Glossary

A (Address) Resource Record

Resource record used in the Domain Name System (DNS) zone file to map IPv4 addresses to hostnames, like the entries in the /etc/inet/ hosts file.

AAAA (Address) Resource Record

Resource record used in the Domain Name System (DNS) zone file to map IPv6 addresses to hostnames ”similar in functionality to the local /etc/inet/ipnodes file.

Address Resolution Protocol ( ARP )

A protocol in the TCP/IP model that operates between the network interface and Internet layers . It is used to map a 32-bit IP address to a 48-bit Ethernet or MAC address.

anycast address

An IPv6 address type, similar to a multicast address, where a message is sent to a specific group of hosts on a network. A message sent to an anycast address is received only by the nearest host that is a member of the group.

bandwidth

The maximum capacity at which data can be transferred across a communication medium.

baseband

Communication uses the entire bandwidth of the medium exclusively. An error (collision) occurs if there is more than one signal present.

Berkeley Software Distribution ( BSD )

A variant of Unix developed at the University of California at Berkeley. Solaris contains some historical links to files for BSD compatibility. Prior to Solaris 2.0, SunOS was based on the BSD variant of Unix.

broadband

Multiple signals existing concurrently on the same communication media, allowing more information to be transmitted in a given time.

broadcast address

The IP address used to send a message to all computers connected to a network.

client

A networked computer that makes use of services provided by a server .

Common Desktop Environment ( CDE )

The standard graphical user interface (GUI) supplied with the Solaris 9 operating environment.

Company Identifier ( CID )

The first (leftmost) 24 bits of an Ethernet address that are assigned to a company, or organization, by the Institute of Electronic and Electrical Engineers (IEEE). The CID is used with a vendor identifier (VID) to form an Ethernet address . The CID is also known as an organizationally unique identifier (OUI).

connection-oriented protocol

A protocol that establishes a virtual connection prior to any data transmission taking place. The Transmission Control Protocol (TCP) is an example of a connection-oriented protocol.

connectionless protocol

A protocol that does not establish any connection prior to data transmission taking place. The User Datagram Protocol (UDP) is an example of a connectionless protocol.

DHCP lease time

The time that an IP address being managed by DHCP is valid. At the end of the lease time, the lease expires and is no longer available to the DHCP client unless it is renewed.

DHCP scope

The range of IP addresses being managed by a DHCP server.

diskless client

A computer connected to a network that does not have any local storage capability and retrieves its network configuration information from a remote server on the network. All file systems and swap space reside on remote file servers.

DNS primary name server

The master server for a DNS domain. Changes and updates to the data held in the DNS domain are made on this server. A serial number that is incremented on the primary server is used by secondary DNS servers to detect updates and synchronize the data files. The Solaris versions of DNS have a single primary DNS server per domain.

DNS secondary name server

A slave server for a DNS domain. There can be multiple secondary name servers in a DNS domain and they act as a backup for the primary name server. A secondary name server is synchronized at regular intervals through zone transfers from the primary name server.

Domain Name System ( DNS )

A service providing domain name “to “IP address resolution, and vice versa, primarily on the Internet.

Dynamic Host Configuration Protocol ( DHCP )

A protocol used to automatically provide IP address and other network configuration information to clients .

encapsulation

The process of adding protocol header information to the data packet at each layer of the TCP/IP model before the packet is passed to the next layer. Each layer's header information is interpreted only by its peer layer at the destination; the other layers handle this information as part of the data.

Ethernet address

A 48-bit unique address that identifies a network interface. The address comprises a company identifier (CID) and a vendor identifier (VID). It is also known as a MAC address and is hard-coded by the manufacturer.

Ethernet frame

The basic unit of transfer on Ethernet networks, comprising the sender address, the destination address, control information, and the actual data to be transferred.

Fully Qualified Domain Name ( FQDN )

The absolute path to a domain, such as www.sun.com.

Fully Qualified Host Name ( FQHN )

The absolute path to a hostname, which includes the short hostname itself, as well as the domain name in which it resides, such as sales.sun.com.

Hop count

A means of measuring distance between two hosts on a network, used in network routing. It identifies the number of routers, or hosts, that a data packet passes through to reach its destination. Each router, or host, constitutes a hop.

host

A computer, or other device, that is connected to a network.

Internet Control Message Protocol ( ICMP )

An integral part of the Internet Protocol (IP) that is used to send error and control messages to other hosts on the network. It is often used in network problem diagnosis. The ping command uses ICMP to send ECHO REQUEST messages.

Internet Engineering Task Force ( IETF )

The body that defines standards for protocols. The standards are released as Requests For Comments (RFCs).

Internet Protocol ( IP )

Part of the TCP/IP suite that is responsible for the delivery of datagrams across a network and any fragmentation/reassembly of data required.

IP forwarding

The process of forwarding IP datagrams from one network to another. This is only enabled on routers, or systems acting as routers.

IPng

Synonymous with IPv6 , ng stands for next generation.

IPv4 address

A 32-bit address that uniquely identifies a host on a network.

IPv6

The next version of the Internet Protocol that is being introduced to alleviate the shortfall in IPv4 addresses. IPv6 uses 128-bit IP addresses, providing a vast increase in the number of available addresses. It is also a classless protocol, unlike IPv4.

IPv6-over-IPv4 Tunnel

The feature that enables IPv6 hosts to communicate across an IPv4 network. It was introduced to assist with the transition from IPv4 to IPv6 so that both protocols can co-exist on the same network infrastructure.

JumpStart client

A computer connected to a network that makes use of the Solaris JumpStart feature to automatically install the Solaris operating environment over a network.

