NETWORK+ Flashcards
PASS THE EXAM
1
Q
Layer 1 (OSI)
A
PHYSICAL: physical layer is where the raw bitstream is physically transmitted over a physical medium
BONUS
(includes translating bits to electricity, light, or radio signals and controlling the rates at which they are sent over the chosen medium)
2
Q
Layer 1 PDU
A
bits
3
Q
Layer 2 (OSI)
A
DATA LINK: establishes and terminates a connection between two physically-connected nodes on a network. It breaks up packets into frames and sends them from source to destination.
4
Q
Layer 2 PDU
A
frames
5
Q
Layer 3 (OSI)
A
NETWORK: One is breaking up segments into network packets, and reassembling the packets on the receiving end. The other is routing packets by discovering the best path across a physical network.
6
Q
Layer 3 PDU
A
packets
7
Q
Layer 4 (OSI)
A
TRANSPORT:accept data from the session layer, split it up into smaller units if need be, pass these to the Network layer, and ensure that all the pieces arrive correctly at the other end.
8
Q
Layer 4 PDU
A
segments
9
Q
Layer 5 (OSI)
A
SESSION: creates communication channels, called sessions, between devices
-Start, Stop, Restart
10
Q
Layer 5 PDU
A
data
11
Q
Layer 6 (OSI)
A
PRESENTATION: takes any data transmitted by the application layer and prepares it for transmission over the session layer; encrypts, SSL/TSL
12
Q
Layer 6 PDU
A
data
13
Q
Layer 7 (OSI)
A
APPLICATION: used by end-user software such as web browsers and email clients. It provides protocols that allow software to send and receive information and present meaningful data to users.
(HTTP,POP3, FTP, DNS, SMTP)
14
Q
Layer PDU
A
data
15
Q
TCP Flags
A
In the protocol header, TCP uses flags to manage connections and traffic flows.
16
Q
SYN
A
SYNCHRONIZATION: Used to create a TCP connection
17
Q
ACK
A
ACKNOWLEDGMENT: Used to acknowledge the reception of data or synchronization packets
18
Q
PSH
A
PUSH: Instruct the network stacks to bypass buffering
19
Q
URG
A
URGENT: Indicates out-of-band data that must be processed by the network stacks before normal data
20
Q
FIN
A
FINISH: Gracefully terminate the TCP connection
21
Q
RST
A
RESET: Immediately terminate the connection and drop any in-transit data
22
Q
Payload
A
Data sent in terms of packets and individual packets containing a header and the data which is sent by the sender
23
Q
MTU
A
Maximum Transmission Unit
-a measurement representing the largest data packet that a network-connected device will accept. (smaller=faster)
24
Q
IP Header
A
smallest message entity exchanged via the Internet Protocol across an IP network. consist of a header for addressing and routing, and a payload for user data.
25
Ethernet Header
contains destination and source MAC addresses as its first two fields.
26
TCP Header
tracks the state of communication between two TCP endpoints. (slower than UDP) 20-60 bits
27
UDP Header
source port, destination port, packet length (header and data), and a simple (and optional) checksum
28
Mesh Topology
a network configuration in which computers are linked to one another by numerous redundant connections.
(no switch or hub)
29
Star Topology (Hub and Spoke)
connects each node to a central hub
30
Bus Topology
network communication takes place over a single bus or channel. network communication takes place over a single bus or channel
31
Ring Topology
a type of network configuration where devices are connected in a circular manner, forming a closed loop
32
Hybrid Topology
made up of two or more topologies
(expenisve , needs MSAL)
33
P2P
Peer to Peer
- a decentralized platform whereby two individuals interact directly with each other, without intermediation by a third party. (equally privileged)
34
Client-Server
consists of a single central computer functioning as a server and directing several other computers(clients)
35
LAN
Local Area Network
-a collection of devices connected together in one physical location, such as a building, office, or home.
36
MAN
Metropolitan Area Network
-a computer network that connects computers within a metropolitan area,
(bigger than LAN, smaller than WAN)
37
WAN
Wide Area Network
-spans beyond a single building or large campus to include multiple locations spread across a specific geographic area, or even the world.
38
WLAN
Wireless Local Area Network
-links two or more devices using wireless communication to form a local area network within a limited area such as a home, school, computer laboratory, campus, or office building.
