SSH has been working fine for the last few weeks since I got my new PC. I've had no problems but today I started getting:
ssh: connect to host github.com port 22: resource temporarily unavailable
I did some googling and found that there is a common issue with WSL which sometimes causes this, but I'm unable to SSH from my bash shell, or from cmd/powershell.
This is the part that confuses me, if I do: ssh -T git#192.30.253.113 I am prompted for the password to my key, it successfully authenticates and responds with "Hi alexmk92! You've successfully authenticated".
Great, that at least proves that my firewall isn't blocking SSH on port 22. But why does git#github.com throw the resource failed error? My initial thought is that this could be a DNS problem.
So I tried to configure my network adapter to use Google's DNS server (8.8.8.8 and 8.8.4.4) I even configured the IPV6 DNS servers just in case. Following this I did an ipconfig /flushdns, attempted to connect via git#github.com again and BAM the same result, however git#192.30.253.113 still works.
I'm guessing another potential cause is that github.com is behind a load balancer and one of the IP's on the cluster could be black-listed somewhere on my machine? I'm just pulling guesses out of thin air now, any help would be greatly appreciated, this is driving me insane.
After some further Googling it turned out that my machine did not have a hosts entry for github.com and it was unable to automatically resolve it.
In Windows Subsystem for Linux I created a ssh config file
touch ~/.ssh/config
(for some reason the base distro of Ubuntu 18.04 on the windows marketplace didn't have one) I then had to make sure the file permissions were correct:
chmod 755 ~/.ssh/config
Once the file was created, I edited it with
sudo nano ~/.ssh/config
and added github.com as a Host.
Host github.com
Hostname ssh.github.com
Port 22
Upon saving, I ran
sudo /etc/init.d/ssh restart
and attempted
ssh -T git#github.com
Everything now seems to be working.
In my case my ISP did not allow ssh, so it was not working from cmd and wsl both. Got around it using vpn
To have successful SSH connection to Github, SSH key has to be import into Github
Open Git bash or Terminal
Run the command ssh-keygen
Choose all default option
A private and a public key gets generated in the folder * < user_home>/.ssh/*
Login to Github.com
Navigate to account settings
Choose item "SSH and GPG Keys" from the side navigation bar
click added new SSh key
Copy and save public key content from * < user_home>/.ssh/id_rsa.pub *
I'm sorry to have to ask this question, but I feel like I've tried every answer so far on SO with no luck.
I have my local machine and my remote server. Jenkins is up and running on my server.
If I open up terminal and do something like scp /path/to/file user#server:/path/to/wherever then my ssh works fine without requiring a password
If I run this command inside of my Jenkins job I get 'Host Key Verification Failed'
So I know my SSH is working correctly the way I want, but why can't I get Jenkins to use this SSH key?
Interesting thing is, it did work fine when I first set up Jenkins and the key, then I think I restarted my local machine, or restarted Jenkins, then it stopped working. It's hard to say exactly what caused it.
I've also tried several options regarding ssh-agent and ssh-add but those don't seem to work.
I verified the local machine .pub is on the server in the /user/.ssh folder and is also in the authorized keys file. The folder is owned by user.
Any thoughts would be much appreciated and I can provide more info about my problem. Thanks!
Update:
Per Kensters suggestion I did su - jenkins, then ssh server, and it asked me to add to known hosts. So I thought this was a step in the right direction. But the same problem persisted afterward.
Something I did not notice before I can ssh server without password when using my myUsername account. But if I switch to the jenkins user, then it asks me for my password when I do ssh server.
I also tried ssh-keygen -R server as suggested to no avail.
Try
su jenkins
ssh-keyscan YOUR-HOSTNAME >> ~/.ssh/known_hosts
SSH Slaves Plugin doesn't support ECDSA. The command above should add RSA key for ssh-slave.
Host Key Verification Failed
ssh is complaining about the remote host key, not the local key that you're trying to use for authentication.
Every SSH server has a host key which is used to identify the server to the client. This helps prevent clients from connecting to servers which are impersonating the intended server. The first time you use ssh to connect to a particular host, ssh will normally prompt you to accept the remote host's host key, then store the key locally so that ssh will recognize the key in the future. The widely used OpenSSH ssh program stores known host keys in a file .ssh/known_hosts within each user's home directory.
In this case, one of two things is happening:
The user ID that Jenkins is using to run these jobs has never connected to this particular remote host before, and doesn't have the remote host's host key in its known_hosts file.
The remote host key has changed for some reason, and it no longer matches the key which is stored in the Jenkins user's known_hosts file.
