More Test1 Review Flashcards
Router(symbol)
circle with 2 arrows in & 2 arrows out
Switch(symbol)
square with two arrows facing left & 2 facing right.
HUB(symbol)
square with double-sided arrow (pointing left & right)
Server(symbol)
3-D rectangle.
Bridge(symbol)
square with sunken top.
Ethernet/LAN(symbol)
solid line
WAN(symbol)
lightning bolt
Hardware firewall(symbol)
3-D brick wall
Repeater
amplifies a signal
Multiplexer(MUX)
turns many inputs into one output
Modem
changes signal from WAN to LAN
wireless access point(WAP)
self-explanatory
wireless range extender
similar to repeater - amplifies signal
Bridge
old version of a switch (predecessor of modern switches). It’s called a bridge because there’s only 2 ends. Connects one network segment to only one other
Network interface card(NIC)
allows a device to connect to the internet
Network address translator(NAT)
translates private IP to public IP address & vice versa.
Bus topology
every component/computer shares the same line. Only one device at a time can send a signal over the bus
ring topology
like a bus but both ends are connected in a circle. devices use tokens to communicate. used when devices must run in a particular order, like a nuclear power plant.
star topology
HUB or switch in middle and all devices connected to it. Device sends signal to HUB. once it receives a signal/packet in a port, it will distribute it to all other ports on the network. not very efficient. Physically a star but logically a bus
HUB & spoke
only used for routers
full mesh
All nodes connected to all others. number of links = n(n-1)/2 where n is the number of nodes
client/server (C/S) mode
client requests a service from server
Peer-to-peer (P2P)
both nodes function as a client & server
Which layers can communicate with each other in the OSI model?
Only neighboring layers
port for world wide web
80
port for ssh
22
of bits in IPV4 & IPV6
32 & 128
media access control (MAC) address
a unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment
Layers of OSI model
7 - Application 6 - Presentation 5 - Session 4 - Transport 3 - Network 2 - Data Link 1 - Physical
Data unit for physical layer
Bits
Data unit for data link layer
frames
Data unit for network layer
packets
Data unit for transport layer
segments
TCP/IP stack layers
Application
Transport
Internet
Network interface
What layers do the Network interface layer of the TCP/IP stack correspond to in the OSI model?
Data link & physical
What layers does the application layer of the TCP/IP stack correspond to in the OSI model?
Application
presentation
session
Physical layer purpose
This is how bits are represented on the medium. Controls bit rate control & synchronization, bandwidth usage, etc.
Physical layer components
Cat 6, Cat 7, RJ-45 standards, physical topologies, broadband or baseband, multiplexing (TDM/FDM)
Data link layer purpose
Responsible for node-to-node delivery of the message and makes sure data transfer is error-free from one node to another, over the physical layer. Connection services, flow control, error control, synchronization, physical addressing, & framing.
Data link layer components
Media access control(MAC), logic link control(LLC)
network layer purpose
Transmits data from one host to the other located in different networks. Also does routing. Involves logical addressing, switching, route discovery & selection, connection services.
network layer components
IP addressing, packet/circuit/message switching, routing protocols
transport layer purpose
TCP/UDP. Flow control(windowing, buffering), error control. Provides services to app layer and takes services from network layer. Represents end-to-end delivery of entire message.
Session layer purpose
setting up & maintaining & tearing down a session. Also authentication & security, synchronization & dialog controller.
presentation layer purpose
aka translation layer. Data formatting(ASCII), encryption, data compression.
App layer purpose
HTTP, FTP, SMTP. Produces data which has to be transferred over the network. Functions = virtual network terminal, mail services, file transfer. directory services.
3 types of IP address & what they do
unicast - single source device to single destination device.
Broadcast - single source to all devices on network
Multicast - single source to multiple, but specific, devices on a network
Class A IP address starting digit & range of first octet
first bit = 0
range: 0-127
Class B IP address starting digits & range of first octet
first bit = 10
range: 128-191
Class C IP address starting digits & range of first octet
first bit = 110
range: 192-223
Class D IP address starting digits & range of first octet
first bit = 1110
range: 224-239
reserved for multicasting
Class E IP address starting digits & range of first octet
first bit = 1111
range: 240-255
reserved for future use
Structure of IPV6 address
ABCD:0123:4040:0000:0000:0000:000A:000B
Written in hex separated by colons
IPV6 abbreviations
Leading 0’s can be omitted, contiguous groups of 0’s can be represented as double colon.
ABCD:123:4040::A:B
IPV6 network address range
First 48 bits are for internet routing
IPV6 subnet range
16 bits from the 49th to 64th
Device (interface) range
last 64 bits
Regional internet registry(RIR)
Guidelines for assigning IPV6 addresses to countries. Minimum of 12 prefix bits.
IPV6 anycast
Traffic travels for a single source device to the nearest of multiple, but specific, devices on a network
APIPA
Automatic Private IP Addressing. Used when a device does not have a static IP address and/or cannot contact a DHCP server. Allows a network device to assign itself an IP address.
Default Gateway
A router that knows how to forward packets on to other networks.
BOOTP
Older dynamic addressing protocol. Assigned only IP, subnet mask, & default gateway.
DHCP
Based on BOOTP. Assigns IP, subnet mask, & default gateway. Assigns DNS server & other variables related to VoIP
DHCP 4-way handshake
Client/server.
Discovery ->