(ex wifi)
39
PAN
Personal Area Network
-connects electronic devices within a user's immediate area
40
CAN
Campus Area Network
-made up of an interconnection of local area networks within a limited geographical area.
41
SAN
Storage Area Network
-network of storage devices that can be accessed by multiple servers or computers, providing a shared pool of storage space. Each computer can access storage on the SAN as though they were local disks connected directly to the computer.
42
SDWAN
Software Defined Wide Area Network
- a virtual WAN architecture that allows enterprises to leverage any combination of transport services – including MPLS, LTE and broadband internet services – to securely connect users to applications.
43
MPLS
Multiprotocol Label Switching
- routes traffic using the shortest path based on “labels,” rather than network addresses, to handle forwarding over private wide area networks.
(technique for speeding up network connections)
44
mGRE
Multipoint Generic Routing Encapsulation
-connect multiple remote sites through a VPN
multiple endpoints, resulting in a point to multipoint topology.
45
GRE
Generic Routing Encapsulation
-developed by Cisco Systems that can encapsulate a wide variety of network layer protocols inside virtual point-to-point links or point-to-multipoint links over an Internet Protocol network
46
Demarcation Point
the point at which the telephone company's wiring ends and the customer's wiring begins
(public to private)
47
Smartjack
(intelligent network interface device, INID)
similar to NID but with newer technology and additional features. commonly used for complex types of telecom services, such as T1 lines (Verizon)
48
vSwitch
Virtual switches are also used to establish connections between virtual and physical networks and to carry a VM's traffic to other VMs or a physical network.
49
vNic
a virtualized Network Interface Card, used by a Virtual Machine as its network interface.
A VNIC is assigned a MAC address
50
NFV hypervisor
Network functions virtualization
-replacement of network hardware with virtual machines. The virtual machines use a hypervisor to run networking software and processes such as routing and load balancing.
51
Hypervisor
a software that you can use to run multiple virtual machines on a single physical machine
52
Leased Lines
a reserved circuit between two communication points that is always active and rented monthly.
Leased lines are dedicated, meaning that any bandwidth associated with the leased line is solely for private, organizational use.
53
Broadband
various high-capacity transmission technologies that transmit data, voice, and video across long distances and at high speeds
54
ADSL
Asymmetric digital subscriber line
- a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide.
55
DOCSIS
Data Over Cable Service Interface Specification
-international telecommunications standard that permits the addition of high-bandwidth data transfer to an existing cable television system.
56
Cat 5
100Mbs
100mhz
1000Base-T
57
Cat 5e
1Gbps (1000Mbs)
100mhz
1000Base-T
58
Cat 6
10Gbps
250mhz
10GBase-T
Unshielded: 55 m
Shielded: 100 m
59
Cat 6a
10Gbps
500mhz
10GBase-T
60
Cat 7
10Gbps
600mhz
10GBase-T
61
Cat 8
40Gbps
2000mhz
40GBase-T
62
RG-6
Coaxial cable and satellite signal transmission for residential or commercial installations
63
Twinaxial
similar to coaxial cable, but with two inner conductors in a twisted pair instead of one
(cheap fast)
64
T568A
White/Green
Green
White/Orange
Blue
White/Blue
Orange
White/Brown
Brown
65
T568B
White/Orange
Orange
White/Green
Blue
White/Blue
Green
White/Brown
Brown
66
SMF
Single-Mode Fiber
-a single glass fiber strand used to transmit a single mode or ray of light
(laser, higher bandwiths)
67
MTRJ
Mechanical Transfer Registered Jack
-the connector houses two fibers and mates with locating pins on the plug.
(small form factor)
68
APC
Angled Physical Connect
- 8°angel, minimizing the back reflection as a result
(GREEN)
69
UPC
Ultra Physical Contact
-polished with no angle
(BLUE)
70
F-Type connector
"over the air" terrestrial television, cable television and universally for satellite television and cable modems,
(RG-6/U r RG-59/U cable)
71
SFP
Small Form-Factor Pluggable
-provide required optical or electrical reach via copper or fiber optic cables
(transmit and receive at same time)
72
SFP+
Enhanced Form-Factor Pluggable
-an updated SPF version that supports higher speeds up to 10Gbps
73
QSFP
Quad Small Form-Factor Pluggable
-supports a maximum data transfer rate of up to 4 Gbps
74
QSFP+
Enhanced Quad Small Form-Factor Pluggable
-supports a higher data transfer rate of up to 10 Gbps
75
Punchdown block 66
older blocks which only supported up to CAT3
76
Punchdown block 110
support up to CAT6 and provide better bandwidth
77
Krone Punchdown block
European/UK connector
open-ended contact slots at a 45-degree angle to the wire
78
Bix Punchdown block
proprietary block developed originally by Nortel Networks.