You need to update the known_hosts file for the user which jenkins is using to run these ssh operations. You need to remove any old host key for this host from the file, then add the host's new host key to the file. The simplest way is to use su or sudo to become the Jenkins user, then run ssh interactively to connect to the remote server:
$ ssh server
If ssh prompts you to accept a host key, say yes, and you're done. You don't even have to finish logging in. If it prints a big scary warning that the host key has changed, run this to remove the existing host from known_hosts:
$ ssh-keygen -R server
Then rerun the ssh command.
One thing to be aware of: you can't use a passphrase when you generate a key that you're going to use with Jenkins, because it gives you no opportunity to enter such a thing (seeing as it runs automated jobs with no human intervention).
This shouldn't be this hard. I cannot connect to new AWS EC2 instance via SSH clients. I am connecting from a Win 7 box.
Instance OS: Debian 6
AMI: debian-squeeze-i386-20121119-e4554303-3a9d-412e-9604-eae67dde7b76-ami-1977f070.1(ami-a121a6c8)
User: tried root and also ec2-user
Using .pem keypair that AWS generated and I downloaded
Confirmed security group and Key Pair Name on instance
SSH port 22 is OPEN: Nmap says so and Telnet gets a welcome reply
Using 3 different clients: all clients connect ok
PuTTY replies: Server refused our key
MindTerm Java browser add-in replies: Authentication failed, permission denied
Bitvise SSH replies: Attempting 'publickey' auth; auth failed;
Rebooted instance, wash, rinse, repeat...
REBUILT new instance and new keypair, wash, rinse, repeat...
Connecting isn't the issue. Why would the instance not accept the .pem file as the password? Is there an additional step I am missing? I followed EVERY frigging guide I could Google. AWS support is a joke. stackoverflow to the rescue...
TIA.
According to the debian wiki which has documentation on the AMI you are using, the username you need to use to login is 'admin'.
I have had many issues with connecting to EC2 via ssh.
ssh -i the-keypair-filename root#yourdomain.com
- Keypair file must be in same directory.
- I just used terminal to connect.
Make sure you generate or assign the keypair when launching the instance.
Also you can verify the keypair you have set in the AWS Management Console, this is done by selecting the running instance and then looking for "Key Pair Name:".
I hope this is helpful.
My problem was that I didn't add a volume that was expected in the fstab file so the server didn't start fully and the sshd daemon wasn't running.
Check with:
telnet HOST 22
Check the server logs to make sure it starts properly before you waste lots of time like I did.
Amazon Linux AMIs that use ec2-user password are listed at the bottom of this page.
http://aws.amazon.com/amazon-linux-ami/
Check that you are using one of those if trying to use ec2-user, or check the documentation for the AMI you are using.
Teri
Try using the "admin" username and ignore the username suggested by Amazon.
I had the similar problem and I have solved the issue by following approach.
1) Edited the knife.rb file in my chef folder i.e. :\Users\Administrator\chef-starter\chef-repo.chef\knife.rb as bellow:
knife[:aws_access_key_id] = "xxxxxxxxxxxxxxxxxxxx"
knife[:aws_secret_access_key] = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
knife[:region] = 'ap-southeast-1'
knife[:aws_ssh_key_id] = "ChefUser"
knife[:ssh_user]="ec2-user"
In the command prompt, issued the command to create an ec2-server:
knife ec2 server create -r "role[webserver]" --image ami-abcd1234 --flavor t1.micro -G ChefClient -x root -N server01 -i H:\Chef-files\ChefUser.pem
Note that, even though I had given all the details in the knife.rb file, I had to give the .pem file path in coomand line through -i option. That solved my problem.
Check, if the solution of mine helps you.
Cheers,
Chandan
Logging in as "ubuntu" worked for me:
ssh -i private_key.pem ubuntu#myubuntuserver
Hope this helps
--Erin
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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.
I had set up a ubuntu instance with rails package and also deployed my app, it is working fine.
But when i try to do SSH I its not allowing me for the remote login and throws errors like host key verification failed.
The problem seem to be persisting, kindly recommend the solution and I have attached a elastic IP to that and I am not able to see the public DNS, my instance is running in singapure region.
You may need to turn off StrictHostChecking by adding this option to ssh command line
-o StrictHostKeyChecking=no
As answered in more detail in your cross posted question on ServerFault: https://serverfault.com/questions/342228/unable-to-connect-to-the-aws-ec2-instance-host-key-verification-failed/342696#342696
Basically your ec2 elastic IP has previously been used with another server instance and your ssh client known hosts file does not match the new one for this IP. Remove offending line in known_host file. (More detail on Server Fault answer)
You need to log in to your instance with the private key that you set it to use.
Depending on your instance, the user might vary
ssh -i [private key file] [user]#[host]
Where user could be one of the following in my experience (or possibly others)
root
ec2-user
ec2user
bitnami
ubuntu