I in order to be on a computer network connection between a host on the SQL database to read and write operations, apply for a free peanut shells in the dynamic domain name, and the host computer through a router Settings as follows:

The IP and MAC binding Settings: IP address and host computer 192.168.0.198 binding
Virtual server Settings: set the IP address 192.168.0.198 external ports and internal ports are: 1433
DDNS Settings: peanut shells domain show log in successfully,

Through to the above Settings, the host computer router can net out any computer connected to the host computer through peanut shells domain name on the SQL database, (don't need to be installed on the host computer peanut shells, client)
I want to bring the question now is:
(1) the telecom sector to network must be provided by the host computer is public, private network cannot use shell domain name, can use in private network conditions by setting the peanut shells domain name?
(2) in the telecom sector to provide public, under the condition of the recent local telecommunication service providers unity with the new router, set up the way of the Internet by the original "use broadband account and password" to "obtain an IP address automatically" unified regulation, the result by peanut shells unable to connect to host computer database, dynamic domain name for some reason? Does a router set way of the Internet to "obtain an IP address automatically", access is not a public, but the private network? Is it must set the router's Internet connection to use broadband account and password, can use the peanut shell dynamic DNS from the network to connect the computer database?
The above question, please expert advice, be obliged!