A command-line tool for handling packages on Debian-based Linux computers.

A protocol used to map network layer addresses to link layer addresses. Often used for IP to MAC address resolution.

A group of routers that share network prefixes under the administrative control of a single organization.

A Cisco firewall device.

Cisco software used to manage and monitor Cisco security devices.

A specialized circuit that is often proprietary of a particular vendor.

A technology designed for the transfer of voice, video, and data through public and private networks. Largely replaced by MPLS.

The routing protocol of the Internet. BGP uses autonomous systems to exchange route information.

A Unix operating system that was developed in Berkeley, California.

The expert level of certification from Cisco Systems.

The associate level certification from Cisco Systems.

The professional level certification from Cisco Systems.

Software used to manage and monitor Cisco routers.

A Cisco proprietary protocol used to collect hardware and configuration information from directly connected Cisco devices on a network.

A shorthand method of assigning a network mask to an IP address. CIDR uses a slash, followed by the number of binary bits for the mask portion of an IP address; for example, 192.168.1.1 255.255.255.0 is written as 192.168.1.1 /24 in CIDR notation.

The circuitry in a computer that’s responsible for executing code and controlling input/output operations.

A protocol used for dynamically applying IP addresses and other network settings to a host.

A link-local virtual circuit identifier used to assign frames to a PVC or SVC.

A hierarchy of database servers that map Internet hostnames to IP addresses.

A Cisco proprietary advanced distance-vector routing protocol.

A protocol used to transfer files from one host to another using TCP/IP. Also the name of the program that allows a user to transfer files to and from a remote host.

A Cisco proprietary redundant router protocol that supports load-balancing.

A Cisco proprietary redundant router protocol that provides automatic router failover at a default gateway.

A device that monitors network activities for malicious code, usually working in conjunction with a firewall. Unwanted activities trigger alarms that are reported to a system administrator.

Used to describe any program, operation, or device that transfers data to or from a computer or device.

Software that runs on Linux and emulates the features of a Cisco IOS router or switch.

Cisco’s primary router and switch operating system.

Software that runs on Linux/Unix and emulates the features of a Cisco IOS router or switch.

The network layer protocol in the TCP/IP stack that provides routing and logical addressing.

The fourth version of the IP. IPv4 uses a 32-bit address scheme.

The sixth version of the IP. IPv6 uses a 128-bit address scheme.

A Cisco proprietary VLAN trunking protocol, replaced by 802.1Q on modern networks.

A company that provides consumers and businesses with access to the Internet.

A Cisco router model used in small businesses or home offices, usually connected to the Internet using DSL or cable modems. ISR hardware is often designed using application-specific integrated circuits.

The Juniper entry-level associate certification for Junos OS.

A network that connects computers and peripherals within a small geographic area, such as a single building or a group of buildings.

A signaling standard used between routers and Frame Relay switches.

A unique identifier that’s written into the firmware of a network Ethernet card. MAC addresses are used for communication on a physical network segment.

A packet-forwarding technology that uses labels to make data forwarding decisions. Replaces ATM and Frame Relay on modern networks.

The maximum frame size of a protocol data unit. The Ethernet default frame size is 1500 bytes, but it can be reduced or increased depending on your Ethernet hardware and drivers.

A method of using a single IP address on an edge router or firewall so that devices on the network behind the edge device can access networks (like the Internet) beyond the edge using a single IP address. NAT is responsible for rewriting datagram headers to keep track of packets between the edge device and the inside hosts.

Used to describe any program, operation, or device that transfers data to or from a computer or device over a network.

A Cisco chassis card that provides additional functionality to some Cisco router models, such as the c7200.

A type of memory that retains its contents when power is turned off.

Manages a computer’s memory, processes, and all of its software and hardware.

An interior gateway protocol that uses a link-state database and a shortest path first (SPF) algorithm to calculate the best routes to reach a network.

A standard file format used for packaging and distributing virtual appliances that can be run using virtual machine software, such as VirtualBox and VMware.

A communications protocol used for transmitting Point-to-Point Protocol (PPP) packets over SONET.

A permanent connection that’s established between two or more nodes in a Frame Relay or ATM network.

An open source machine emulator and virtualizer.

A type of memory that does not retain its contents when power is turned off.

A distance vector protocol that primarily uses hop count as a metric for choosing the best route to remote networks. Often referred to as routing by rumor.

Used for securely logging into a remote machine and executing commands on a remote machine.

A protocol used to synchronously transfer data over fiber-optic networks.

A dynamic connection that’s established between two or more nodes in a Frame Relay or ATM network.

Creates and manipulates streaming archive files.

The connection-oriented transport layer of the TCP/IP stack. TCP is responsible for creating reliable end-to-end connections.

TFTP allows users to transfer files to and from a remote machine using no authentication or error correction.

A connectionless transport layer protocol that does not use handshaking. UDP exchanges datagrams without acknowledgments.

Cisco’s network simulation platform that includes virtual machines running Cisco’s core network operating systems.

A mechanism for partitioning a layer-2 network into separate broadcast domains.

A program that emulates specific hardware and allows you to install and run operating systems designed for that hardware.

A virtual hard disk image file that is often used by virtual machine software, such as VMware, VirtualBox, and QEMU.

A simple program that simulates the basic networking features and commands of a PC.

A group of security protocols that allow two devices to share encrypted information over a public network (like the Internet).

A software client for Cisco VPN3000 Concentrator, IOS devices, and PIX devices.

An open standard redundant router protocol that provides automatic router failover at a default gateway.

A network that covers a wide geographic range, often made up of multiple networks connected using one or more VPNs.

A Cisco proprietary interface card that often provides serial port interfaces to a router.