go start then run then type cmd
in the window that pops up type ipconfig
this will show the default gateway and the subnet mask
assuming you are using a class c network with a subnet mask of 255.255.255.0 then the only thing that should be different from your ip to the default gateway is the last number which will range from 2-254 if you want more detail about the address type ipconfig /all and shows all the info

If your computer automatically obtained IP address from the LAN once you connect it, this will surely come from the DHCP server. Most often, DHCP server also act as the gateway to the Internet. To know your IP address, gateway and DNS, here’s how (specific steps):

From “Start” button, click “Run” then type “cmd” or “command” (in WindowsXP). This will come the DOS Command prompt window. From that window, type “ipconfig /all”. This will show all of your network configuration. =)

In order to confirm your ip and DNS address , u can contact to your internet service provider (i.e your local ISP)

Usually you configure you pc to obtain IP address and DNS automatically. This means that when you boot up the pc requests and is given the information from a LAN DHCP server (which can be the router, or the server, or a mixture of the two, depending upon the LAN itself).

Seldomly and only for good reason, do you configure your pc to use a static LAN IP address and static DNS address because this is more and often needless work.

There is no Administrator IP address; there is a default gateway IP address and a DNS IP address.