Can't connect to port 22, Connection timed out - ssh

I just recently got into whatever you might call this stuff. I was just trying to send a java file over to the computer I ssh to. But when I went to do it, I just get told
sh: connect to host port 22: Connection timed out
lost connection
If possible I would like it explained very simply because of how new I am to this kind of stuff.

SSH to remote host(VM Ubuntu) from VS code terminal
Install VS Code with Remote Development extension pack.
Install Virtual machine (Virtual box) and Ubuntu running on it.
Check Ubuntu-Network-Settings-IPv4 address (10.0.2.15-default for VM).
Go to your virtual box Settings-Network-NAT Adapter (double-check).
Go to your virtual box Settings-Network-In Advanced-Port Forwarding.
Add this as given below and click ok and hereafter consider 127.0.1.1 for ssh.
portforwardinginVM
View the status and disable firewall settings in Ubuntu VM (ufw command).
In VS Code, View-Command Palette- Add new SSH host .
Add ssh username#127.0.1.1 and enter.
Or go to the terminal window (eg. Powershell) and type ssh username#127.0.1.1, it will ask if you want to update to host lists permanently, asking like yes/no and also your Ubuntu password to confirm.
Now try to connect to the host using username#127.0.1.1 and selecting OS like Ubuntu, then type the Ubuntu password.
That's it you are logged in to your virtual machine and can access files now from your local machine.

Related

Spyder -- Connect to remote kernel via proxy

I'm trying to connect to a remote kernel in Spyder, however the machine on which it is running is not directly accessible. Rather, to connect to it I must go through a bastion host / jumpbox as follows:
ssh -i ~/.ssh/id_rsa -J me#jumpbox me#remote which logs me directly into remote, automatically sending the connection through jumpbox.
I have python -m spyder-kernels.console running on remote, where I want to do my computing, but no way to connect to it directly since it's only accessible from jumpbox. I've tried setting up my ssh config with a ProxyJump entry which works for logging into the machine through ssh in the command line, but it appears that Spyder ignores the config file when setting up the remote kernel connection,
Is there a way to connect to this remote kernel? It appears there's a way to do this with IPython and I know I can do it with Jupyter Notebook, but I'm wondering if I can do this in Spyder.
(Related: Connect spyder to a remote kernel via ssh tunnel)
I don't know if you're still looking for an answer to this, but for future people arriving here, and for my own reference:
Yes, you can. You have to create an ssh-tunnel and connect Spyder to the kernel via localhost. For you that would look something like this:
ssh -L 3336:me#jumpbox:22 me#remote
22 is for the port your ssh server at remote is listening to. This is usually 22, unless the moderator changed this. 3336 is the port at localhost to connect to, you can choose any number you like above 1024 (which are privileged ports).
Then proceed as explained in the Spyder docs, i.e., launch the spider kernel (in the environment you want) on remote
python -m spyder_kernels.console
copy the connection file (kernel-pid.json) file to your local computer:
scp -oProxyJump=me#jumpbox remote:/path/to/json-file/kernel-pid.json ~/Desktop
/path/to/json-file you have to change to the path to the connection file (which you can find by running jupyter --runtime-dir on remote in the same environment as the spyder-kernel is running) and kernel-pid.json of course to the real file name. ~/Desktop copies it to your Desktop-folder, you can change that to wherever you want.
Connect Spyder to the kernel via "Connect to existing kernel", point it to the connection file you just copied, check the This is a remote kernel (via SSH) box and enter localhost as the Hostname, and 3336 as the port (or whichever port you changed it to).
That should do it.
Note, that, as is the case for me, your jumpbox server may break your ssh connection over which you launched the Spyder kernel, which will cause your kernel to break. So you might want to use
python -m spyder_kernels.console &
to have it run in the background, or launch it in a screen session. However, note that you cannot shutdown a remote kernel with exit, and it will keep running (see here), so you have to kill it in a different way.

How to connect with sshd?