79
10BASE T
maximum speed of 10 Mbps, uses twisted-pair copper cabling
(home networks and small businesses)
80
100BASE TX
maximum speed of 100 Mbps and also uses twisted-pair copper cabling to connect devices
(large LAN's, office networks)
81
100BASE FX
1300nm multimode light.
maximum length: 2 kilometers for full duplex over multimode optical fiber.
82
100BASE SX
850nm light
-up to 300 meters.
-lower cost alternative to 100Base-FX
83
1000BASE SX
850nm multimode light over multimode fibers.
maximum length is 500 m, can reach longers
84
1000BASE LX
1300 or 1310nm single mode fiber and laser.
maximum lenght 5km-10km
85
10GBASE SR
a port type for multi-mode fiber and uses 850 nm lasers
86
10GBASE LR
10-Gbps Ethernet standard that operates at ranges of up to 25 kilometers two 1310-nm single-mode fibers
87
CWDM
Coarse Wavelength-Division Multiplexing
-up to 18 wavelength channels transmitted over a dark fiber at the same time.
wavelenghts:1310nm and 1550nm.
70km
88
DWDM
Dense Wavelength-Division Multiplexing
-up to 80 simultaneous wavelength channels, 0.8nm apart.
connections can be amplified, used for transmitting data much longer distances.
89
Bidirectional WDM
Bidirectional wavelength-division multiplexing
-transmission of optical channels on a fiber propagating simultaneously in both directions.
90
RFC1918
networking equipment assigns IP addresses in a private network.
91
NAT
Network Address Translation
- a way to map multiple private addresses inside a local network to a public IP address before transferring the information onto the internet
92
PAT
Port Address Translation
-allows a single public IP address to be used by multiple devices within a private network.
accomplished by assigning each device a unique port number and routing incoming traffic accordingly.
93
APIPA
Automatic Private IP Addressing
-devices automatically assign IP addresses to themselves when they cannot get an IP address from a Dynamic DHCP
94
EUI-64
Extended Unique Identifier
-allows a host to assign iteslf a unique 64-Bit IP Version 6 interface identifier
(no need for manual DHCP in IPv4
95
Multicast
one-to-many and many-to-many real-time communication over an IP infrastructure in a network
(simultaneously)
96
Unicast
one-to-one transmission from one point in the network to another point
(one sender, one receiver)
97
Anycast
multiple machines to share the same IP address, sent to closest device
98
MMF
Multimode fibers
-for transporting light from a laser source to the place where it is needed
99
Broadcast
ensures each node's transmissions are received by all other nodes in the network; single communications channel
100
Multicast IPV6 range
FF00::/8
-one to may
101
Unicast IPV6 range
FC00::7
-packets to interface, private network
102
Global Unicast IPV6 range
2000::/3
-internet routing
103
Link-local address IPV6 range
FE80::/10
-non-routable (like APIPA)
104
Link Local
automatically assign IP address when no other assignment method available (like APIPA)
105
Loopback address
127.0.0.1
-allows the machine to connect to and communicate with itself
106
Default Gateway
address of your router/ modem
(hardware that sits between user's home network and the rest of the internet)
107
Classless VLSM
Variable Length Subnet Mask
- all subnet masks can have varying sizes.
enables network engineers to use multiple masks for different subnets of a single class A, B or C network.
108
Class A public
1-127
-255.0.0.0
large number of hosts
109
Class A private
10.0.0.0 to 10.255.255.255
110
Class B public
128-191
-255.255.0.0
medium to large sized networks
111
Class B private
172.16.0.0 to 172.31.255.255
112
Class C public
192-223
-255.255.255.0
small local area networks (LANs).
113
Class C private
192.168.0.0 to 192.168.255.255
114
Class D
224-239
not allocated to hosts and are used for multicasting
115
Class E
240-255C
reserved for research purposes
116
CIDR
Classless Inter-Domain Routing
-IP address and a suffix that indicates network identifier bits in a specified format
ex: /24
117
Tunneling
allows for the movement of data from one network to another.
