What are the three basic network configurations?
Centralized
Peer to peer
Server base
A system of independent computers that are interconnected together to share data and resources is called______________.
Network
Which basic network configuration uses “dumb terminals” along with a mainframe computer?
Centralized computing
_______ is the standard for optical transport and is capable of transmitting data in excess 1Gbps
Sonet
The most popular physical network architecture in use today Is called________.
Eithernet
The ________ topology uses cable segments from each computer that are connected to a centralized component such as a hub.
Star
A system of rules and procedures that govern communications between two or more devices on a network is called a ___________.
Protocol
The _________ layer in protocol stack ensures that packets are delivered error free and in sequence.
Transport
Which transport protocol category establishes, maintains and breaks a connection with the receiving system?
Connection -oriented
The user datagram protocol (UDP) falls under the ________ ________ classification.
Connectionless oriented
What concept of TCP/IP prevent network congestion by ensuring transmitting devices do not overwhelm receiving device with data?
Flow control
A______ is the combination of an IP address and a port number.
Socket
An example of an exterior routing protocol used to link several LAN/MANs together is the _________ _________ __________.
Border gateway protocol
What protocol layer transmits the unstructured, raw bit stream over a physical medium?
Physical layer
The______ __________ ___________ is the United States representative to the international organization of standardization.
American national standards institute (ANSI)
What is the term for a standard development by a company for that company’s products only?
Propriety
The ___________ is a standard that has been officially approved by a recognized standards committee.
De Jure standard
List the three specifications for the 802 series of standards.
- type of network interface card
- components for LAN, MAN, WAN
- layout of connection pins
What IEEE 802 category defines standards for broadband wireless?
802.16
What IEEE 802 category defines standards for wireless LAN networks?
802.11
What device is designed to establish, maintain, and terminate a connection and transfer data without regards to the contents?
DCE
A ________ is a device that is added to a network to extend the length of a cable.
Repeater
A ______ is a device that can connect two or more LAN segments together and uses software to preform switching functions.
Bridge
Which device function as a translator between systems using different protocols on the same network?
Gateway
A______ creates a virtual private network through a process called “tunneling”
VPN connection
What type of clock uses an atomic resonance frequency standard as it’s time keeping element?
Atomic clock
_________ is the process by which a subject professes an identity and accountability is initiated.
Identification
What are the six methods of identification and authentication?
Knowledge base (password) Poisson-based (token) Biometric- base( fingerprint) Combining method Ticket authentication Sign on
Which I&A method that uses a token that the system can recognize by the host is called________.
Possession based
_________ methods provide a high level of security because authentication is directly related to a “users behavior or physiological characteristic.
Biometric
The use of prescribed safeguard and controls to prevent reconstruction of sensitive or classified information is called__________.
Remanence security
Which method of destruction removes classified and sensitive information from media to render the information unrecoverable by technical means?
Sanitizing media
_____________ is the DOD’s practical strategy for achieving information assurance in today’s network-dependent environments.
Defense in depth.
What are the three elements that make up the defense in depth strategy?
People
Operation
Technology
What is the second element of the defense in depth strategy that focuses on all the activities required to sustain an organizations security on a day-to-day basis?
Operations
_____________ is a network architectural concept design for network security as established by the Air Force
Barrier reef
___________ is what protects the bases “network perimeter” in accordance to Air Force security policies
Boundary protection
The ______________ router is controlled by the integrated network operations and security center (INOSC) and is the first line of defense for Air Force bases.
Air Force SDP
A pice of hardware or software program that examines data passing into your computer or network is called a _____________.
Firewall
An__________ system scans, audits and monitors the security infrastructure for signs of unauthorized access or abuse in progress.
Intrusion detection
The ability to identify and report vulnerabilities at the host and network level to protect resources directly managed by NCC is called _____________.
Internal control
___________ limits access to base systems based on roles or identification that reflects the degree of the users need-to-know and privileges.
Access control
What is the procedural method that provides the capability to prioritize and guarantee network access to traffic at various levels of mission criticality?
Access preservation
What are the three sanctioned tools that from the foundation of combat information transport system (CITS)?
Internet security system(ISS)
Intruder alert
Enterprise security manger (ESM)
The __________ performs automated, distributed or event-driven probes of geographically dispersed network services and prioritized scan results and remediation information in clear reports that allow users to respond quickly to critical vulnerabilities.
