TraceExample

How do I use "Why Can't I Connect?"

What is this trace telling me?

TCP/IP sockets are asynchronous so there is no way to lay out a simple set of rules. The following is a common sequence of events you would expect to see while connecting to a server.

Here is an example of a successful connection to a MySQL server and the steps used.

Wed Sep 4 10:45:11 2013
The host name I found is: ChrisLinux3
Try to find the local machine name.

Wed Sep 4 10:45:11 2013
Checking address: 192.168.1.72
Check for a usable IP address. (local host excluded: 127.xxx.xxx.xxx)

Wed Sep 4 10:45:11 2013
A bindable address found: 192.168.1.72
A usable IP address has been found. If this fails, the network connection on the local machine has failed.

Wed Sep 4 10:45:11 2013
Bind, socket handle: 10
** 192.168.1.72 Port: 56811**
Bind the socket handle to a system assigned port. Now it can be used to connect.

Wed Sep 4 10:45:11 2013
Receive timeout set to: 60 seconds

Wed Sep 4 10:45:11 2013
Send timeout set to: 60 seconds

Wed Sep 4 10:45:11 2013
chrislinux
** Address found: 192.168.1.68**
Resolve the server name to an IP address. If this fails, DNS is down, the server can't be seen from your machine, or the server is not in your host file.

Wed Sep 4 10:45:11 2013
Connect, socket handle: 10 Port: 56811
** 192.168.1.68 Port: 3306
** Send buffer size: 23400
** Receive buffer size: 87380**
The connection is successful. If this fails, the port is probably blocked by a firewall or the service is not available.

Wed Sep 4 10:45:11 2013
Receive, socket handle: 10 Port: 56811
** From: 192.168.1.68 Port: 3306
** Message length: 95
** 5B 00 00 00 0A 35 2E 35 2E 33 32 2D 30 75 62 75 [....5.5.32-0ubu
** 6E 74 75 30 2E 31 33 2E 30 34 2E 31 00 30 00 00 ntu0.13.04.1.0..
** 00 6E 71 6C 48 63 3A 36 3F 00 FF F7 08 02 00 0F .nqlHc:6?.......
** 80 15 00 00 00 00 00 00 00 00 00 00 7A 6A 24 72 ............zj$r
** 37 55 28 66 4A 21 61 48 00 6D 79 73 71 6C 5F 6E 7U(fJ!aH.mysql_n
** 61 74 69 76 65 5F 70 61 73 73 77 6F 72 64 00 ative_password.
An opening message from the server. Everything looks OK.

Wed Sep 4 10:45:11 2013
Close, socket handle 10
We're done, close the connection.

All the possible trace messages