How does this answer the question? I landed here from a web search expecting to learn how to check the SSHD log files, not what worked for you for some problem Damn I wish readers on the Stack Exchange network would actually read and answer the question at hand, and not the question they want it to be You can start another sshd on another port.
Connect to that one. Then stop the main sshd and start a new one on port If anything fails, reboot the box using your DRAC or cloud management. You should have sshd starting on boot right?
No worries. JoelESalas The community doesn't decide which answers are accepted. Show 8 more comments. Ram Ram 2, 2 2 gold badges 10 10 silver badges 4 4 bronze badges. This answer. Other answer with green arrow is bogus. Change arrow. Why not use tail -f Would this be an issue with larger log files? See this answer: serverfault. Show 4 more comments. One of the best options, specially if you only have SSH access to a server. Debugging the connection by stopping the ssh server will drop you out of session.
Just start a new ssh daemon on a different port and test the login using that port. AttilaAntal Small correction: stopping sshd will not kill active ssh sessions. This method is a good precaution in case something goes wrong, but in theory you can easily stop and then restart sshd over ssh. ParkerKemp it doesn't kill the connection, and if everything is working as expected, you should be able to continue using it after after restarting the daemon.
The problem, however, will be if for some reason the Daemon couldn't start. Then the active session will drop. Add a comment. RedEyed RedEyed 2 2 silver badges 6 6 bronze badges. With this syntax you can use for any systemd unit — MarcoZen. I tried -u sshd and it didn't work, but -u ssh works, thanks! Cory Knutson 1, 11 11 silver badges 19 19 bronze badges.
DarwinJS He mentioned there was a security reason for this. But can't this be accomplished with an ACL for chocolatey? I mean, chocolatey already requires administrator privileges by default. But just as annoying is the fact that it makes my chocolatey installation non-portable. That user assumedly had the permissions to write to ProgramFiles or wherever, so they assumedly have the permissions to put new, malicious things there.
Also it will continue to be the place Microsoft focuses attention for preventing attacks that are discovered after our conversation today.
So the answer to "can't you just ACL it to get the same protection" is "No - Program Files is more special than that". On your second post - it is a normal and strong way to protect software that the user who installs it is not the user who uses it. So if I use automation that has full local admin on servers to install the software and then the software runs without admin - the attack vector of initial installs and maintenance is not there. However, even in situations where the user is an admin and uses the machine regularly - UAC prevents many of those challenges as long as it is not disabled.
In the case of SSH server - it is running under local system and not associated with any user - so that hacking vector is blocked. Also if you look at this latest release of winopenssh the entire ssh-agent implementation and the use of psexec. I installed openssh via chocolatey today.. Check your Program Files folder just in case.
But I recall logging was disabled for some time at one point. I have similar issue. I would like to change the logs location to some other drive.
How can I do that? Below is the config. Also in the event log. Sometimes when debugging a server configuration it is necessary to track the client, too.
That allows viewing of the exact configuration options that will actually be used by the client for a particular connection. Client configuration is determined by run-time options, the user's own configuration file, or the system-wide client configuration file, in that order, whichever value is first.
With sftp 1 the options are also passed to ssh 1. A proper client will show the details of the failure. And for a bad cipher, a proper client might show something like this when trying to foist an arcfour cipher on the server:. Sometimes when troubleshooting a problem with the client it is necessary to turn to the server logs.
In OpenSSH 6. In that case, the client might not provide much information beyond a vague message that the server unexpectedly closed the network connection. The server logs will, however, show what happened:. The error message in the server log might not say which MACs or ciphers are actually available. For that, the extended test mode can be used to show the server settings, in particular the MACs or ciphers allowed.
For more details and options, see the previous section on "Debugging a server configuration" above. One solution there is to upgrade the client to one that can handle the right ciphers and MACs. Another option is to switch to a different client, one that can handle the modern ciphers or MACs. As of the time of this writing, it looks like pretty much every failure of key-based authentication described on mailing lists and forums is solved by addressing either or both of those two situations.
So, when encountering the error message "Permision denied publickey,keyboard-interactive ", or similar, see the section on Public Key Authentication. Then see the section on authorized keys in the manual page for sshd 8. A very rare third case is if the public and private key files are not from the same key pair. As mentioned in the section on Public Key Authentication , the public and private keys need to match.