Internet security system
___________ is an agent based intrusion detection tool used by INOSC and NCC operations to detect unauthorized activity on selected network hosts, key servers, and critical workstations.
Intruder alert
Which Air Force approved tool runs on a management server and has agents installed on hosts to run checks based on vulnerabilities of a particular operating system.
Enterprise security manger
The two primary goals of anti-virus software are______ and _______.
Prevention
Detection
Automated security incident measurement system (ASIMS) logs all connections and looks for suspicious events that enter a _______ network.
Base
A network__________ policy focuses on controlling the network traffic and usage.
Security
What are the three types of perimeter networks?
Outmost perimeter
Internal perimeter
Innermost perimeter
The_______ network is the most insecure area of your network infrastructure.
Outermost
A ___________ is an access control device, performing perimeter security by determining which packets are allowed or denied into a network.
Firewall
What filtering firewall works by examining packets and comparing them to a list of rules based on source of data, intended destination, and the port number the data was sent from?
Packet filtering firewall
A____________ firewall examines more than just addresses and port information of the data by looking deeper at the actual application data.
Stateful packet inspection
_______ management is the process of detecting, isolating and correcting network problems.
Fault
What are the five network management domains as defined by IOS?
Fault management Configuration management Account management Performance management Security management
Periodically the network management software can send out a message to others devices asking them for their status which is called?
Polling
The final step in fault management is called ______ the problem
Fix
The goal of _______ _________ is to monitor network and system configurations so the effect on network operations of various versions of hardware and software can be tracked and managed.
System configuration
Storing data in a database such as relational database management system (RDMS) to allow quick access to the number of routers in a building falls under _______ management.
Configuration
“Fine tuning” a network operations capabilities fall under__________.
Performance
_________ is combination of protocols, each layer has it own set of rules and defines the rules of each layer in the OSI reference model
Protocol stack
What is the management of network usage, costs, charges and access to resources?
Account management
The goal of _________ management is to ensure all users have adequate network resources and they are regulated and distributed accordingly.
Account
Securing access points to sensitive information on a network is part of _________ management
Security
True/false
Security management under FCAPS deals with physical and operating system security.
False
As part of security management ________ _______ ________ should be used to provide a basic level of security for accessing a network.
Access control lists (ACL)
The final step in security management is _________ the secure access points.
Maintaining
_________________ are another name for communication computer facility records.
Central office records
______ is a datebase designed to proactively manage small, medium, and large scale enterprise network from local, regional, and central locations simultaneously.
CAIRS OSS
Which software was adopted by the Air Force as the standard application to generate and maintain telephone central office records?
Telecommunications management system
TMS
What is another name for the action request system?
Remedy action request system
A central point to receive help on various computer issue is called a__________.
Help desk
The connection protocol that just sends out the packet to the receiving system and does not check to see if it was received?
Connectionless-oriented
TCP/IP uses what connectionless transport protocol?
User Datagram Protocol (UDP)
What is UDP best used for?
To send small amounts of data for which guaranteed delivery is not required and minor packet loss can be tolerated (VOIP, video-confereincing, streaming audio and video, online games)
Does UDP use windowing or acknowledgments?
No
What protocols use UDP?
TFTP, SNMP, DHCP, DNS
What is the 3rd layer of the OSI model?
Network layer (N3twork)
What is the transport layer responsible for?
logical addressing and routing of the data packets from the source to the destination network device
Network Layer protocols are divided into what 2 categories?
Routed and Routing
What are the 2 things a protocol describes?
The format a message must take, and the way computers must exchange a message within the context of a particular activity
What is a Routed Protocol?
A network layer protocol that provides enough information in its header to allow a packet/segment/frame to be forwarded from one host to another based on the addressing through the router
Is Internet Protocol (IP) a routed protocol?
Yes
Define IP
Connectionless, unreliable, best-effort delivery system protocol
What 5 parts make up an IP packet?
Source and destination address, protocol identifier, checksum, time to live (TTL)
What is TTL (Time to live)
It tells each router between source and destination how long the packet has to remain on the network, by counting seconds, hops, or both
What are the 8 protocols that IP uses as its carrier to pass through a router?
