title: AWS - Bastion ssh tunnel to access RDS -- connecting to SSH server but not MySQL server
body: <p>I have a Bastion host set up to be able to SSH into my RDS instance. I'm using Navicat 12 to make the connection to the database, and I'm reaching the SSH server on both Navicat as well as PuTTY, but I'm not able to actually reach the RDS instance and I'm getting the following error:</p>
  
  <blockquote>
    <p>2013 - Lost connection to MySQL server at 'reading initial
    communication packet', system error: 0 "Internal error/check (Not
    system error)"</p>
  </blockquote>
  
  <p>Here are the settings I'm using to connect:</p>
  
  <pre><code>SSH settings:
  Host: my bastion public DNS
  Port: 22
  Username: ec2-user
  Authentication Method: public key
  Private key: my key path
  Passphrase: none
  
  Connection Settings:
  Endpoint: my rds endpoint
  Port: 3306
  Username: my rds username
  Password: my rds password
  (I've also tried root with no password on this to test)
  
  Security Group Info:
  Bastion-
  SSH/TCP/22/my local IP
  
  RDS-
  MYSQL/Aurora / TCP/3306/anywhere
  </code></pre>
  
  <p>If anyone can offer any sort of guidance or troubleshooting, I would super appreciate it!</p>