Unable to get any type of connection using MySQL on LAN
Are you using Putty to log in to DB server or some other server?

If its DB server then, error can be caused by following  


Incorrect username/password  
Incorrect port number  
MySQL DB is not up and running  


If you are trying from different host to connect as in remote DB host make sure  


you have connectivity between the hosts and  
there is no IP based restrictions. As you know admin can restrict access to certain IP address.  


Hope this helped.