Secure Shell (SSH) is a protocol primarily for encrypted shell connections. This tag is also used for questions about sshd and openssh, the two standard applications for using SSH.

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11
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4answers
4k views

“Virtual hosts” for SSH [duplicate]

We have a remote Xen server running a lot of guest machines (on Linux), with only a couple of IPs available. Each guest machine should be directly accessible by the SSH from the outer world. Right ...
30
votes
12answers
51k views

Can't get SSH public key authentication to work [closed]

My server is running CentOS 5.3. I'm on a Mac running Leopard. I don't know which is responsible for this: I can log on to my server just fine via password authentication. I've gone through all of ...
17
votes
7answers
16k views

Monitor an incoming SSH session in real time

Is there any linux software to monitor an incoming ssh session. At a previous job I was told that if you ever needed support from Red Hat for example you could have them SSH into your machine and you ...
9
votes
3answers
3k views

Logging a “persons” activity in Linux

So I've read many of the posts related to this and have just come up more confused than before. There are recommendations for various tools including ttyrec, snoopy, acct, rootsh, sudosh, ttyrpld, ...
13
votes
6answers
17k views

When IP aliasing how does the OS determine which IP address will be used as source for outbound TCP/IP connections?

I have a server running Ubuntu Server with four IP addresses aliased on a single NIC. eth0 192.168.1.100 eth0:0 192.168.1.101 eth0:1 192.168.1.102 eth0:2 192.168.1.103 (Using ...
26
votes
5answers
33k views

Is it possible to use rsync over sftp (without an ssh shell)?

Rsync over ssh, works great every time. However, trying to rsync to a host which allows only sftp logins, but not ssh logins, provides the following error: rsync -av /source ssh ...
8
votes
1answer
11k views

Authenticate Linux sshd with TACACS+ (Cisco ACS)

Our network engineering team uses multiple linux servers for syslog collection, configuration backups, tftp, etc... We want to use TACACS+ on a Cisco ACS machine as our central authentication server ...
8
votes
3answers
2k views

Is SSH logging capabilities equivalent to su logging for private/public key authentication?

Here at work, we have a non-root shared login account on UNIX that is used to admin a particular application. The policy is to not allow direct logins to the shared account; you must login as yourself ...
4
votes
3answers
3k views

Can't change assigned key pair on amazon ec2 instance

I can't seem to find the option to assign a newly created key pair to an amazon ec2 instance after deleting away the original key pair. I wanted to "deny" the first key pair from access to the ...
5
votes
4answers
8k views

SSH remote port forwarding failed

Follow-Up: It looks like the rapid series of disconnects coinciding with a few months of running each server is probably coincidental and just served to reveal the actual problem. The reason it ...
5
votes
2answers
7k views

No TTY present when running commands over SSH in here-document

I'm trying to run a command over SSH like this in a here-document: ssh example.com <<END sudo /etc/init.d/apache2 reload END Which normally works except when I'm trying to run something that ...
5
votes
15answers
5k views

Best way to mount a Linux filesystem on Windows over the Internet?

I was going to attempt Samba over SSH, any better ideas? Edit: My mom has been bugging me to do some offsite backing up of her files. She currently uses Norton Ghost. I have a VPS that I use for ...
4
votes
4answers
4k views

Yum install php-pecl-memcached - No package found (Have epel-release-6-8.noarch.rpm)

I believed I've downloaded and updated the EPEL rpm but I can't install php-pecl-memcached.. I'm very new to this, any help is appreciated. #rpm -Uvh epel-release-6-8.noarch.rpm warning: ...
4
votes
4answers
2k views

root locked out of EC2

I was in the process of disabling root logins on an AWS EC2 instance. Right after setting PermitRootLogin no and restarting sshd, I closed the terminal on accident -- before setting up users with sudo ...
3
votes
3answers
376 views

Block interactive SSH sessions while allowing certain commands

How would one only allow certain commands to be run via SSH and block interactive sessions? rsync.net does this as well as bakop.com. I.e. this would work: ssh <user@host> mkdir test scp ...
2
votes
2answers
852 views

