Two-Minute Drill

Understanding Network Fundamentals

q	Hardware addresses are defined by the data link (network interface) layer, and the IP addresses are defined by the network layer.
q	The ports are defined by the transport layer.
q	Hubs, repeaters, and NICs operate in the physical layer, switches and bridges in the data link layer, and routers in the network layer.
q	An Ethernet network based on a bus topology uses a coaxial cable as a shared cable, and a network based on star topology uses unshielded twisted-pair (UTP) cables to connect computers to a central device.
q	Computers on a Thicknet use a vampire tap to connect to the shared cable, and computers on a Thinnet use BNC connectors to connect to the shared cable.
q	Ethernet networks based on the star topology and using UTP cables are the most commonly used LANs.
q	Frames are delivered from one machine to another machine on the same network, whereas IP datagrams can be delivered across networks.
q	The netsat utility is used to view the network packets' activity (statistics) on inbound/outbound connections of your machine, whereas the ping command is used to check the reachability of another host on the network (or the Internet).
q	The snoop command is used to look into the incoming/outgoing packets on your machine (e.g., the values for the header fields).
q	The arp command is used to resolve an IP address into the corresponding hardware address.
q	The ifconfig command is used to configure a network interface (e.g., by assigning an IP address to it, bringing it up, or shutting it down). You can also use this command to obtain configuration information about an interface.

Working with Network Services

q	Solaris 10 offers Services Management Facility (SMF), which augments the traditional UNIX startup scripts and configuration files.
q	The inetadm command is used to manage the inetd-controllcd services, and svcadm is the SMF utility used to manage the network services.
q	Once you enable or disable an SMF service, the status change information goes into a configuration repository and persists across multiple boots.