Software components for TCP/IP networking

To use TCP/IP, you need the following software components:

Figure 1. Components of TCP/IP in Neutrino.
Manager that provides support for dynamically loaded networking modules. It includes a fully featured TCP/IP stack derived from the NetBSD code base.
devn-*, devnp-*
Managers that form an interface with the hardware.

To set configuration parameters, use the ifconfig and route utilities, as described below.

If you're using the Dynamic Host Configuration Protocol (DHCP), you can use dhcp.client to set the configuration parameters for you as provided by the DHCP server.

Note: The device enumerator starts io-pkt* automatically when you boot, loads the TCP/IP stack, and starts the appropriate drivers for the detected devices. If you want to specify any options (e.g., to enable IPSec) when you boot, you need to edit the device-enumeration files. For more information and an example, see "Device enumeration" in the Controlling How Neutrino Starts chapter in this guide.

The TCP/IP stack is based on the NetBSD TCP/IP stack, and it supports similar features. To configure the stack, use the ifconfig and route utilities as described below.

To configure an interface with an IP address, you must use the ifconfig utility. To configure your network interface with an IP address of, you would use the following command:

ifconfig if_name

where if_name is the interface name that the driver uses.

If you also want to specify your gateway, use the route command:

route add default

This configures the gateway host as

If you then want to view your network configuration, use the netstat command (netstat -in displays information about the network interfaces):

Name Mtu    Network   Address           Ipkts Ierrs Opkts Oerrs Coll
lo0  32976  <Link>                       0    0     0     0     0
lo0  32976  127          0    0     0     0     0
en0  1500   <Link>    00:50:da:c8:61:92 21    0     2     0     0
en0  1500   10        21    0     2     0     0

To display information about the routing table, use netstat -rn; the resulting display looks like this:

Routing tables

Destination Gateway    Flags Refs Use Mtu Interface
default   UGS   0    0   -   en0
10 U     1    0   -   en0 UH    0    0   -   lo0  UH    0    0   -   lo0

The table shows that the default route to the gateway was configured (