DNS, FTP, HTTP, SMTP, SNMP, ICMP, Telnet, SSH
Define DNS
Domain Name System. Translates names of domains and their publicly advertised network nodes on to IP addresses
Define FTP
File Transfer Protocol. Download and upload files from the internet
Define HTTP
Hyper Text Transfer Protocol. Identifies to the browser what protocol should be used
Define SMTP
Simple Mail Transfer Protocol. Email servers use it to send and receive email using TCP
Define SNMP
Simple Network Management Protocol. Facilitates the exchange of management information between network devices. Allows network managers to monitor traffic.
Define ICMP
Internet Control Message Protocol. Sends and recieves status reports about information being transmitted. Often used to control flow between routers.
Define Telnet (aka VTY)
Terminal Emulation. Software to remotely access another device. Often used for remote admin of routers and switches. BANNED by the Air Force on the operational network
Define SSH
Secure Shell. Network protocol allowing data to be exchanged using a secure channel between 2 networked devices. Provides encryption for confidentiality and integrity of data on an unsecure network
What is a Routing Protocol?
Supports a routed protocol by providing mechanisms for sharing routing information. Routing protocol messages move between the routers to update and maintain tables
What are the 2 classes of routing protocols?
Interior Gateway Protocols (IGPs) and Exterior Gateway Protocols (EGPs). Classified by how the operate with regard to an Autonomous System
Interior routing protocols operate where?
Inside a local network
What are the 5 interior routing protocols?
RIP, IGRP, EIGRP, OSPF, IS-IS
Define RIP
Routing Information Protocols. Uses hop count to determine the direction and distance to any link in the internetwork. Selects the path with fewest hops
Define IGRP
Interior Gateway Routing Protocol. Selects fastest path based on delay, bandwidth, load, and reliability. Has much higher max hop count than RIP
Define EIGRP
Enchanced Interior Gateway Routing Protocol. Uses a 32 bit metric and faster convergence and lower-overhead bandwidth for superior operating efficiency. AKA hybrid.
Define OSPF
Open Shortest Path First. Developed for IP networks because RIP was incapable of service large intranets
Define IS-IS
Intermediate System-to-Intermediate System. Dynamic link-state routing protocol for the OSI protocol stack
What is theone example given of an exterior routing protocol?
Border Gateway Protocol (BGP).
Define BGP
Border Gateway Protocol (BGP). Exchanges routing information between autonomous systems while guaranteeing loop-free path selection. Principle routing protocol for ISPs and major companies
What is the name of the OSI Layer 2?
Data-Link layer
What does the Data Link layer do?
Conditions and controls data frames between the Network Layer and the Physical Layer. Encapsulates the datagram from the Network layer with physical addressing, network toplogy, error notification, sequencing of frames and flow control
What is the information called when it is in the Data Link layer?
Frame
What is a Cell?
Information unit of fixed size whose source and destination are Data Link layer entities
The Data Link layer is broken in to what 2 layers?
Logical Link Control (LLC) and Media Access Control address (MAC Address)
Define LLC
Logical Link Control (LLC). Interface between the Network layer and MAC sublayer. Establishes and terminates links, controls, sequences and acknowledges frames
Define MAC
Media Access Control. Manages media access, checking frame errors, recognizing frame address
What is the name of the OSI Layer 1?
Physical Layer
Define the physical layer
Transmits the unstructured raw bistream over a physical medium. Totally hardware oriented, it also defines how the cable attaches to the NIC (shape, # of pins)
What are the two Mediac Access Techniques?
Centralized Access Control and Distributed Access Control
Define Centralized Access Control
Workstations are not allowed to xmit until they receive a query from the central controller (Method called “Polling”)
Define Distributed Access Control
Each station shares responsibility for access control, uses Random Access and Deterministic Access (xmit at any time vs. each waiting a turn)
Random Access Methods are contention-based. T/F?
TRUE
What is the example of Random Access Method given in the book?
Collision Sense Multiple Access with Collision Detection (CSMA/CD)
What happens if a collision occurs with CSMA/CD?
Stations use a “back off” period before xmitting again
What are the two Deterministic Access Methods given?
Token Passing and Slotted Access
Define Token Passing
Most popular, a station must wait for the token to be passed to it to xmit and then passes the token on. Determines WHEN but not AMOUNT of data to be sent
Define Slotted Access
Empty dataframe is passed among the stations. Restricts WHEN and AMOUNT of data that can be xmitted
The International Oganization for Standardization (ISO) developed what model?