That is because even before the SSH client uses private key cryptographically, it looks at the file name of the proposed private key and then sends the public key matching that same name, if it exists. Note that as mentioned above there are usually other causes to that same error message besides having mismanaged the public key file on the client machine.
The file names for both parts of each key pair have to be kept organized so that the contents match. As for a solution, the way out in the long term is to more carefully manage the keys and their file names. It is solved on the short term by deleting the offending public key file or using the private key to regenerate a new one, overwriting the offending one. Again, this is an unusual edge case and not a common cause of that error.
When there are multiple keys in the authentication agent, the client will try them on the server in an unpredictable order.
If the client happens to cycle through enough of the wrong keys first and hits the server's MaxAuthTries limit before finding the right key, the server will naturally break off the connection with an error message about too many authentication failures:. If you see this error, you can remove keys one at a time from the agent, using ssh-add 1 with the -d option, until there is just the right key left. Without existing corresponding public key files, the private keys cannot be removed individually from the authentication agent, but the whole lot may be removed all at once using the -D option instead.
However, is not always practical to do either when many servers are used frequently and the agent needs to be kept well-stocked.
Each key gets an annotation which says whether or not the key file was supplied by the user, either in the configuration file or as a run-time argument. The client prefers keys that were specified in the configuration and are also currently in the agent. Then it will try try them in the order in which they were supplied. Another way around this error is to limit the client to trying only a specific key using the IdentitiesOnly configuration directive in conjunction with the IdentityFile configuration directive.
The latter points explicitly to the right key. Both can be added either as run-time options or in the client's configuration file. Or the client configuration file could have something like the following added instead near the top:. So then the server could be reached with either the short name or the fully qualified domain name, whatever names are listed under the Host directive.
Remember that options are selected from the client configuration file on a first-match basis. The most common problem seems to be bad directory permissions. The chroot directory, and all directories above it, must be owned by root and not writable by any other user or group. Even though these directories' group memberships do not have to be root, if any of them is not root then it must not be group writable either.
Failure to use the correct ownership will result in not being able to log in with the affected accounts. The errors when login is attempted will look like this from the client side:. Check the directory permissions for the chroot target and all directories above it. If even one is off it must be fixed so that it is owned by root and not writable by any others. There are many, many routes to get there.
Here are two was to set up chroot permissions:. Then chroot the account to the parent directory and combine that with an alternate starting directory working from the user name token with the -d option for the SFTP server.
Then when the account connects it will see only its own directory and no other parts of the system. The SFTP connection will drop if there are any extraneous data either direction on stdin , from the client or the server.
There the output, which would be stdout on the server, is received by the client on stdin , but matches no correct protocol and thus causes the client to disconnect.
So, even in the case of using the RC scripts, the response from the server must remain 8-bit clean or an error will occur:.
That one message will be the main clue. Increasing the verbosity of the SFTP client with -v won't provide more relevant information. Also, the standard logs on the server will only show that the client disconnected and not provide any information why. At higher levels of logging, some extraneous reads and corresponding discards might be noticed but that is all. If an RC script does produce output, it must be redirected to a system log, to a file, or sent to stderr instead of stdout.
Regular interactive SSH connections are not disturbed by use of stdout and the client will just display whatever is sent. The same restriction goes for any other part of the SSH service which runs over stdin and stdout , such as ProxyJump or some uses of ProxyCommand. So another example of potential interference would be when using LocalCommand with the client to specify a command to execute on the local machine after successfully connecting to the server. Any output from it also needs to be redirected to stderr.
If LocalCommand ends up interfering with ProxyJump then the connection will appear to hang at the stage when stdout gets used.
Mar 19 eee sshd[]: Server listening on 0. Mar 19 eee sshd[]: Server listening on :: port Server listening on 0. Server listening on :: port Below is a log excerpt showing how the default log looks after some failed attempts Mar 19 server sshd[]: Failed password for root from Successful logins By default, the server does not store much information about user transactions.
So here is an example of a successful SSH login: Mar 14 server sshd[]: Accepted password for fred from Mar 14 server sshd[]: Accepted publickey for fred from
0コメント