt

We have a Dell PowerEdge 840 Server running CentOS 6.0 64 bit with 2GB ECC memory. When any user sshs in, after some time the session gets terminated with the output: Corrupted MAC on input. Packet ...
3
votes
3answers
4k views

Ubuntu-server: gitosis user naming convention

If you install gitosis on ubuntu-server 10.10 via apt-get: sudo apt-get install gitosis The post-install script will create a new gitosisuser. This user will be used to allow people to connect with ...
3
votes
3answers
6k views

How Ubuntu cloud version enforces the “no root login” over ssh?

I'm looking to tweak ubuntu cloud version default setup where is denies root login. Attempting to connect to such machine yields: maxim@maxim-desktop:~/workspace/integration/deployengine$ ssh ...
3
votes
4answers
955 views

How can I enable both password and public key authentication with OpenSSH

I would like for sshd to verify the users' public key and then prompt for their password, rather than just one or the other. Is this possible?
3
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2answers
2k views

iptables question: forwarding port x to an ssh port of different machine on the network

I have a Ubuntu PC, with two networks cards, acting as a router. One card eth0 is connected to internet and other eth1 is connected to LAN. I want to expose ssh ports of different hosts in LAN to ...
2
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2answers
517 views

SSH public/private key login

i'm trying to make ssh work wit pp keys. However after have followed several howto's, I still have issues with the login. Server is opensuse 12.1, client is mac. This is the verbose output: debug1: ...
2
votes
3answers
4k views

sshd running but no PID file

I'm recently started using monit to monitor the status of sshd on my CentOS 5.4 server. This works fine, but every so often monit reports that sshd is no longer running. This isn't true - I am still ...
2
votes
3answers
1k views

Basic SSH port change not working on EC2 instance

I am trying to change the port of SSH on an EC2 instance, but I am not getting this to work. What I am doing is the following: Open the file /etc/ssh/ssh_config Uncomment and change the line Port ...
2
votes
3answers
643 views

fail2ban bans me after a series of *successful* logins

I created a passwordless ssh login for one of my servers by using the authorized_keys file. The server has fail2ban on it, and I noticed that after several successful logins I could no longer log in ...
2
votes
1answer
342 views

How can I make gitosis distinguish between two users with the same username

I have a gitosis system that seems to be working correctly except for a common problem we run into where I can't distingush permissions between two users who have the same username, but different ...
2
votes
1answer
4k views

CopSSH SFTP — limit users access to their home directory only

Let me preface this by saying I've read and followed these instructions at the FAQ many times: http://www.itefix.no/i2/node/37 It does not do what the title claims... It allows every user access to ...
2
votes
1answer
884 views

Requiring SSH-key Login From Specific IP Ranges

I need to be able to access my server (Ubuntu 8.04 LTS) from remote sites, but I'd like to worry a bit less about password complexity. Thus, I'd like to require that SSH keys be used for login ...
2
votes
2answers
1k views

New to Ubuntu Server, which logs to monitor and what to do

I have been running Ubuntu Server for about four months and I learn something new everyday. Today I learned that there are many logs that i didnt know existed. When I examined these logs I was blown ...
1
vote
6answers
421 views

Ultra Secure Linux Server SSH Only

I'm setting up a secure server for my use only to store encrypted files, but it will need to be accessed from the internet. The server itself is in a secure location with no physical access which is ...
1
vote
3answers
10k views

Changing terminal colors in Ubuntu Server

I'd like to change the colors. The lime green hilighting on pale blue colored file names is killing my eyes. I'm not sure if I'm using xterm or gnome or whatever, but I would like to change the ...
14
votes
7answers
3k views

I screwed up, exit in .bashrc

I put "exit" in my .bashrc file. I don't have physical access to the machine so to connect to it I use ssh. I don't have root privileges. Every time I connect to the server, the connection ...
10
votes
4answers
8k views

Force SSH to use a specific shell

Is there any way to force SSH to use a particular shell on the remote end, regardless of what the user's default shell is? I've tried solutions akin to: ssh host.domain.com /bin/bash -c ...
9
votes
1answer
2k views

SSH Prompts for password even though private keys are available, presented to server and known to it

I've got an ubuntu desktop within a VirtualBox machine and I've got a strange behaviour with the openssh server : when my user is not already connected to the server (first ssh connexion), it ...
8
votes
1answer
563 views

Allow password access for all users except root?

I want to leave the root user enabled on my servers for convenience, and the only reason people are against the idea (that I know of) is brute-force attacks on SSH. So, is there is a way in SSH to ...
8
votes
5answers
2k views

SVN+SSH Security

I use snv+ssh with key based authentication. Right now in order for any of my svn users to access the repository through Subversion, I must set the repo files to be readable and writable on the ...
7
votes
6answers
6k views

Find out how many DNS Queries/month via WHM or SSH?

Is it possible? We have complete control over our DNS server and the server actually being pointed to. We are interested in how many DNS Queries we are currently getting, as we want to move to Ultra ...
6
votes
1answer
2k views

Reliable file transfer over slow or flaky network link

I need to transfer a number of files files over a low-quality broadband link to a server. The files are large, and take approximately 30 minutes to transfer per file. I use scp, but it sometimes ...