7-layer OSI Reference Model
Define ANSI’s job
US representative to the ISO. Creates and publishes standards for programming, comm, networking
Define the ITU
International Telecommunications Union. UN agency to develop and standardize comm. Has 3 sub-agencies
What are the 3 subagencies of the ITU?
ITU-T, ITU-R, ITU-D
What standards does IEEE define?
Standards related to networking
What does the EIA set standards for?
Consumer products and electronic components (e.g. RS-232 cable)
What standards does TIA devlop?
Communication Standards (e.g. EIA/TIA-568-B connector, aka RJ-45)
What does the IAB do?
Oversees the development of internet standards and protocols, especially IP addressing
What is the old name for NIST?
National Bureau of Standards
What is the independent, non-profit standardization org for telecomm industry in Europe with worldwide projection?
ETSI
What is the original Military Standard tactical and long haul comm?
Military Standard 188 (MIL-STD-188)
Which MIL-STD is closely associated with Cyber Transport?
MIL-STD-188-114
Define a Proprietary Standard
Standard developed for a company for that company’s products only. They sometimes “lock” a user into a single vendor’s product
Define a Non-proprietary or Open Standard
Widely accepted standard designed to apply to equipment and software regardless of the manufacturer. Very advantageous when it comes to networking
Define De Facto standard
A vendor’s standard that is so widely used to becomes a standard WITHOUT any formal path of implementation
Define De Jure standard
A standard that has been officially approved by a recognized standards committee. Usually non-proprietary
What are the 3 parts to the Hardware Interface?
Physical Interface, Electrical Interface, Functional Interface
What Interface defines the number of pins, wires, and how they are arranged and attached?
Physical Interface
What Interface defines the magnitude, duration, and sign of electrical signals?
Electrical Interface
What Interface defines the interpretation of signals on each wire
Functional Interface
IEEE 802 provides specifications on what 3 things?
Type of network interfaces and cards to use, components for the LAN/MAN/WAN and wireless connection, layout of the connector pins
What is required when taking a signal from one format to another?
Converter
Basically, what does a Transceiver do?
Both transmits and receives analog or digital signals
What is a transceiver most commonly used for today?
Applies signals onto the network wire and detects signals passing through the wire
Define a NIC
Network Interface Card. Enables a PC to be attached to some sort of network cabling by providing a physical connection point and electrical signal conversion
What type of address is associated with every NIC?
A MAC address
The MAC Address belongs in what layer?
Data-Link layer
What layers does the NIC work in?
Both the physical Itransceiver and connectors )and data-link layers (controller)
Define DTE
Data Terminal Equipment. Any digital device at the user end which xmits or rcvs data and uses communication equipment for data transfer
Define DCE
Data Communications Equipment. Devices connected to a communication line for the purpose of transferring data from one point to another. They also establish, maintain, and terminate the connection
What are 5 examples of DCE given in the book?
Modems (most common), hubs, repeaters, bridges, switches
Define a Hub
Layer 1 device, broadcasts any packet entering on one port to all other ports
Define a Repeater
Layer 1 device, compensates for loss of a DIGITAL signal. No filtration or processing done to signal; any signal in is repeated out
Define a Bridge
Layer 2 device, connects 2 or more LAN segments to effectively make one logical network
Define a Switch
Layer 2 device, can interconnect LANs of different bandwidth and provide collision-free, high speed comm between network devices
Define a Gateway
Converts protocols, languages, and architecture to allow communications between different systems but do not alter the original data (Think PC to Mac communication). Slow and expensive
Define a Router
Layer 3 device, Connect two or more network semgents and support dynamic path assignment
The connection protocol that just sends out the packet to the receiving system and does not check to see if it was received?
Connectionless-oriented
TCP/IP uses what connectionless transport protocol?
User Datagram Protocol (UDP)
What is UDP best used for?
To send small amounts of data for which guaranteed delivery is not required and minor packet loss can be tolerated (VOIP, video-confereincing, streaming audio and video, online games)
Does UDP use windowing or acknowledgments?
No
What protocols use UDP?
TFTP, SNMP, DHCP, DNS
What is the 3rd layer of the OSI model?
Network layer (N3twork)
What is the transport layer responsible for?
logical addressing and routing of the data packets from the source to the destination network device
Network Layer protocols are divided into what 2 categories?
Routed and Routing
What are the 2 things a protocol describes?
