How to establish ssh key pair when “Host key verification failed”

Question

I have set up ssh key pairs between my desktop and two servers, and from the servers to my desktop, but after reinstalling the OS on my desktop, I can\'t re-establish the key-pa

Answer 1

When you try to connect your remote server with ssh:

$ ssh username@ip_address

then the error raise, to solve it:

$ ssh-keygen -f "/home/local_username/.ssh/known_hosts" -R "ip_address"

Answer 2

Also sometimes there is situation when you are working on serial console, then checking above command in verbose mode -v will show you /dev/tty does not exists, while it does.

In above case just remove /dev/tty and create a symlink of /dev/ttyS0 to /dev/tty.

Answer 3

Its means your remote host key was changed (May be host password change),

Your terminal suggested to execute this command as root user

$ ssh-keygen -f "/root/.ssh/known_hosts" -R [www.website.net]:4231

You have to remove that host name from hosts list on your pc/server. Copy that suggested command and execute as a root user.

$ sudo su                                                            // Login as a root user

$ ssh-keygen -f "/root/.ssh/known_hosts" -R [www.website.net]:4231   // Terminal suggested command execute here
Host [www.website.net]:4231 found: line 16 type ECDSA
/root/.ssh/known_hosts updated.
Original contents retained as /root/.ssh/known_hosts.old

$ exit                                                               // Exist from root user

$ sudo ssh root@www.website.net -p 4231                              // Try again

I Hope this works.

Answer 4

Step1:$Bhargava.ssh#

ssh-keygen -R 199.95.30.220

step2:$Bhargava.ssh #

ssh-copy-id hostname@199.95.30.220

          Enter the the password.........

step3: Bhargava .ssh #

ssh hostname@199.95.30.220

Welcome to Ubuntu 14.04.3 LTS (GNU/Linux 3.13.0-68-generic x86_64) * Documentation: https://help.ubuntu.com/ Ubuntu 14.04.3 LTS server : 228839 ip : 199.95.30.220 hostname : qt.example.com System information as of Thu Mar 24 02:13:43 EDT 2016 System load: 0.67 Processes: 321 Usage of /home: 5.1% of 497.80GB Users logged in: 0 Memory usage: 53% IP address for eth0: 199.95.30.220 Swap usage: 16% IP address for docker0: 172.17.0.1 Graph this data and manage this system at: https://landscape.canonical.com/ Last login: Wed Mar 23 02:07:29 2016 from 103.200.41.50

hostname@qt:~$

Answer 5

Task Passwordless authentication for suer.

Error : Host key verification failed.

Source :10.13.1.11 Target : 10.13.1.35

Temporary workaround :

[user@server~]$ ssh user@10.13.1.35 The authenticity of host '10.13.1.35 (10.13.1.35)' can't be established. RSA key fingerprint is b8:ba:30:46:a9:ab:70:12:1a:f2:f1:61:69:73:0a:19. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '10.13.1.35' (RSA) to the list of known hosts.

Try to authenticate user again...it will work.