The Ultimate Guide to Fixing “Server’s Host Key has been Rejected by User” Error

Welcome, Dev! It’s not uncommon to face errors and issues when working with servers. One of the most frustrating errors that you may encounter is the “Server’s host key has been rejected by user” error. This error can be a nightmare for anyone who relies on server access for their work. However, fret not! In this comprehensive guide, we will explain the error in detail and provide you with simple solutions to fix it.

Understanding the “Server’s Host Key has been Rejected by User” Error

Before we dive into the solutions, let us first understand what the error message means. This error usually occurs when you try to connect to a server through SSH or SFTP. SSH (Secure Shell) is a network protocol that allows secure access to a remote server. SFTP (Secure File Transfer Protocol) is an extension of SSH that provides a secure way to transfer files.

When you connect to a server for the first time, the server sends its public key to your computer. Your computer then stores this key in a file called “known_hosts”. This helps your computer identify the server the next time you try to connect to it. However, if the server’s public key changes, your computer will not recognize it, and you will encounter the “Server’s host key has been rejected by user” error.

The Possible Causes of the “Server’s Host Key has been Rejected by User” Error

There can be several reasons why you may encounter this error. Here are some of the most common ones:

Solutions to Fix the “Server’s Host Key has been Rejected by User” Error

Solution 1: Remove the Server’s Public Key from Your Computer

If you are sure that the server’s public key has changed, you can remove the old key from your computer’s “known_hosts” file. Here’s how:

1. Open your terminal or command prompt.
2. Type the following command:

ssh-keygen -R <hostname or IP address>

3. Replace <hostname or IP address> with the hostname or IP address of the server that you are trying to connect to.
4. Press Enter.
5. You should see a message that the old key has been removed.
6. Try to connect to the server again.

Solution 2: Add the Server’s New Public Key to Your Computer

If the server’s public key has changed, you can add the new key to your computer’s “known_hosts” file. Here’s how:

1. Open your terminal or command prompt.
2. Type the following command:

ssh-keyscan <hostname or IP address> >> ~/.ssh/known_hosts

3. Replace <hostname or IP address> with the hostname or IP address of the server that you are trying to connect to.
4. Press Enter.
5. You should see a message that the new key has been added to your “known_hosts” file.
6. Try to connect to the server again.

Solution 3: Check Your Computer’s Firewall Settings

Sometimes, your computer’s firewall settings may prevent you from connecting to a server. Make sure that your firewall is not blocking the SSH or SFTP ports (port 22 for SSH and port 21 for SFTP). You can also try temporarily disabling your firewall and see if it fixes the error.

Solution 4: Contact Your Server Administrator

If none of the above solutions work, you may need to contact your server administrator for help. They may be able to identify the root cause of the error and provide you with a solution.

FAQs

Q1. Why am I getting the “Server’s host key has been rejected by user” error?

A1. You may be getting the error if the server’s public key has changed, or if your computer’s “known_hosts” file has been modified or deleted.

Q2. How do I fix the “Server’s host key has been rejected by user” error?

A2. You can fix the error by removing the server’s old public key from your “known_hosts” file, adding the server’s new public key to your “known_hosts” file, checking your firewall settings, or contacting your server administrator for help.

Q3. Can I prevent the “Server’s host key has been rejected by user” error?

A3. Yes, you can prevent the error by regularly updating your computer’s “known_hosts” file and ensuring that your computer’s firewall settings allow SSH and SFTP connections.

Conclusion

We hope that this guide has helped you understand the “Server’s host key has been rejected by user” error and provided you with simple solutions to fix it. Remember to regularly update your computer’s “known_hosts” file and ensure that your firewall settings allow SSH and SFTP connections to prevent the error from occurring in the future. If you have any further questions, feel free to leave them in the comments section below!