From our troubleshooting so far, we have identified that the blog server is able to establish a connection to the database server over port
22. This connection is actually able to perform a full three-way handshake unlike our previous chapter. However, the blog server is not able to perform a three-way handshake with the database server over port
3306, the database port.
When the blog server attempts to establish a connection to the database server over port 3306, the database server is sending an ICMP destination unreachable packet back to the blog server. This packet is essentially telling the blog server that the connection attempt to the database is being rejected. Yet, the database service is ...