The format a message must take, and the way computers must exchange a message within the context of a particular activity
What is a Routed Protocol?
A network layer protocol that provides enough information in its header to allow a packet/segment/frame to be forwarded from one host to another based on the addressing through the router
Is Internet Protocol (IP) a routed protocol?
Yes
Define IP
Connectionless, unreliable, best-effort delivery system protocol
What 5 parts make up an IP packet?
Source and destination address, protocol identifier, checksum, time to live (TTL)
What is TTL (Time to live)
It tells each router between source and destination how long the packet has to remain on the network, by counting seconds, hops, or both
What are the 8 protocols that IP uses as its carrier to pass through a router?
DNS, FTP, HTTP, SMTP, SNMP, ICMP, Telnet, SSH
Define DNS
Domain Name System. Translates names of domains and their publicly advertised network nodes on to IP addresses
Define FTP
File Transfer Protocol. Download and upload files from the internet
Define HTTP
Hyper Text Transfer Protocol. Identifies to the browser what protocol should be used
Define SMTP
Simple Mail Transfer Protocol. Email servers use it to send and receive email using TCP
Define SNMP
Simple Network Management Protocol. Facilitates the exchange of management information between network devices. Allows network managers to monitor traffic.
Define ICMP
Internet Control Message Protocol. Sends and recieves status reports about information being transmitted. Often used to control flow between routers.
Define Telnet (aka VTY)
Terminal Emulation. Software to remotely access another device. Often used for remote admin of routers and switches. BANNED by the Air Force on the operational network
Define SSH
Secure Shell. Network protocol allowing data to be exchanged using a secure channel between 2 networked devices. Provides encryption for confidentiality and integrity of data on an unsecure network
What is a Routing Protocol?
Supports a routed protocol by providing mechanisms for sharing routing information. Routing protocol messages move between the routers to update and maintain tables
What are the 2 classes of routing protocols?
Interior Gateway Protocols (IGPs) and Exterior Gateway Protocols (EGPs). Classified by how the operate with regard to an Autonomous System
Interior routing protocols operate where?
Inside a local network
What are the 5 interior routing protocols?
RIP, IGRP, EIGRP, OSPF, IS-IS
Define RIP
Routing Information Protocols. Uses hop count to determine the direction and distance to any link in the internetwork. Selects the path with fewest hops
Define IGRP
Interior Gateway Routing Protocol. Selects fastest path based on delay, bandwidth, load, and reliability. Has much higher max hop count than RIP
Define EIGRP
Enchanced Interior Gateway Routing Protocol. Uses a 32 bit metric and faster convergence and lower-overhead bandwidth for superior operating efficiency. AKA hybrid.
Define OSPF
Open Shortest Path First. Developed for IP networks because RIP was incapable of service large intranets
Define IS-IS
Intermediate System-to-Intermediate System. Dynamic link-state routing protocol for the OSI protocol stack
What is theone example given of an exterior routing protocol?
Border Gateway Protocol (BGP).
Define BGP
Border Gateway Protocol (BGP). Exchanges routing information between autonomous systems while guaranteeing loop-free path selection. Principle routing protocol for ISPs and major companies
What is the name of the OSI Layer 2?
Data-Link layer
What does the Data Link layer do?
Conditions and controls data frames between the Network Layer and the Physical Layer. Encapsulates the datagram from the Network layer with physical addressing, network toplogy, error notification, sequencing of frames and flow control
What is the information called when it is in the Data Link layer?
Frame
What is a Cell?
Information unit of fixed size whose source and destination are Data Link layer entities
The Data Link layer is broken in to what 2 layers?
Logical Link Control (LLC) and Media Access Control address (MAC Address)
Define LLC
Logical Link Control (LLC). Interface between the Network layer and MAC sublayer. Establishes and terminates links, controls, sequences and acknowledges frames
Define MAC
Media Access Control. Manages media access, checking frame errors, recognizing frame address
What is the name of the OSI Layer 1?
Physical Layer
Define the physical layer
Transmits the unstructured raw bistream over a physical medium. Totally hardware oriented, it also defines how the cable attaches to the NIC (shape, # of pins)
What are the two Mediac Access Techniques?
Centralized Access Control and Distributed Access Control
Define Centralized Access Control
Workstations are not allowed to xmit until they receive a query from the central controller (Method called “Polling”)
Define Distributed Access Control
Each station shares responsibility for access control, uses Random Access and Deterministic Access (xmit at any time vs. each waiting a turn)
Random Access Methods are contention-based. T/F?