I need to connect my laptop (Mac OS) to my Virtual Box (Debian) via sshd and then test telnet in Debian. Problem is I can't seem to connect via sshd.
I get
sshd re-exec requires execution with an absolute path
when I run
sshd root#192.xxx.xx.xx
But if I use an absolute path as suggested I get this instead:
/usr/sbin/sshd root#192.xxx.xx.xxx
Extra argument root#192.xxx.xx.xxx
What is the problem and how does one connect via sshd?
sshd is the dæmon program that listens to SSH port, then let incoming connections in.
You want to use ssh (without "d") as a client to connect to a remote machine:
usr/sbin/ssh root#192.xxx.xx.xxx

how to create reverse ssh tunnel to docker-toolbox which binds to 0.0.0.0

I recently started using docker toolbox on windows and its been quite a hard experience. A lot of things are different compared to running docker on linux as here docker is actually running inside virtual machine.
one of the issues i was still not able to resolve is how to create reverse ssh tunnel to my docker-toolbox VM and bind it to 0.0.0.0 (or to docker0 interface)
i have docker toolbox 1.10.2 and am running windows 7.
motivation: I have mysql server running on my windows machine and i would like to connect to it from my docker containers.
problem: i first tried connecting directly to 192.168.99.1 (the ip of my host windows box inside my containers) ... however that doesnt work. i think the reason is that my windows box is blocking all external connections to it. i cant change windows firewall settings as those are managed by domain.
workaround: i setup ssh connection to my VM (boot2docker inside virtualbox) with putty and i try to setup reverse proxy:
i check the "Remote ports do the same" under SSH tunnels in putty
source port i enter 0.0.0.0:3306
destination i enter localhost:3306
i check "remote" radio button
i then ssh to boot2docker ... netstat -natp | grep 3306 shows me its actually bound to 127.0.0.1
i opened /usr/local/etc/ssh/sshd_config
i set GatewayPorts yes
i restard sshd with /usr/local/etc/init.d/openssh restart
i get disconnected ... when i create new connection and netstat -natp | grep 3306 i see 3306 is still bound to 127.0.0.1 only
same settings in putty (and in sshd_config) work on my debian box ... but not inside boot2docker.
any idea whats wrong ? thanks a lot.

ssh server connect to host xxx port 22: Connection timed out on linux-ubuntu [closed]