Possibility of WAN Optimization for SSH traffic

While I do understand that SSH by itself is a very low bandwidth utilizing protocol, it is sometimes choking up bandwidth during peak hours in our office environment. I want to know if at all it is ...
1
vote
3answers
262 views

Username based SSH proxy

I'm trying to mux between two ssh servers based on incoming username i.e. ssh user1@testserver will go to one sshd instance and user2@testserver goes to another. Can this be done?
1
vote
1answer
2k views

Anonymizing OpenVPN Allow SSH Access to Internal Server

I'm using an anonymizing VPN, but want SSH access to internal computer. How do I access my internal computer through SSH? When I do ssh 98.123.45.6, the connection times out. IP address from cable ...
0
votes
4answers
5k views

Monitor file copies with SCP done via SSH

Is there a way to keep a log of the files copied using SCP? I am administering a server which contains some files that should be monitored (in a specific folder and its subfolders), so when someone ...
227
votes
19answers
301k views

How do I tell Git for Windows where to find my private RSA key?

My GIT setup runs fine in Linux, but when I try to set things up under Windows (using Git for Windows and TortoiseGit), I don't know where to put my private ssh key (or, better still, how to tell ssh ...
72
votes
3answers
63k views

how to disable SSH login with password for some users?

On Linux (Debian Squeeze) I would like to disable SSH login using password to some users (selected group or all users except root). But I do not want to disable login using certificate for them. ...
42
votes
8answers
108k views

“Add correct host key in known_hosts” / multiple ssh host keys per hostname?

Trying to ssh into a computer I control, I'm getting the familiar message: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @ ...
31
votes
8answers
5k views

What are best practices for managing SSH keys in a team?

I work with small teams (<10) of developers and admins with the following characteristics: Most members of the team have >1 personal computer, most of which are portable Team members have access ...
31
votes
3answers
24k views

What's best practice for communication between Amazon EC2 instances?

I've been setting up Amazon EC2 instances for an upcoming project. They are all micro instances, running Ubuntu Server 64bit. Here's what I've setup so far: Web Server -- Apache Database Server ...
62
votes
1answer
32k views

How do I change my private key passphrase?

I have an existing public/private key pair, the private key is password protected, the encryption may be either RSA or DSA. These keys are the kind you generate with ssh-keygen and generally store ...
23
votes
4answers
8k views

Centralized management system for SSH keys?

We are looking to switch to key-based management of SSH logins, and wonder if there any key-management systems which would allow us to centrally manage the access keys world-wide. The system should ...
23
votes
7answers
31k views

How do I run a local bash script on remote machines via ssh?

I am looking for a way to push configuration from one central machine to several remote machines without the need to install anything on the remote machines. The aim is to do something like you ...
52
votes
5answers
45k views

“POSSIBLE BREAK-IN ATTEMPT!” in /var/log/secure — what does this mean?

I've got a CentOS 5.x box running on a VPS platform. My VPS host misinterpreted a support inquiry I had about connectivity and effectively flushed some iptables rules. This resulted in ssh listening ...
12
votes
5answers
20k views

Using SSH to remotely start a process

I have written a script that I am using to push and deploy a new service to several machines under my control, and in order to execute the process I am using ssh to remotely start the process. ...
8
votes
3answers
17k views

How to setup ssh tunnel to forward ssh?

I have computer with Ubuntu behind router that I can't configure. However I want to have ssh access to that computer. I think it is possible with ssh tunneling, but I don't know how to do it. I have ...
8
votes
7answers
5k views

BASH shell session logging on remote host

What's the best method of logging a BASH shell session to a file on the host machine? The preferred output format would be equivalent to PuTTY's "printable output" log setting, as viewed by the user ...
54
votes
5answers
7k views

I accidentaly forbid SSH connection to a remote server… What's next?

Let's say it again, we all make mistakes, and I have just made one. A brief history: I was doing some stuff on a VPS (Debian) I'm renting, when I noticed some strange behaviour. Using the netstat ...
17
votes
3answers
1k views

Is it possible to SSH access a server with a misconfigured subnet?