(encapsulation TCP, VPN encryption, private across public)
118
Dual Stack
supports the simultaneous use of both IPv4 and IPv6 addresses
119
Router Advertisement
for IPv6 auto-configuration and routing.
When enabled, messages are sent by router periodically and in response to solicitations
120
SLAAC
Stateless Address Auto-Configuration
-enables each host on the network to auto-configure a unique IPv6 address without device keeping track of which address is assigned to which node.
121
Subinterfaces
virtual interface created by dividing one physical interface into multiple logical interfaces
(layer 3)
122
DHCP Scope
range of IP addresses that a DHCP server can distribute to clients on a specific network segment.
defines the pool of available addresses
123
DHCP Exclusion Ranges
addresses taken from a DHCP scope that the DHCP server is not allowed to hand out
124
DHCP Reservation
lets you assign a specific IP address to a specific device or whenever the device connects to the network
125
DHCP Lease Time
default lease time for the DHCP server is 24 hours
126
DHCP Relay
provides a way for DHCP clients to communicate with DHCP servers when none are available on its local subnet
127
IP Helper/UDP Forwarding
forward broadcast and multicast packets received for a specific IP address
128
CNAME
Canonical Name
-resource record in the Domain Name System that maps one domain name to another.
(convenient when running multiple services from a single IP address)
129
MX
Mail Exchange
-a DNS record that routes emails to specified mail servers
130
SOA
State of Authority (DNS)
-the email address that you used to register your domain
131
PTR
Pointer (DNS)
-provides the domain name associated with an IP address
(opposite of "A")
132
TXT
Text
-stores text notes on a DNS serverS
133
SRV
Service
-used to identify computers hosting specific services
(locate controllers in AD)
134
NS
Name Server
-indicates which DNS server is authoritative for that domain
135
Root DNS servers
the topmost part of a website's address and represents the ground level of the website's identity
EX: poop.com
136
Zone Transfers
process of copying the contents of the zone file on a primary DNS server to a secondary DNS server
137
Authoritative Name Severs
the final holder of the IP of the domain you are looking for.
138
TTL
like a stopwatch for how long to keep a DNS record.
139
DNS Caching
temporary DNS storage on a device that contains DNS records of already visited domain names, uses TTL
140
Reverese DNS
takes an IP address and returns the domain name associated with that IP
141
Reverse Lookup
resolve IP addresses to names
142
Forward Lookup
resolve names to IP addresses
143
Recursive Lookup
one DNS server communicates with several other DNS servers to hunt down an IP address and return it to the client
144
Irerative Lookup
client communicates directly with each DNS server involved in the lookup.
145
NTP
Network Time Protocol
-protocol that allows the synchronization of system clocks (from desktops to servers)
146
Stratum
hierarchy of time servers in an NTP network
Stratum level (0-15) indicates the device's distance to the reference clock
147
Access/Edge
Part 1: part of the network which enables the users to connect to the wired Ethernet Network
(Ethernet Switches, Hubs)
148
Distribution/Aggregation Layer
Part 2: network grows beyond a certain size, it must be divided into multiple local (Access Layer) networks
(Routers)
149
Core
Part 3:
backbone of a network, used to connect multiple Distribution Layer devices together
(most powerful layer, fiber, redundancy)
150
Software Defined Network
a network architecture approach that enables the network to be intelligently and centrally controlled, or 'programmed,' using software applications
151
Application Layer (SDN)
network programs and applications that communicate the desired network behavior and requirements to the underlying SDN control layer.
152
Control Layer (SDN)
connects the application layer and the infrastructure layer
(admin control)
153
Infrastructure Layer (SDN)
underlying network of physical switches and routers in the network
These devices forward network traffic to their destinations based on rules/policies from controller.
154
Management Plane
handles high-level network management and operations including network monitoring and customer billing
155
Spine and Leaf
data center network topology that consists of two switching layers—a spine and leaf
156
Top-of-Rack Switching
uses network switches to connect servers and other devices in the same rack
157
Backbone
part of computer network which interconnects networks, providing a path for the exchange of information between different LANs or subnetworks
158
SAN
Storage Area Network
159
FCoE
Fibre Channel over Ethernet
enables Fibre Channel (FC) communications to run directly over Ethernet.
160
Fibre Channel
connect computer data storage to servers in storage area networks (SAN) in commercial data centers.