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I am trying to connect to remote server via ssh but getting connection timeout.
I ran the following command
ssh testkamer#test.dommainname.com
and getting following result
ssh: connect to host testkamer#test.dommainname.com port 22: Connection timed out
but if try to connect on another remote server then I can login successfully.
So I think there is no problem in ssh and other person try to login with same login and password he can successfully login to server.
Please help me
Thanks.
Here are a couple of things that could be preventing you from connecting to your Linode instance:
DNS problem: if the computer that you're using to connect to your
remote server isn't resolving test.kameronderdehamer.nl properly
then you won't be able to reach your host. Try to connect using the
public IP address assigned to your Linode and see if it works (e.g.
ssh user#123.123.123.123). If you can connect using the public IP
but not using the hostname that would confirm that you're having
some problem with domain name resolution.
Network issues: there
might be some network issues preventing you from establishing a
connection to your server. For example, there may be a misconfigured
router in the path between you and your host, or you may be
experiencing packet loss. While this is not frequent, it has
happenned to me several times with Linode and can be very annoying.
It could be a good idea to check this just in case. You can have a look
at Diagnosing network issues with MTR (from the Linode
library).
That error message means the server to which you are connecting does not reply to SSH connection attempts on port 22. There are three possible reasons for that:
You're not running an SSH server on the machine. You'll need to install it to be able to ssh to it.
You are running an SSH server on that machine, but on a different port. You need to figure out on which port it is running; say it's on port 1234, you then run ssh -p 1234 hostname.
You are running an SSH server on that machine, and it does use the port on which you are trying to connect, but the machine has a firewall that does not allow you to connect to it. You'll need to figure out how to change the firewall, or maybe you need to ssh from a different host to be allowed in.
EDIT: as (correctly) pointed out in the comments, the third is certainly the case; the other two would result in the server sending a TCP "reset" package back upon the client's connection attempt, resulting in a "connection refused" error message, rather than the timeout you're getting. The other two might also be the case, but you need to fix the third first before you can move on.
I got this error and found that I don't have my SSH port (non standard number) whitelisted in config server firewall.
Just adding this here because it worked for me. Without changing any settings (to my knowledge), I was no longer able to access my AWS EC2 instance with: ssh -i /path/to/key/key_name.pem admin#ecx-x-x-xxx-xx.eu-west-2.compute.amazonaws.com
It turned out I needed to add a rule for inbound SSH traffic, as explained here by AWS. For Port range 22, I added 0.0.0.0/0, which allows all IPv4 addresses to access the instance using SSH.
Note that making the instance accessible to all IPv4 addresses is a security risk; it is acceptable for a short time in a test environment, but you'll likely need a longer term solution.
If you are on Public Network, Firewall will block all incoming connections by default. check your firewall settings or use private network to SSL
The possibility could be, the SSH might not be enabled on your server/system.
Check sudo systemctl status ssh is Active or not.
If it's not active, try installing with the help of these commands
sudo apt update
sudo apt install openssh-server
Now try to access the server/system with following command
ssh username#ip_address
This happens because of firewall connection.
Reset your firewall connection from your hosting website.
It will start working.
After connecting to the server again add this to your (ufw) security
sudo ufw allow 22/tcp
There can be many possible reasons for this failure.
Some are listed above. I faced the same issue, it is very hard to find the root cause of the failure.
I will recommend you to check the session timeout for shh from ssh_config file.
Try to increase the session timeout and see if it fails again
My VPN connection was not enabled. I was trying all possible way to open up the Firwall and Ports until I realized, I am working from home and my VPN connection was down.
But yes, Firewall and ssh configurations can be a reason.
Try connecting to a vpn, if possible. That was the reason I was facing problem.
Tip: if you're using an ec2 machine, try rebooting it. This worked for me the other day :)
I had this issue while trying to ssh into a local nextcloud server from my Mac.
I had no issues ssh-ing in once, but if I tried to have more than one concurrent connection, it would hang until it timed out.
Note, I was sshing to my user#public-ip-address.
I realized the second connection only didn't work when I tried to ssh into it when on the same network, ie my home network
Furthermore, when I tried ssh user#server-domain it worked!
The end fix was to use ssh user#server-domain rather than ssh user#public-ip
I have experienced a couple of nasty issues that lead to these errors, and these are different from everyone else's answer here:
Wrong folder access rights. You need to have specific directory permissions on you ssh folders and files.
a. The .ssh directory permissions should be 700 (drwx------).
b. The public key (.pub file) should be 644 (-rw-r--r--).
c. The private key (id_rsa) on the client host, and the authorized_keys file on the server, should be 600 (-rw-------).
Nasty docker network configuration. This just happened to me on an AWS EC2 instance. It turned out that I had a docker network with an ip range that interfered with the ssh access granted by the security group and VPC. The docker network's range was e.g. 192.168.176.0/20 (i.e. a range from 192.168.176.1->192.168.191.254), whereas the security group had a range of 192.168.179.0/24; interfering with the SSH access.
I had this error when trying to SSH into my Raspberry pi from my MBP via bash terminal. My RPI was connected to the network via wifi/wlan0 and this IP had been changed upon restart by my routers DHCP.
Check IP being used to login via SSH is correct. Re-check IP of device being SSH'd into (in my case the RPI), which can be checked using hostname -I
Confirm/amend SSH login credentials on "guest" device (in my case the MBP) and it worked fine in my attempt.
I faced a similar issue. I checked for the below:
if ssh is not installed on your machine, you will have to install it firstly. (You will get a message saying ssh is not recognized as a command).
Port 22 is open or not on the server you are trying to ssh.
If the control of remote server is in your hands and you have permissions, try to disable firewall on it.
Try to ssh again.
If port is not an issue then you would have to check for firewall settings as it is the one that is blocking your connection.
For me too it was a firewall issue between my machine and remote server.I disabled the firewall on the remote server and I was able to make a connection using ssh.
my main machine is windows 10 and I have CEntOS 7 VBox
Search in your main machine for "known_hosts"
usually, known_host location in windows in "user/.ssh/known_host"
open it using notepad and delete the line where your centos vbox ip
then try connect in your terminal
in mac os user you can find known_hosts in "~/.ssh/known_hosts"
Make sure to ask the admin to authorize your device.
On Linux run:
sudo zerotier-cli listnetworks
if it returns status ACCESS DENIED ask the admin to authorize your node. This is mentioned here.
https://discuss.zerotier.com/t/solved-cant-join-network/1919
This issue is also caused if the Dynamic Host Configuration Protocol is not set-up properly.
To solve this first check if your IP Address is configured using
ping ipaddress,
If there is no packet loss and the IP Address is working fine try any other solution. If there is no response and you have 100% packet loss, it means that your IP Address is not working and not configured.
Now configure your IP Address using,
sudo dhclient -v devicename
To check your device you can use the 'ip a' command
For eg. My device was usb0 since I had connected the device through usb
This will configure an IP Address automatically and you can even see which one is configured. You can again check with the 'ip a' command to confirm.
This may be very case specific and work in some cases only but
check to see if you were previously connecting through some VPN software/application.
Try connecting again to the VPN. Worked in my case.
This happened to me after enabling port 22 with "sudo ufw allow ssh". Before that, I was getting a refusal from my machine when entering with ssh from another one. After enabling it, I thought it would work, but instead it showed the message "connection timed out". As I had just installed Ubuntu with the option of installing basic functions alongside, I checked whether I had the openssh-server with the command sudo apt list --installed | grep openssh-server. It turned out that Ubuntu had installed by defect the openssh-client instead. I uninstalled it and installed the openssh-server following the basic commands:
sudo apt-get purge openssh-client
sudo apt update
sudo apt install openssh-server
After that, a simple "sudo ufw allow ssh" worked perfectly and I was finally able to access the machine with an ssh command.
What worked for me was that i went to my security group and reset my IP and it worked
Here are some considerations which i took to resolve a similar issue that I had:
Port 22
IGW (Internet Gateway)
VPC
Scene 1> This is for port 22 not enabled with right configurations. If the port is set to custom or myip, the probable scene is this won't work.
Scene 2> When you delete the internet gateway, the network is created and the instance will be functional too, but the routing from the internet will not work. Hence make sure that if there is a VPC, it has an Internet Gateway attached.
Scene 3> Check the VPC for the subnet associations and routing table entries. This might probably tell you the cause. I found one in this kind of troubleshooting. The route used to land up in a "blackhole" (shows up in the route table section of the console). To fix this I had to check and find out my internet gateway and found the issue with the IGW.
Moral of the story: always trace backward in the network!
In my case I'm on windows, I reset my firewall settings, and it fixed
If you get any error check the basic a version control request with ssh -V and If it is not installed, install it with the sudo apt-get install openssh-server command.
Check your virtual machine ssh connection with sudo service ssh status at console.
Check "Active" rows and if write a inactive(dead) the console write sudo service ssh start
Result: Now you can check your connection with sudo service ssh status command and send ssh connection request.
Reset the firewall and reboot your VPS from your hosting service, it will start working perfectly fine
check whether accidentally you have deleted the default vpc or default subnets ,while creating your own vpc and subnets.
I have done this mistake while creating vpc, hence got this error while connecting via ssh.
alos check whether u have attched IGW to public subnets.
Its not complicated.
First, go disable your firewall(USE YOUR CONTROL PANEL)after you check if your openssh is active.
Disable firewall, then use putty or any alternative to basically disable using this command sudo ufw disable
try now
Update the security group of that instance. Your local IP must have updated. Every time it’s IP flips. You will have to go update the Security group.

