OSI Model and TCP/IP
Two advantages of subnetting
1) It separates the network and subnet address from the host address 2) It divides the network into smaller segments
Class A private address range
10.0.0.0 - 10.255.255.255
How many channels are implemented in 802.11 direct sequence spread spectrum?
14
Class B private address range
172.16.0.0 - 172.31.255.255
Class C private address range
192.168.0.0 - 192.168.255.255
Which wireless standard is prone to interference from Bluetooth, microwaves, and cordless phones?
802.11b
Which wireless standard can provide data transfer rates of 200 Mbps?
802.11n
Smurf
A denial-of-service attack which spoofs the source network address.
Subnetting
A technique used to break down (or partition) networks into subnets.
L2TP
A tunneling protocol related to PPTP and L2F
Network layer
Accepts outgoing messages and combines messages or segments into packets, adding a header that includes routing information. It acts as the network controller. Examples of protocols working in this layer are Inter- net Protocol (IP) and Internetwork Packet Exchange (IPX).
Device used for connecting a wireless device to a network
Access Point
Full IPv6 Address
All 32 hexadecimal positions contain a value other than 0
Supernetting
Allows multiple networks to be specified by one subnet mask.
Session Layer
Allows session establishment between processes running on different stations.
How is port defined for use in TCP/IP?
An address to direct data to a destination application
Frequency Division
Bandwidth is divided into smaller subchannels
Device that forwards broadcasts as is susceptible to broadcast storms
Bridge
Notation specifying the number of bits set to 1 to make up a subnet mask
CIDR
0.0.0.0 - 127.255.255.255
Class A address range
128.0.0.0 - 191.255.255.255
Class B address range
192.0.0.0 - 223.255.255.255
Class C address range
224.0.0.0 - 239.255.255.255
Class D address range
240.0.0.0 - 254.255.255.255
Class E address range
Physical Layer
Concerned with the transmission and reception of the unstructured raw bit stream over the physical medium.
Layer 4-7 hardware
Content service switch, layer 4-7 switches
Network Layer
Controls the operations of the subnet, deciding which physical path the data takes.
Two responsibilities of TCP protocol
Correcting errors, connecting to the host
Multicast Address
Data packets sent to this type of address are sent to the entire group of networking devices, such as a group of routers running the same routing protocol.
Three services provided by a wireless LAN adapter
Delivery of the data, authentication, and privacy.
Transport Layer
Ensures that messages are delivered error-free, in sequence, and with no losses or duplications.
What does a three-way handshake do?
Establishes the TCP connection
Prefix all multicast IPv6 addresses begin with
FF00::/8
Presentation Layer
Formats the data to be presented to the application layer. It can be viewed as the translator for the network.
Data link layer
Handles error recovery, flow control (synchronization), and sequencing (which terminals are sending and which are receiving). It is considered the "media access control layer" and is where Media Access Control (MAC) addressing is defined. The Ethernet 802.3 standard is defined in this area, which is why the MAC address is sometimes called the Ethernet address.
Layer 1 hardware
Hubs, repeaters
What does an IPSec tunnel establishment require for security?
IKE
What is a reason to implement IPv6?
Increased need for mobility
Application layer
Interacts with application programs that incorporate a communication component such as your Internet browser and email. This layer is responsible for logging the message in, interpreting the request, and determining what information is needed to support the request. Examples are Hypertext Transfer Protocol (HTTP) for web browsing, File Transfer Protocol (FTP) for transferring files, and Simple Mail Transfer Protocol (SMTP) for email transmission.
Anycast Address
Is obtained from a list of addresses but is only delivered to the nearest node.
Layer DNS, WWW/HTTP, P2P, Email/POP, SMTP, Telnet, FTP are at
Layer 7
Macrobending
Light escapes into the cladding
Infrared (as it applies to 802.11 physical layer technology)
Light is utilized instead of radio waves
Dispersion
Light pulse spreads out in time
Microbending
Loss caused by mechanical stress
Attenuation
Loss of power as light is propagated
CRC
Method used for error detection in Ethernet packets
what is an advantage of using IPv6 for network addressing?
NO need to use private address space.
CSMA/CA
Network access method used by WLAN devices.
Layer of the TCP/IP stack responsible for establishing a network connection
Network interface
What is the function of IPSec?
Network layer encryption
Network
OSI layer that accepts outgoing messages and combines messages or segments into packets, adding a header that includes routing information.
Session
OSI layer that establishes, manages, and terminate the connections.
Data Link
OSI layer that handles error recovery, flow control, and sequencing.
Application
OSI layer that interprets user requests and determines the information needed to support the request.
Physical
OSI layer that provides electrical and mechanical connectivity
Transport
OSI layer that provides message integrity between source and destination
Presentation
OSI layer that structures the message and translates from one code to another if necessary.
Three technologies firewalls are based on
Packet filtering, proxy server, stateful packet filtering
TCP/IP Transport Layer
Processes a request from a host to ensure a connection
ARP
Protocol used by the Internet layer to query for a network interface match to an IP address.
Data Link Layer
Provides error free transfer of data frames from one node to another over the physical layer.
Session layer
Provides the control functions necessary to establish, manage, and terminate the connections as required to satisfy the user request. Examples of technologies working in this layer are Network File System (NFS) and Structured Query Language (SQL).
Physical layer
Provides the electrical and mechanical connection to the network. Examples of technologies working in this layer are Electronic Industries Alliance/Telecommunications Industry Association (EIAfTIA) related tech- nologies, UTP, fiber, and network interface cards (NICs).
Which technology can a firewall provide?
Proxy server
OSI Transport Layer
Responsible for message integrity between source and destination
Layer 3 hardware
Routers, layer 3 switch
Table used by layer 3 devices to determine where to forward data packets based upon IP addresses
Routing
Application Layer
Serves as the window for users and application processes to access the network services.
Loss of association
Signal failure from the client during a site survey
Breaking down networks into smaller networks
Subnetting
Two or more networks grouped together
Supernet
Specifying multiple networks with one subnet mask
Supernetting
Layer 2 hardware
Switches, bridges
Supernet
The grouping of two or more class networks together.
Stateful Firewall
The inbound and outbound data packets are compared to determine if a connection should be allowed.
Frequency Hopping Spread Spectrum
Transmit signal frequency changes based on a random sequence
Unicast Address
Used to identify a single network interface, and data packets are sent directly to the computer with the specified IPv6 address.
Direct Spread Spectrum
Wide Bandwidth is used to spread the transmitted data
Presentation layer
layer: Accepts and structures the messages for the application. It translates the message from one code to another if necessary. This layer is responsible for data compression and encryption. Examples of technologies working in this layer are American Standard Code for information Interchange (ASCII) and Joint Photographic Experts Group (JPEG).
Transport layer
layer: Is concerned with message integrity between source and destination. It also segments/reassembles (the packets) and handles flow control. Examples of protocols working in this layer are Transmission Control Protocol (TCP) and User Datagram Protocol (UDP).
