A TCP/IP network uses individual IP addresses for each network member. These IP addresses may be assigned manually or automatically. Assigning hostnames to the network members makes the TCP/IP network more convenient for users, since they do not have to remember the numerical IP addresses. A local hosts file or a DNS server provide hostname resolution. If destinations outside the local network segment should be reached, a gateway is used to route the packets to and from other network segments. The subnet mask determines which IP addresses belong to the local network segment, and which addresses are outside. Finally, a DHCP server greatly simplifies network maintenance: A DHCP server administrates a local network segment and assigns IP addresses to the network clients. Also provided are gateway, subnet mask, and DNS server settings. (A DHCP based network always uses symbolic hostnames).

Since local network traffic should be shielded from the outside world, some IP address ranges are reserved for local networking and are not routed to the outside, e.g. the Internet. The IANA (Internet Assigned Numbers Authority) has reserved three IP address ranges for use in local (private) internets (RFC 1918) :

10.xxx.xxx.xxx, 172.16.xxx.xxx, 192.168.xxx.xxx.

Addresses in this range can be used without coordination with the IANA and are the most likely IP address ranges used in any company network.

To further partition a network, e.g. into multiple divisions which are interconnected via routers and gateways, a subnet mask is used. The subnet mask for a class C network (max. 255 members) is 255.255.255.0, but smaller subnets may be used too. The TCP/IP software logically ANDs an IP address with the subnet mask to determine if the destination is within the local network subnet, or if the traffic must be routed via a gateway. A DHCP-administrated network will automatically provide the required settings. If your IP network uses manually assigned addresses, ask your network administrator for a valid IP address and subnet mask.

Three initialization steps are required to initialize the hardware and the TCP/IP software stack.

Device specific settings: netconfig.c - Settings for IP address, DNS and DHCP, network mode
Hardware Initialization: DM2_EmacInit() - configure DSP memory interface, initialize EMAC.
Software Initialization: net_init() - initialize TCP/IP stack, use settings from netconfig.c

Refer to chapter Initialization Modules for more details