161
iSCSI
Internet Small Computer Systems Interface
-allows the SCSI command to be sent end-to-end over local-area networks (LANs), wide-area networks (WANs) or the internet
162
SaaS
Software as a service
-allows users to connect to and use cloud-based apps over the Internet
(office 365, pay as you go)
163
IaaS
Infrastructure as a Service
-provides on-demand access to computing resources such as servers, storage, networking, and virtualization
(hardware)
164
PaaS
Platform as a Service
-includes everything developers need to build, run, and manage applications
(test, programming)
165
DaaS
Desktop as a Service
-a service provider delivers virtual desktops to end users over the Internet, licensed with a per-user subscription
166
IaC
Infrastructure as code
ability to provision and support your computing infrastructure using code instead of manual processes and settings
167
VPN
virtual private network
- stay private online by encrypting the connection between your device and the internet
168
Layer 2 Switch
used to reduce data traffic on a LAN
(MAC address only)
169
Layer 3 Switch
operate VLANs and improve security
(routing between network segments)
170
Hub
connects multiple PCs to a single network
(OSI layer 1)
171
Switch
connects multiple devices on a single computer network
172
Bridge
creates a single, aggregate network from multiple communication networks or network segments
173
load balancer
process of distributing traffic among multiple servers to improve a service or application's performance and reliability.
174
Proxy Server
agent or intermediary for the user, passing through all Web requests and responses.
175
Repeater
node that amplifies incoming signals and rebroadcasts them over a wider area or higher network layer than the original signal.
176
Voice Gateway
used to connect the enterprise VoIP network with the telecommunications provider
177
IPS
Intrusion Prevention System
-takes action to block the attempted intrusion or otherwise remediate the incident.
178
IDS
Intrusion Destection System
-provide an alert about a potential incidentF
179
Firewall
monitors incoming and outgoing network traffic and decides whether to allow or block specific traffic based on a defined set of security rules.
180
VPN Headend
termination point for the VPN tunnels
181
RIP
Routing Information Protocol
- distance-vector protocol that uses hop count to determine the best path
(distance:120)
182
OSPF
Open Shortest Path First
-a link-state routing protocol used to find the best path between the source and the destination router using its own Shortest Path First
(distance:110)
183
EIGRP
Enhanced Interior Gateway Routing Protocol
- a distance-vector protocol to automate routing configuration and decisions on a network.
(distance:90)
(hybrid of link state and distance vector)
184
BGP
Border Gateway Protocol
- exterior gateway protocol that enables exchange of routing and reachability info between autonomous systems (AS) on the internet.
185
Link State
send info about directly connected links to all the routers in the network
186
Distance Vector
send their entire routing table to directly connected neighbors
187
Default Route
the route that takes effect when no other route is available for an IP destination address
188
Administrative distance
a measure of the trustworthiness of the source of the routing information
(lower better/wins)
189
Traffic Shaping (packet shaping)
bandwidth management technique that delays the flow of certain types of network packets in order to ensure network performance for higher priority applications.
190
QoS
Quality of Service
-refers to any technology that manages data traffic to reduce packet loss, latency and jitter on a network.
191
port tagging/802.1q
trunk ports will link switches, and access ports will link to end devices
(802.3)
192
LACP
Link Aggregation Control Protocol
- enables you to bundle several physical ports together to form a single logical channel (LAG)
(802.3az)
193
Full Duplex
simultaneous data transmission and receptions over one channel.
device capable of bi-directional network data transmissions at the same time
194
Half Duplex
devices can only transmit in one direction at one time
195
Flow Control
ensures that the transmitting device does not send more data to the receiving device than it can handle
196
Port Mirroring
on a network switch to send copy of network packets seen on one switch port (or an entire VLAN) to a network monitoring connection on another switch port.
197
Port Security
enables you to configure each switch port with a unique list of the MAC addresses of devices that are authorized to access the network through that port.
198
Jumbo Frames
Ethernet frames with more than 1500 bytes of payload, limit set by IEEE 802.3 standard
(up to 9000 bytes)
199
MDIX
auto-medium-dependent interface crossover
-automatically detects the required cable connection type and configures the connection appropriately
200
MAC address table
media access control address tables
where the switch stores information about the other Ethernet interfaces to which it is connected on a network
201
PoE
Power over Ethernet
802.3af , an deliver 15.4 watts over Cat5 cables.
