Bay Networks 5390, Administering, Page: 784 / 888

C5-2 893-741-B
Network Protocols
When one station wants to transmit data, it listens for traffic on the medium. If there is none, the
station transmits the data. If there is traffic, the station waits until the transmission has completed.
If two stations transmit simultaneously, both stop transmitting and then each waits a different length
of time to retransmit.
Ethernet Addresses
Each Ethernet interface has a unique address. To maintain uniqueness, Ethernet addresses are
managed by the IEEE, which assigns blocks of addresses to manufacturers of LAN devices. Each
manufacturer assigns a unique address to each device built. An Ethernet address consists of six
octets of hexadecimal digits, for example: 00-08-2D-00-00-37.
The Model 5390 Ethernet address is assigned at the factory; it is permanently stored in ROM. You
can display this address using either the ROM Monitor or the CLI stats command. Sometimes,
Ethernet addresses are used for testing the local area network.
TCP/IP Protocols
TCP/IP is a set of protocols that are part of the Internet Protocol suite. These protocols define the
network and transport layer. The Model 5390 server also implements some protocols at the
application layer. The Internet Protocol suite evolved from work sponsored by the Defense Advanced
Research Projects Agency (DARPA) for the development of a wide area network to interconnect
multiple networks and hosts. The end result of this work became the DARPA Internet, a wide area
network that ranges from networks with a small number of hosts to networks with a large number
of hosts to networks interconnected with other networks. These interconnections constitute an
Internet.
• The Model 5390 server supports the latest enhancements provided in the 4.3BSD Tahoe
distribution of UNIX. These include enhancements, such as subnet mask and broadcast
addresses, required by changes in the Internet protocols after the release of 4.2BSD.