This is a common issue when connecting to a remote server via SSH. It usually happens when the remote host's SSH key has changed—either due to a system reinstall, key regeneration, or IP reassignment. Here's how to resolve it safely.
🧠 Why This Happens
When you SSH into a server, your system checks the server’s identity using its stored SSH key. If the key has changed, SSH warns you about a potential man-in-the-middle attack. While this can be a real security concern, it's often benign—especially if you know the server was reconfigured.
🛠️ Step-by-Step Fix
1. Attempt SSH Connection
ssh root@10.0.2.37
You’ll see a warning like:
WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!
Offending ECDSA key in /home/jpudasaini/.ssh/known_hosts:17
2. Remove the Old Host Key
- Use ssh-keygen to remove the outdated key:
ssh-keygen -R 10.0.2.37
- Alternatively, manually delete the line from known_hosts:
sed -i '17d' ~/.ssh/known_hosts
Or open the file with a text editor:
sudo vi ~/.ssh/known_hosts
Then delete line 17.
3. Reconnect and Accept the New Key
- Retry your SSH connection:
ssh root@10.0.2.37
- You’ll be prompted to accept the new key. Type yes and proceed.
✅ You're Back In!
Once the new key is accepted, your SSH connection should work as expected.