202
PoE+
Power Over Ethernet +
802.3at ,can deliver up to 30 watts over Cat 5 cables with 25.5 watts available to devices.
203
STP
Spanning Tree Protocol
IEEE 802.1D, a loop-prevention protocol that allows switches to communicate with each other in order to discover physical loops in a network.
(layer 2)
204
Blocking (STP)
Receives BPDUs only
When a device is connected, the port will first enter the blocking state
205
Listening (STP)
The switch will listen for and send BPDUs.
206
Learning (STP)
Builds bridging table
The switch will receive a superior BPDU, will stop sending its own BPDUs, and will relay the superior BPDUs.
207
Forwarding (STP)
Sends/receives user data
The port is forwarding traffic.
208
Disabled (STP)
The result of an administrative command that will disable the port.
209
CSMA/CD
Carrier-sense multiple access with collision detection
-use a shared medium, where multiple devices connect to the same physical network segment.
(MAC)
210
ARP
Address Resolution Protocol
-connects an always-changing IP address to a fixed media access (MAC) address
211
NDP
Neighbor Discovery Protocol
-ability of an IPv6 host to automatically generate its own IPv6 address
212
802.11a
5GHz
20MHz
54Mbps
(WiFi 2) (OFDM)
213
802.11b
2.4GHz
20MHz
11Mbps
(WiFi 1) (DSSS)
214
802.11g
2.4GHz
20MHz
54Mbps
(WiFi 3) (DSSS, OFDM)
215
802.11n
2.4GHz/5.4GHz
20MHz/40MHz
600Mbps
(WiFi 4)(OFDM, MIMO)
216
802.11ac
5GHz
20/40/80/160MHz
1.3Gbps
(WiFi 5) (OFDM, MU-MIMO)
217
802.11ax
2.4GHz/5.4GHz
20/40/80/160MHz
10-12Gbps
218
SSID
Service Set Identifier
219
BSS
Basic Service Set (1 AP)
-group of wireless devices served by a a single Access Point (AP)
220
ESS
Extended Service Set (more than 1 AP)
-User can go from one cell to another without connection interrupt. combining one more Access Point in a switched network
221
IBSS
Independent Basic service Set (Ad Hoc, 0 AP)
-directly communicate together without any need to an Access Point
222
WPA
Wi-Fi Protected Access
-used TKIP 256 bit
( temporal key integrity protocol)
223
WPA2 personal (PSK)
relies on a shared passcode for access and is usually used in home environments.
(AES, Advanced Encryption Standard)
224
CDMA
Code-division multiple access
- protocols used in (3G and 2G) wireless communication
225
GSM
Global System for Mobile Communications
-(2G) standard employing time-division multiple-access (TDMA) spectrum-sharing, issued by the European Telecommunications Standards
226
MIMO
Multiple-Input Multiple-Output
-wireless technology that uses multiple transmitters and receivers to transfer more data at the same time
227
Mu-MIMO
multi-user, multiple input, multiple output
-allows a single access point (AP) to transmit data to multiple devices simultaneously.
802.11ac Wave 2 (Wi-Fi 5)
228
Bandwith
how much data can be downloaded or uploaded from your computer
229
Latency
amount of time it takes for a data packet to go from one place to another
230
Jitter
time delay between when a signal is transmitted and when it's received over a network connection
231
Traps
SNMP PDU
an agent can send an unrequested message to the manager to notify about an important event.
232
OID
Object Identifier
-an address that is used to differentiate between devices within the MIB hierarchy
233
MIB
Management Information Base
-formatted text file within the SNMP manager designed to collect information and organize it into a hierarchical format
234
Traffic Logs
whenever traffic hits a rule which has been enabled for logging
235
Audit Logs
produced and stored on the device each time a user makes a change to the configuration of a device.
236
Syslog
a protocol that computer systems use to send event data logs to a central location for storage.
237
Syslog level 0
Emergency- system is unusable
238
Syslog level 1
Alert-action must be taken immediately
239
Syslog level 2
Critical-critical conditions
240
Syslog level 3
Error - error conditions
241
Syslog level 4
Warning - warning conditions
242
Syslog level 5
Notice - normal, but significant condition
243
Syslog level 6
Informational - informational messages
244
Syslog level 7
Debug - debug level messages
245
CRC
cyclic redundancy check
- network method designed to detect errors in the data and information transmitted over the network
246
CRC error
when a device (network device or host connected to the network) receives an Ethernet frame with a CRC value in the FCS field of the frame that does not match the CRC value
247
Giant Frame
any frame whose size exceeds the maximum transmission unit (MTU) passes 1500bytes
248
Runt frame
a frame that is smaller than the minimum frame size for IEEE-802.3 standard frames (ethernet 64bytes)
249
Encapsulation error
indicates that router has a layer 3 packet to forward and is lacking some element of the layer 2 header that it needs to be able to forward the packet toward the next hop.
