TCPIPNotes

TCP/IPNotes

You should assign static IP addresses to servers and let DHCP assign addresses automatically to desktop computers.

XP, W2K, and Windows 98/Me also support APIPA.

Any TCP/IP settings you configure manually on a computer will override similar settings obtained from a DHCP server.

A good practice on multihomed machines is to configure only a default gateway on the first adapter. If both adapters have gateways configured, the second gateway is used only if the first one is unavailable.

Configure multiple default gateways for a single adapter if your network topology is complex enough to allow alternate routes between subnets. This way, if a router fails, communications can still be maintained .

If your computer is configured to obtain an IP address automatically from a DHCP server but the server doesn't provide your computer with a default gateway, you either need to reconfigure the DHCP server to provide a default gateway or manually configure a TCP/IP address and subnet mask on the client in order to assign it a default gateway.

You can manually specify the IP addresses of WINS servers on your network, or you can use DHCP to assign these addresses. You can also manually enable or disable NetBIOS over TCP/IP (NetBT), obtain NetBT settings from a DHCP server, and enable or disable NetBIOS name resolution using lmhosts files using Advanced WINS. See WINS later in this chapter for more information.

If your network will be connected to the Internet, the best IP addressing scheme to follow is to assign addresses from the private IP address blocks reserved by the Internet Assigned Numbers Authority (IANA) and connect your network to the Internet using a firewall or proxy server that uses Network Address Translation (NAT). The private IP addresses reserved by IANA are shown in Table 4-52. You can use these addresses as long as you aren't directly connected to the Internet.

Table 4-52. IP address blocks reserved for private networks

Network ID	Subnet mask	Range of addresses
10.0.0.0	255.0.0.0	10.0.0.1 to 10.255.255.254
172.16.0.0	255.240.0.0	172.16.0.1 to 172.31.255.254
192.168.0.0	255.255.0.0	192.168.0.1 to 192.168.255.254

Table 4-52. IP address blocks reserved for private networks

See Also