Another aspect of connecting to the Internet involves how you will get the IP addresses that computers on your network will need to connect to the Internet. Many ISPs use the dynamic assignment of IP addresses to individual users and small companies. This means that your client computers receive their IP addresses from a DHCP server run by the ISP. Using dynamic addresses is fine if you have a small peer-to-peer network, but in cases where you are running your own servers on the network, you will need some static IP addresses. For example, Windows 2000 servers, NetWare servers, and Solaris servers all require static IP addresses to operate properly. Servers need a static IP address because many of the services that they provide to client computers find that service using that particular IP address.
You can lease static IP addresses directly from your ISP. Charges vary from ISP to ISP, but based on my experiences with leasing additional static IP addresses for my own small business network, I have found the cost to be around $20 to $30 per month for each static IP address.
If you work at a large company and need a large pool of IP addresses, you can go to the actual source of IP addresses, the American Registry for Internet Numbers (ARIN), to lease your addresses. ARIN is a not-for-profit organization established to register (and administer) IP addresses for North America, South America, the Caribbean, and sub-Sahara Africa.
The minimum number of addresses that can be leased from ARIN is 4,096, which costs $2,500 per year. So, unless you work for a very large company, you will have to acquire IP addresses from your ISP. For more information about ARIN, check out its Web site at http://www.arin.net/.