We have a server where one of our engineers misconfigured the subnet and now we are locked out of this server and the only access that I know of would work is a serial console from IDC (it means ...
13
votes
9answers
6k views

SSH server zero-day exploit - Suggestions to protect ourselves

According to the Internet Storm Center, there seems to be a SSH zero-day exploit out there. There is some proof of concept code in here and some reference: ...
22
votes
6answers
62k views

How to remove strict RSA key checking in SSH and what's the problem here?

I have a Linux server that whenever I connect it shows me the message that changed the SSH host key: $ ssh root@host1 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: ...
16
votes
4answers
5k views

Is it possible to get OpenSSH to log the public key that was used in authentication?

I have a production system where several different people are allowed to log in to a single account - the account is for the application and not for the person as we don't have personal accounts on ...
10
votes
6answers
40k views

Linux closing connection after successful login

I am working on a server with Debian 5.2.2. Barely having any administrative knowledge with Linux, I think I screwed something up. I used apt-get update and apt-get upgrade to get everything up to ...
8
votes
4answers
714 views

Remote Root Login

I know one of the first things you do to secure a server is disallowing remote root login. Passwords are pretty weak; what do people think of only allowing root login via ssh keys or other ...
5
votes
4answers
5k views

Running git pull from a php script

I was trying the Perfect Workflow, with Git, GitHub, and SSH, but it seems i can't run git pull. I've tried git status and it's fine. When i git pull 2>&1 i get: error: cannot open ...
5
votes
2answers
4k views

How do I setup ssh with both private key and password?

How do I setup ssh with both private key and password? In /etc/ssh/sshd_config, I currently have: RSAAuthentication yes PubkeyAuthentication yes PasswordAuthentication yes But apparently this ...
4
votes
3answers
8k views

How to assign a hostname to SSH tunnel

I'm using ssh root@my.server.ip -g -L 4321:localhost:28017 to establish a tunnel from my MacBook to my dedicated server at my hosting provider. It works well. Now I want to access several admin sites ...
9
votes
4answers
2k views

Reverse SSH tunnel: how can I send my port number to the server?

I have two machines, Client and Server. Client (who is behind a corporate firewall) opens a reverse SSH tunnel to Server, which has a publicly-accessible IP address, using this command: ssh -nNT ...
7
votes
5answers
24k views

Disable usage of console-kit-daemon in Ubuntu

I administrate several Ubuntu 9.04 servers, and everytime I log in, I get the Landscape utility printout with server stats, etc. I really don't need this and it slows down my logins considerably. ...
5
votes
2answers
5k views

ssh fails to execute remote command when run from cron bash script - works from CLI

I have a script, written in bash, which runs from cron. One of the first things it does is SSH to a remote host and retrieve a list of files in a directory. Everything works fine when run from the ...
20
votes
6answers
24k views

protocol version mismatch — is your shell clean?

When following the instructions to do rsync backups given here: http://troy.jdmz.net/rsync/index.html I get the error "protocol version mismatch -- is your shell clean?" I read somewhere that I ...
14
votes
3answers
11k views

Connect through SSH and type in password automatically, without using a public key

A server allows SSH connections, but not using public key authentication. It's not within my power to change this at the moment (due to technical difficulties, not organizational) but I will get on it ...
9
votes
9answers
57k views

How can I map a SFTP to a Drive, natively in Windows

Today I saw that Vista and Win7 (which I am using) have the option to map ftp natively, according to this article: http://cybernetnews.com/cybernotes-map-a-ftp-to-a-drive-in-windows/ But I need to ...
7
votes
3answers
4k views

Running 'sudo' over SSH

I'm writing a script which is to log onto a bunch of remote machines and run a command on them. I've set up keys so the user running the script does not have to type the password of each machine, but ...
6
votes
4answers
3k views

SSH from A through B to C, using private key on B

I'm looking for a simple way to SSH from my local machine, A, through a proxy, B, to a destination host, C. The private key that goes with the public key on C is on B, and I can't put that key on my ...
4
votes
3answers
6k views

Escaping spaces in a remote path when using rsync over a remote SSH connection

When using SSH to connect rsync to a remote server, how do you escape spaces and such in the remote path? A simple backslash escapes the space for the local bash prompt, but on the remote machine the ...