250
Baelines
a snapshot, a collection of metrics about a network at a time of normal use
251
Netflow Data
Source and destination IP address
(TCP/UDP)
252
Change Management
collective term for all approaches to prepare, support, and help individuals, teams, and organizations in making organizational change
253
Incident Response Plan
written document, formally approved by the senior leadership team, that helps your organization before, during, and after a confirmed or suspected security incident.
254
Disaster Recovery Plan
process of maintaining or reestablishing vital infrastructure and systems following a natural or human-induced disaster
255
AUP
document outlining rules and guidelines for using an organization's IT resources, including networks, devices, and software
defines acceptable and prohibited behaviors
256
Onboarding and offboarding employee
procedures that mark the beginning and conclusion of an employee's tenure with an organization
257
Data Loss Prevention
identifies and helps prevent unsafe or inappropriate sharing, transfer, or use of sensitive data
258
Floor Plan
identifies and helps prevent unsafe or inappropriate sharing, transfer, or use of sensitive data
259
Rack Diagram
visual representation of the organization of IT equipment within a server rack used to track and manage data center assets.
260
IDF
intermediate distribution frame
-a remote room or closet connected to the MDF, in which you can expect to find hubs and patch panels.
261
MDF
Main Distribution Frame
-main computer room for servers, hubs, routers, DSL's, etc. to reside
262
Logical network Diagram
illustrates the flow of information through a network and shows how devices communicate with each other
263
Wiring Diagram
A diagram that shows how a circuit works logically and electrically
264
site survey report
helps visualize the wireless network coverage areas and data rates.
265
Baseline Configurations
or gold build, is the standard, approved configuration of a system.
266
NDA
non-disclosure agreement
-a legally binding contract that establishes a confidential relationship.
protect their intellectual property and confidential information
267
SLA
service-level agreement
-agreement between a service provider and a customer.
268
MOU
memorandum of understanding
-nonbinding agreement that states each party's intentions to take action, conduct a business transaction, or form a new partnership.
269
Multipathing
creating more than one physical path between the server and its storage devices. (SAN)
270
Load Balancing
the method of distributing network traffic equally across a pool of resources that support an application.
271
NIC teaming
Network Interface Card teaming
- process of combining multiple network cards together for performance, load balancing, and redundancy reasons
272
Switches
allows two or more IT devices, such as computers, to communicate with one another.
273
Routers
managing traffic between networks by forwarding data packets to their intended IP addresses, and allowing multiple devices to use the same Internet connection.
274
Firewalls
barrier between two networks identifying and blocking cyber threats while allowing appropriate traffic through.
275
UPS
uninterruptible power supply
- provide backup power, protecting equipment from damage in the event of grid power failure
276
PDU
power distribution unit
- a device with multiple power outlets that provides electrical protection and distributes power to IT equipment within a rack
277
Active-active
Client machines connect to a load balancer that distributes their workloads across multiple active servers
278
Active-passive
Client machines connect to the main server, which handles the full workload, while a backup server remains on standby, only activating in the event of a failure.
279
VRRP
Virtual Router Redundancy Protocol
- IP routing redundancy protocol designed to allow for transparent failover at the first-hop IP router.
280
FHRP
first hop redundancy protocol
- protect the default gateway used on a subnetwork by allowing two or more routers to provide backup for that address
281
MTTR
Mean time to repair
-the average time it takes to repair a system
282
MTBF
Mean Time Between Failure
-measures the mean time between repairable product or service failures
283
RTO
Recovery Time Objective
-measures the quantity of time that passes during an incident before reaching the business continuity plan’s (BCP) threshold of acceptability
284
RPO
Recovery Point Objective
-defines the quantity of data (or service time) that can be lost before unacceptable consequences occur.
285
CIA
confidentiality, integrity and availability
286
CVE
common vulnerabilities and exposures
-system provides a reference method for publicly known information-security vulnerabilities and exposures.
