Chapter 10 Flashcards
1000BaseT
Ethernet over UTP cables, using hubs to produce a star topology; supports a maximum (theoretical) transmission of 1Gbit/s.
100BaseT
Ethernet over UTP cables, using hubs to produce a star topology; supports a maximum (theoretical) transmission of 100 Mbit/s.
10BaseT
Ethernet over UTP cables, using hubs to produce a star topology; supports a maximum (theoretical) transmission of 10 Mbit/s.
Address Resolution Protocol
A protocol used to learn a network hardware address based on an IPv4 address. See Neighbor Discovery Protocol (NDP).
ARP
A protocol used to learn a network hardware address based on an IPv4 address. See Neighbor Discovery Protocol (NDP).
Broadband
High-speed (greater than 200Kbps) Internet connections delivered to homes and small businesses.
Networking technologies that support simultaneous transmission of data, voice, and video.
Broadcast
A type of network communication in which one computer sends a message to many computers (typically all the computers on the sender’s local network segment).
CIDR
A method of breaking IP addresses into subnets for routing purposes that doesn’t rely on the traditional Class A/B/C distinctions. CIDR is more flexible than the class system but requires certain Internet routers to have larger routing tables.
Classless Inter-Domain Routing (CIDR)
A method of breaking IP addresses into subnets for routing purposes that doesn’t rely on the traditional Class A/B/C distinctions. CIDR is more flexible than the class system but requires certain Internet routers to have larger routing tables.
Default route
The route that network packets take if a more specific route doesn’t direct them in some other way. The default route typically involves a gateway or router system that can further redirect the packets.
DHCP
Provides for automatic downloading of IP address and other configuration data from a server to a client. Allows for reuse of IP addresses so that the number of hosts can exceed the number of available IP addresses. See BOOTP.
DHCP lease
A temporary assignment of an IP address to a DHCP client by a DHCP server. Clients must periodically renew their DHCP leases or risk losing the right to use the address.
Digital Subscriber Line (DSL)
A type of broadband network access provided over telephone lines. Several subtypes of DSL exist, including Asymmetric DSL (ADSL) and Symmetric DSL (SDSL).
DNS
The Domain Name System (DNS) is a distributed database of computers that converts between IP addresses and hostnames.
Domain name
A name assigned to a group of computers, such as example.com. Individual computers have hostnames that include the domain name, such as jupiter.example.com.
Dotted quad
A method of referring to an IPv4 address or netmask that uses four 1-byte numbers separated by dots (.), as in 192.168.72.27 or 255.255.255.0.
DSL
A type of broadband network access provided over telephone lines. Several subtypes of DSL exist, including Asymmetric DSL (ADSL) and Symmetric DSL (SDSL).
Frame
In networking, a data packet associated with network hardware (such as Ethernet) as opposed to the software (such as TCP/IP).
Gigabit Ethernet
A variety of Ethernet that can transfer 1,000 megabits (1 gigabit) per second.
Half-duplex
A type of data transmission in which data can be sent in only one direction at a time.
Hardware Address
A code that uniquely identifies a single network interface. This address is built into the device itself rather than assigned in Linux.
Host
This program serves as a replacement for the simpler uses of nslookup, but it lacks an interactive mode, and of course many details of its operation.
Hostname
A computer’s human-readable name, such as persephone.example.com.
Hub
Hub
A type of network hardware that serves as a central exchange point in a network. Each computer has a cable that links to the hub, so all data pass through the hub. Hubs echo all data they receive to all the other computers to which they connect. See also switch.
A USB device that can be used to multiply the available connectors; the USB hub plugs into a computer’s USB port, and multiple devices can plug into the USB hub.
ICMP
A type of network packet that’s commonly used to signal error conditions, such as corrupted packets.
Internet Control Message Protocol (ICMP)
A type of network packet that’s commonly used to signal error conditions, such as corrupted packets.
Internet Protocol (IP)
An internet-layer protocol that’s an important part of the TCP/IP network stack because it handles data packet exchange based on low-level addressing.
IP
An internet-layer protocol that’s an important part of the TCP/IP network stack because it handles data packet exchange based on low-level addressing.
IP address
A computer’s numeric TCP/IP address, such as 192.168.45.203.
IP masquerading
A technique in which a router can “hide” a whole network from view, making all the systems look like one computer to the outside world.
IPv6
The “next-generation” Internet Protocol. This upgrade to TCP/IP allows for a theoretical maximum of approximately 3.4 _ 1038 addresses, as opposed to the 4 billion addresses possible with the older IPv4. Although IPv4 addresses are still available in many regions in late 2012, future growth of the Internet will depend upon IPv6.
Localhost
A name for the local computer.
Loopback address
A name that refers to a network interface or address that points back to the computer itself. This is typically the 127.0.0.1 IP address.
MAC address
A low-level address associated with a piece of network hardware. The MAC address is usually stored on the hardware itself, and it’s used for local network addressing only. Addressing between networks (such as on the Internet) uses higher-level addresses, such as an IP address.
Machine name
The portion of a hostname that identifies a computer on a network, as opposed to the network as a whole (for instance, ginkgo is the machine name portion of ginkgo.example.com). The machine name is sometimes used in reference to the entire hostname.