How can I set up SSH tunneling to access a webserver behind a firewall?

How would I access a webserver behind a firewall? I'm developing an application for this webserver which is not yet open to the public.
Someone walked me through this before, so I know it can be done. However, it has been about four months and I haven't been able to do it again.
I'm using Putty to connect to the remote machine. From that machine I can open the site http://dev.server.address:83 using Firefox. However, I want to be able to open http://localhost:80 on my machine to see the same page.
I'm using the server address and port 83 for the "source port"
I'm using localhost:80 for the "destination port"
You need to enter "80" into Source port and dev.server.address:83 to Destination.
[And don't forget to click the "Add" button before you leave the configuration screen. If you don't click that, PuTTY doesn't actually create a tunnel. I fell for that gotcha quite a few times myself]
Have you tried using 127.0.0.1:80 instead of localhost:80? I don't use PuTTY, but when I use SSH on my machine, I have to specify 127.0.0.1 instead of localhost.
Do you have a webserver running on your local machine? If that is listening on port 80 http://localhost:80 wont work. Alternatively try mapping the source to a different port (12345 for eg.) and then try http://localhost:12345 in your browser.
On Linux you can also make it happen with:
$ ssh -f -R 83:localhost:80 user#dev.server.address
Provided that you have an SSH account named "user".