{"id":2097,"date":"2024-03-19T15:05:07","date_gmt":"2024-03-19T14:05:07","guid":{"rendered":"https:\/\/hoganhost.com.ng\/blog\/?p=2097"},"modified":"2024-08-12T13:20:16","modified_gmt":"2024-08-12T12:20:16","slug":"how-to-fix-the-warning-remote-host-identification-has-changed-error","status":"publish","type":"post","link":"https:\/\/hoganhost.com.ng\/blog\/tech-tips-tools\/how-to-fix-the-warning-remote-host-identification-has-changed-error\/","title":{"rendered":"How To Fix the \u201cWarning: Remote Host Identification Has Changed\u201d Error"},"content":{"rendered":"

A secure internet connection is not just the ideal \u2014 it\u2019s essential. In fact, we\u2019re going to go as far as saying it\u2019s the number one priority for your website. The \u201cWarning: Remote host identification has changed\u201d error protects your connection from certain malicious attacks, although in some cases, you can inadvertently cause the error too.<\/p>\n

The error is related to your\u00a0Secure Shell (SSH) keys\u00a0and the server \u201cfingerprint\u201d a client will check for. If Secure Shell thinks there\u2019s an issue, it will block access to your server and throw an error. But you can fix this in a few steps.<\/p>\n

Over the next few minutes, we\u2019re going to show you how to fix the \u201cWarning: Remote host identification has changed\u201d error for both Windows and Mac. First, though, let\u2019s give you some more details on the error message itself.<\/p>\n

What the \u201cWarning: Remote Host Identification Has Changed\u201d Error Is<\/h2>\n

One of the most secure ways to connect to a web server is to\u00a0use SSH. It\u2019s a command-line tool that lets you access an insecure network securely. Consider it like a \u201csuper-SFTP\u201d type of setup, although it\u2019s not a 1:1 comparison in practice.<\/p>\n

You can access your site from almost anywhere you can use the internet, as long as you have the right login credentials. What\u2019s more, most macOS and Linux machines have an SSH client built into the Operating System (OS). For Windows, you\u2019ll use a dedicated interface (and we\u2019ll talk about this in more detail later).<\/p>\n

As for the \u201cWarning: Remote host identification has changed\u201d error, it relates to the security checks your client will do. An SSH connection uses dedicated \u201ckeys\u201d \u2014 small files stored on your computer \u2014 as authentication. It\u2019s sort of like a\u00a0Secure Sockets Layers (SSL) handshake, and in fact, there are some high-level\u00a0similarities between SSH and SSL.<\/p>\n

One aspect the keys help with is to provide a permanent fingerprint of its host server. This will make sure the connection is accurate and that you\u2019re not subject to a\u00a0\u201cmachine-in-the-middle\u201d attack.<\/p>\n

If the client thinks those fingerprints differ from what it understands to be correct, you\u2019ll get the \u201cWarning: Remote host identification has changed\u201d error at the point of login:<\/p>\n

[<\/span>user@hostname ~]<\/span>$ ssh<\/span> root@user\r\n\r\n@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\r\n\r\n@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!<\/span> @\r\n\r\n@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\r\n\r\nIT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!<\/span>\r\n\r\nSomeone could be eavesdropping on you right now (<\/span>man-in-the-middle attack)<\/span>!<\/span>\r\n\r\nIt is also possible that a host<\/span> key has just been changed.\r\n\r\nThe fingerprint for<\/span> the RSA key sent by the remote host<\/span> is\r\n\r\nxx:xx:xx.\r\n\r\nPlease contact your system administrator.\r\n\r\nAdd correct host<\/span> key in<\/span> \/home\/hostname \/.ssh\/known_hosts to get rid of this message.\r\n\r\nOffending RSA key in<\/span> \/var\/lib\/sss\/pubconf\/known_hosts:4\r\n\r\nRSA host<\/span> key for<\/span> user has changed and you have requested strict checking.\r\n\r\nHost key verification failed.<\/code><\/pre>\n
As errors go, this is detailed and clear \u2014 it tells you what\u2019s happened, a potential reason for why, and how you might fix it.<\/p>\n
However, there\u2019s one aspect we can touch on a little further before showing you how to fix the \u201cWarning: Remote host identification has changed\u201d error.<\/p>\n
How the known_hosts File Helps SSH Authentication<\/h3>\n
You\u2019ll notice that the error message references a\u00a0known_hosts file. The name should give you a clue as to what it contains, but for clarity, it\u2019s a list of SSH remote hosts known to the computer. It\u2019s used as a reference client file for the authentication process.<\/p>\n
When you first connect to a server, you\u2019ll often get a confirmation request through your interface, asking whether you want to connect. If so, this fingerprint will become part of your\u00a0known_hosts<\/strong>\u00a0file.<\/p>\n
Of course, if the fingerprint differs from what is in the\u00a0known_hosts<\/strong>\u00a0file, this could indicate a malicious user is targeting you. In other cases, you may already know why there\u2019s a difference, although it pays to be vigilant regardless.<\/p>\n