Media Access Control (MAC) address
A low-level address associated with a piece of network hardware. The MAC address is usually stored on the hardware itself, and it’s used for local network addressing only. Addressing between networks (such as on the Internet) uses higher-level addresses, such as an IP address.
Multicast
A method of sending network data to multiple remote sites. Multicasts differ from broadcasts in that multicasts are more focused, whereas broadcasts are typically sent to all the computers on a network.
NAT
A technique in which a router can “hide” a whole network from view, making all the systems look like one computer to the outside world.
NDP
A protocol used to learn a network hardware address based on an IPv6 address. See also Address Resolution Protocol (ARP).
Neighbor Discovery Protocol (NDP)
A protocol used to learn a network hardware address based on an IPv6 address. See also Address Resolution Protocol (ARP).
Netmask
network mask: the network part of an IP address; See variable length subnet mask
Network
An interconnected set of hosts and other network devices which share a common physical layer such as Ethernet, X.25, etc.;See LAN and WAN.
Network Address Translation (NAT)
A technique in which a router can “hide” a whole network from view, making all the systems look like one computer to the outside world.
Network stack
A collection of drivers, kernel procedures, and other software that implements a standard means of communicating across a network. Two computers must support compatible protocol stacks to communicate. The most popular protocol stack today is TCP/IP. Also called a network stack.
NFS
A protocol (developed by Sun Microsystems) enabling a UN*X machine to mount a remote disk area as part of its local filesystem; widely considered of questionable security.
Packet
A limited amount of data collected together with addressing information and sent over a network.
Packet sniffer
A program that monitors network traffic at a low level, enabling diagnosis of problems and capturing data. Packet sniffers can be used both for legitimate network diagnosis and for data theft.
Point to Point protocol (PPP)
A method of initiating a TCP/IP connection between two computers over an RS-232 serial line or modem. See also PPP over Ethernet (PPPoE).
Port
A number that identifies the program from which a data packet comes or to which it’s addressed. When a program initiates a network connection, it associates itself with one or more ports, enabling other computers to uniquely address the program.
Port Number
A number that identifies the program from which a data packet comes or to which it’s addressed. When a program initiates a network connection, it associates itself with one or more ports, enabling other computers to uniquely address the program.
PPP
A method of initiating a TCP/IP connection between two computers over an RS-232 serial line or modem. See also PPP over Ethernet (PPPoE).
PPP over Ethernet (PPPoE)
A variant of the Point-to-Point Protocol (PPP) that’s optimized for use over Ethernet rather than RS-232 serial connections. PPPoE is used by some DSL providers.
PPPoE
A variant of the Point-to-Point Protocol (PPP) that’s optimized for use over Ethernet rather than RS-232 serial connections. PPPoE is used by some DSL providers.
Privileged Port
A port (see port number) that’s numbered less than 1024. Linux restricts access to such ports to root. In networking’s early days, any program running on a privileged port could be considered trustworthy because only programs configured by professional system administrators could be run on such ports. Today, that’s no longer the case. See also unprivileged port.
Protocol stack
A collection of drivers, kernel procedures, and other software that implements a standard means of communicating across a network. Two computers must support compatible protocol stacks to communicate. The most popular protocol stack today is TCP/IP. Also called a network stack.
Reverse lookup
A DNS lookup that uses an IP address as a key and that returns a hostname.
SLAAC
Allows an IPv6 computer to determine its network address automatically by examining traffic on the network.
Subdomain
A subdivision of a domain. A subdomain may contain computers, subdomains of its own, or both.
Subnet mask
network mask: the network part of an IP address; See variable length subnet mask.
Switch
In computer networks, a dedicated hardware used to connect devices and quickly shunt packets through the network.
TCP
A connection-oriented transport protocol. Connection-oriented transport protocols provide reliable transport, in that if a segment is dropped, the sender can detect that drop and retransmit that dropped segment. Specifically, a receiver acknowledges segments that it receives. Based on those acknowledgments, a sender can determine which segments were successfully received.
TCP/IP
The protocol suite developed by the Department of Defense (DoD) in conjunction with the Internet. It was designed as an internetworking protocol suite that could route information around network failures. Today it’s the de facto standard for communications on the Internet.
Transmission Control Protocol (TCP)
A major transport-layer protocol type in modern networking. TCP supports error correction and other features that are helpful in maintaining a link between two computers.
TRansmission Control Protocol/Internet Protocol (TCP/IP)
The most important protocol stack in common use today, and the basis for the Internet.
Twisted-pair
A type of wiring in which pairs of wires are wrapped around each other (and typically enclosed in a plastic sheath). Twisted-pair cabling is commonly used for Ethernet and certain other network cabling. Many telephone wires also use twisted-pair cabling.
UDP
A transport-layer protocol used on the TCP/IP stack. UDP is a simple and efficient protocol, but it lacks error checking and other advanced features that can be helpful in maintaining a connection.
Unprivileged Port
A port that’s numbered from 1024. Such ports may be accessed by any user and so are commonly used by client programs and by a few servers that may legitimately be run by ordinary users. See also privileged port.
User Datagram Protocol (UDP)
A transport-layer protocol used on the TCP/IP stack. UDP is a simple and efficient protocol, but it lacks error checking and other advanced features that can be helpful in maintaining a connection.
