CCNA Vocabulary_H_I_J.txt

• communication that only allows one station to receive while the other station is transmitting
• hierarchical addressing an addressing scheme in which a network is partitioned into sections, with the section identifier forming one part of each destination's address and the destination identifier forming another

the portion of a binary number that carries the most weight, the one written farthest to the left. High-order bits are the 1s in the network mask.

the passage of a data packet between two network nodes.

a network device that has an IPv4 address assigned to it to communication over a network.

IPv4 address of a network host. When talking about host addresses, they are the network layer addresses.

a group defined by a class D address (multicast, ranging from 224.0.0.0 to 239.255.255.255), whereupon hosts can pertain to multicast groups. Hosts that have the same multicast address are part of the same host group.

In ethernet, a device that receives an electrical signal in one port, interprets the bits and regenerates a clean signal that it sends out all other ports of the hub. Typically it also supplies several ports, which are oftentimes RJ-45 jacks.

a network that incorporates both optical fiber along with coaxial cable to create a broadband network. commonly used by cable tv companies.

defines the commands, headers and processes by which web server and web browsers transfer files.

real-time communication between two or more people through text. The text is conveyed through computers connected over a network such as the internet. files can also be transferred through the IM program to share files.

An international, nonprofit organization for the advancement of technology related to eletricity. IEEE maintains the standards defining many LAN protocols.

a time period between ethernet frames that allows fairness with the CSMA/CD algorithm. Without a space between frames in other words, without some time with no frames being sent a NIC might always listen for silence, never hear silence and therefore never get a chance to send a frame.

a device that connects end devices to the network or interconnects different networks. A router is an example of an intermediary device.

An international standards body that defines many networking standards. Also, the standards body that created the OSI model.

The network that combines enterprise networks, individual users, and ISPs into a single global IP network.

An organization that assigns the numbers important to the proper operation of the TCP/IP protocol and the Internet, including assigning globally unique IP addresses.

a high-speed line or series of connections that forms a major pathway within a network. The term is often used to describe the main network connections comprising the Internet.

As part of the TCP/IP internet layer, ICMP defines protocol messages used to inform network engineeres of how well an internetwork is working. For example, the ping command sends ICMP messages to determine whether a host can send packets ot another host.

The standards body responsible for the development and approval of TCP/IP standards

A company that helps create the Internet by providing connectivity to enterprises and individuals, as well as interconnecting to other ISPs to create connectivity to all other ISPs.

a combination of many IP subnets and networks, as created by building a network using routers. The term internwork is used to avoid confusion with the term network, because an internetwork can include several IP networks.

In the telnet application, commands are always introduced by a character with the decimal code 255, known as the Interpret as Command character.

a corporate system such as a website that is explicitly used by internal employees. Can be assessed internally or remotely

Network layer protocol in the TCP/IP stack offering a connectionless internetwork service. IP provides features for addressing, type-of-service specification, fragmentation and reassembly, and security.

a 32-bit number, written in dotted decimal notation, used by the IP to uniquely identify an interface connected to an IP network. It is also used as a destination address in an IP header to allow routing, and as a source address to allow a computer to receive a packet and to know which IP address to send a response to.

the header defined by the IP. Used to create IP packets by encapsulating data supplied by higher-layer protocol (such as TCP) behind an IP header.

in a shared media ethernet network, a signal generated by the transmitting devices that detects the collision. The jam signal continue to transmit for a specified period to ensure that all devices on the network detect the collision. The jame signal is a part of CSMA/CD