JumpStart install server

A server that provides the installation image for a JumpStart client to install the Solaris operating environment automatically over a network.

JumpStart profile server

A server that provides the configuration information for a JumpStart client to install the Solaris operating environment automatically over a network. Also known as a JumpStart configuration server.

local area network ( LAN )

A network that spans a small geographical area, normally a site, but can comprise numerous buildings . A LAN is used to interconnect a number of departments in an organization, or a number of systems. A LAN uses private cabling and achieves a high data transmission rate. LAN hardware is much cheaper and easier to install than a Wide Area Network (WAN) . Ethernet is an example of a LAN technology.

MAC Address

Synonymous with Ethernet address .

Master DNS Server

Synonymous with primary name server .

Multicast Address

An IP address that is used to communicate with a specific group of hosts on a network. Messages sent to multicast addresses are received only by hosts belonging to the multicast group.

MX (Mail Exchanger) Resource Record

Resource record used in the Domain Name System (DNS) zone file to identify mail servers to be used for handling electronic mail. A preference value can also be applied to this record to specify a master and slave server.

name server switch

The common name for the switch file /etc/nsswitch.conf , which is used to determine the search order and the name service to use to obtain network information.

network mask

A value that is used to distinguish the network portion of an IP address from the host portion.

network topology

The physical structure of a network ”how the hosts, or nodes, on a network are physically wired together.

node

Synonymous with host .

NS (Name Server) resource record

Resource record used in the Domain Name System (DNS) zone file to identify other DNS name servers in a domain. This record is also used to show where a sub-domain has been delegated to another DNS server.

Open Shortest Path First ( OSPF )

A link-state routing protocol that maintains a complex knowledge of the network topology. When a network change occurs, only the change is exchanged with other routers, unlike RIP , where the entire routing table is exchanged. OSPF can process updates to the network configuration more quickly than RIP.

protocol

The defined set of rules that govern how data is transferred between hosts on a network.

PTR (Pointer) Resource Record

Resource record used in the Domain Name System (DNS) zone file for mapping hostnames to IPv4 addresses and for reverse DNS lookups.

reliable protocol

Each exchange of data is acknowledged by the receiving host. The sender knows whether each transmission was successful because of this acknowledgement and resends any data that was not acknowledged. TCP is an example of a reliable protocol.

Reverse Address Resolution Protocol ( RARP )

A protocol in the TCP/IP model that operates between the Network Interface and Internet layers. It is used to map a 48-bit Ethernet address to a 32-bit IP address.

Routing Information Protocol ( RIP )

A distance-vector routing protocol that determines the path to the destination by the number of hops taken. The entire routing table is passed to the router's neighbor at regular intervals and when a change occurs. The maximum number of hops allowed in a path is 15. If the hop count reaches 16 (deemed to be infinity), the destination is marked as unreachable.

server

A computer system that provides services to other systems on a network.

SOA (Start Of Authority) resource record

Resource record used in the Domain Name System (DNS) zone file to identify the start of the zone data and to define default parameters for the whole zone.

stateful protocol

Both the sending and receiving hosts monitor a connection and exchange status information as part of the data exchange, providing greater reliability, but, because of the extra information, a greater overhead. TCP is an example of a stateful protocol.

stateless protocol

Neither the sending nor receiving hosts monitor the state of a communications link and both operate independently of the other, unlike stateful protocols where there is a clear exchange of control information. Stateless protocols are inherently less reliable than stateful protocols because data packets can be lost, or arrive in any order, but they incur virtually no overhead. Connectionless protocols are also normally stateless. UDP is an example of a stateless protocol.

System V

The variant of Unix developed by AT&T Bell Labs. Solaris is based on System V Unix Release 4.

TCP/IP model

A protocol stack that enables devices to communicate across a network. The TCP/IP model is a four-layer model comprising the Network Interface (including hardware layer), Internet, Transport, and Application layers. The structure is hierarchical, with each layer performing a specific function.

Transmission Control Protocol ( TCP )

A connection-oriented, reliable, and stateful protocol that operates at the Transport layer of the TCP/IP model. It is used on networks where a guaranteed delivery service is required. TCP implements a guaranteed delivery service through the use of acknowledgements and error checking/retransmission mechanisms.

unicast address

An IP address used to communicate with a single host on a network.

unreliable protocol

Each exchange of data is not acknowledged, so packets can be lost. Applications using an unreliable protocol normally handle data loss within the application and do not rely on the network. UDP is an example of an unreliable protocol.

User Datagram Protocol ( UDP )

A connectionless, unreliable, and stateless protocol that operates at the Transport layer of the TCP/IP model. It was designed for applications that do not require a reliable transport mechanism, primarily because the application itself carries out any error checking and data delivery guarantee.

vendor identifier ( VID )

The second (rightmost) 24 bits of an Ethernet address that are assigned and managed by the vendor and must be unique within the vendor organization. The VID is used with the company identifier (CID) to form an Ethernet address.

wide area network ( WAN )

A network that spans a large geographical area and that can be used to interconnect departmental local area networks (LANs), or different locations in a city or state. A WAN makes use of third-party service providers and telecommunications companies to provide the interconnection. Data transfer rates are typically slower than that achieved on a LAN. Frame relay is an example of a WAN technology.

zone

The extent of the authority of a DNS name server.

zone file

A data file used in the domain name system (DNS) relevant to a particular zone . The file identifies configuration information and hostname resolution details for domains and systems that come under the authority of the zone.

zone transfer

The process by which secondary DNS name servers are updated from the primary DNS server to synchronize the data.