TRUE
What is the example of Random Access Method given in the book?
Collision Sense Multiple Access with Collision Detection (CSMA/CD)
What happens if a collision occurs with CSMA/CD?
Stations use a “back off” period before xmitting again
What are the two Deterministic Access Methods given?
Token Passing and Slotted Access
Define Token Passing
Most popular, a station must wait for the token to be passed to it to xmit and then passes the token on. Determines WHEN but not AMOUNT of data to be sent
Define Slotted Access
Empty dataframe is passed among the stations. Restricts WHEN and AMOUNT of data that can be xmitted
The International Oganization for Standardization (ISO) developed what model?
7-layer OSI Reference Model
Define ANSI’s job
US representative to the ISO. Creates and publishes standards for programming, comm, networking
Define the ITU
International Telecommunications Union. UN agency to develop and standardize comm. Has 3 sub-agencies
What are the 3 subagencies of the ITU?
ITU-T, ITU-R, ITU-D
What standards does IEEE define?
Standards related to networking
What does the EIA set standards for?
Consumer products and electronic components (e.g. RS-232 cable)
What standards does TIA devlop?
Communication Standards (e.g. EIA/TIA-568-B connector, aka RJ-45)
What does the IAB do?
Oversees the development of internet standards and protocols, especially IP addressing
What is the old name for NIST?
National Bureau of Standards
What is the independent, non-profit standardization org for telecomm industry in Europe with worldwide projection?
ETSI
What is the original Military Standard tactical and long haul comm?
Military Standard 188 (MIL-STD-188)
Which MIL-STD is closely associated with Cyber Transport?
MIL-STD-188-114
Define a Proprietary Standard
Standard developed for a company for that company’s products only. They sometimes “lock” a user into a single vendor’s product
Define a Non-proprietary or Open Standard
Widely accepted standard designed to apply to equipment and software regardless of the manufacturer. Very advantageous when it comes to networking
Define De Facto standard
A vendor’s standard that is so widely used to becomes a standard WITHOUT any formal path of implementation
Define De Jure standard
A standard that has been officially approved by a recognized standards committee. Usually non-proprietary
What are the 3 parts to the Hardware Interface?
Physical Interface, Electrical Interface, Functional Interface
What Interface defines the number of pins, wires, and how they are arranged and attached?
Physical Interface
What Interface defines the magnitude, duration, and sign of electrical signals?
Electrical Interface
What Interface defines the interpretation of signals on each wire
Functional Interface
IEEE 802 provides specifications on what 3 things?
Type of network interfaces and cards to use, components for the LAN/MAN/WAN and wireless connection, layout of the connector pins
What is required when taking a signal from one format to another?
Converter
Basically, what does a Transceiver do?
Both transmits and receives analog or digital signals
What is a transceiver most commonly used for today?
Applies signals onto the network wire and detects signals passing through the wire
Define a NIC
Network Interface Card. Enables a PC to be attached to some sort of network cabling by providing a physical connection point and electrical signal conversion
What type of address is associated with every NIC?
A MAC address
The MAC Address belongs in what layer?
Data-Link layer
What layers does the NIC work in?
Both the physical Itransceiver and connectors )and data-link layers (controller)
Define DTE
Data Terminal Equipment. Any digital device at the user end which xmits or rcvs data and uses communication equipment for data transfer
Define DCE
Data Communications Equipment. Devices connected to a communication line for the purpose of transferring data from one point to another. They also establish, maintain, and terminate the connection
What are 5 examples of DCE given in the book?
Modems (most common), hubs, repeaters, bridges, switches
Define a Hub
Layer 1 device, broadcasts any packet entering on one port to all other ports
Define a Repeater
Layer 1 device, compensates for loss of a DIGITAL signal. No filtration or processing done to signal; any signal in is repeated out
Define a Bridge
Layer 2 device, connects 2 or more LAN segments to effectively make one logical network
Define a Switch
Layer 2 device, can interconnect LANs of different bandwidth and provide collision-free, high speed comm between network devices
Define a Gateway
Converts protocols, languages, and architecture to allow communications between different systems but do not alter the original data (Think PC to Mac communication). Slow and expensive
Define a Router
Layer 3 device, Connect two or more network semgents and support dynamic path assignment