287
Zero Day
vulnerability or security hole in a computer system unknown to its owners, developers or anyone capable of mitigating it.
288
Least Privelege
a user is given the minimum levels of access – or permissions – needed to perform his/her job functions.
289
Role Based Access
a method of restricting network access based on the roles of individual users within an enterprise
290
Zero Trust
no one is trusted by default from inside or outside the network, and verification is required from everyone trying to gain access to resources on the network
291
Defense in depth
strategy that leverages multiple security measures to protect an organization's assets
292
network segmentation enforcement
network security technique that divides a network into smaller, distinct sub-networks
293
Perimeters Network (DMZ)
a separate network used for placing web servers, e-mail servers, FTP servers and other public servers to gain access from or to the internet.
294
Separation of Duties
an attempt to ensure that no single individual has the capability of executing a particular task/set of tasks.
295
NAC
Network Access Control
-the process of restricting unauthorized users and devices from gaining access to a corporate or private network.
296
Honeypot
designed to look, feel, and act just like a network packed tight with valuable resources (to catch hackers)
297
TACACS+
Terminal Access Controller Access-Control System
used for administrative access to network devices such as routers and switches or devices in the network
-separates Authentication, Authorization, and Accounting.
298
RADIUS
Remote Authentication Dial-In User Service
-a networking protocol that authorizes and authenticates users who access a remote network.
299
Kerberos
protocol for authenticating service requests between trusted hosts across an untrusted network, such as the internet
300
802.1X (NAC)
authenticates the port, and port security manages network access for all MAC addresses, including that of the client
301
EAP
Extensible Authentication Protocol
-used to pass the authentication information between the supplicant (the Wi-Fi workstation) and the authentication server (Microsoft IAS or other)
302
posture assessment
builds a baseline view of your organisation's security capabilities end-to-end. The ultimate aim of such an assessment is to build maturity in the organisation's cyber resilience strategy to minimise the risk of cyber-attacks and data breaches.
303
SIEM
Security information and event management
-is a security solution that helps organizations detect threats before they disrupt business.
304
On path attack (MITM)
attackers place themselves between two devices (often a web browser and a web server) and intercept or modify communications between the two
305
DNS Poisoning
fake info is entered into the cache of a domain name server, resulting in DNS queries producing an incorrect reply, sending users to the wrong website.
306
VLAN Hopping
allows an attacker to send frames to a device on a different VLAN.
307
ARP Spoofing
attack in which a malicious actor sends falsified ARP (Address Resolution Protocol) messages over a local area network. results in the linking of an attacker's MAC address with the IP address of a legitimate computer or server on the network.
308
Rogue DHCP
DHCP server on a network which is not under the administrative control of the network staff
309
Rogue AP
Rogue Access Point
-a wireless access point plugged into an organization's network that the security team does not know exists.
310
Evil Twin
An evil twin attack is a rogue Wi-Fi access point (AP) that masquerades as a legitimate one,
311
MITM
when a hacker or compromised system sits in between two uncompromised people or systems and deciphers the information they're passing to each other, including passwords
312
Mac Spoofing
a commonly employed tactic by malicious actors to alter the Media Access Control (MAC) address of their device to mimic that of another device present on the network.
313
IP Spoofing
creation of Internet Protocol packets with a false source IP address, for the purpose of impersonating another computing system
314
deauthentication
sending deauthentication frames to target devices, causing them to disconnect from the network and temporarily denying them access
315
RA Guard
Router Advertisement Guard
provides support for allowing the network administrator to block or reject unwanted or rogue router advertisement (RA) guard messages that arrive at the network device platform.
316
Port Security
enables you to configure each switch port with a unique list of the MAC addresses of devices that are authorized to access the network through that port.
317
DAI
Dynamic ARP Inspection
protects networks against man-in-the-middle ARP spoofing attacks
318
Control Plane Policing
mechanism that allows us to policy the coming traffic to the Control Plane.
319
Private VLANs
LAN is used to connect a group of devices such as computers and printers to a server via cables, VLANs allow multiple LANs and associated devices to communicate via wireless internet.
320
Disable unneeded switchports
Unused or “empty” ports within any network device pose a security risk, as someone might plug a cable into them and connect an unauthorised device to the network
321
Enable DHCP snooping
snooping feature determines whether traffic sources are trusted or untrusted.
322
ACL
Access Control List
-made up of rules that either allow access to a computer environment or deny it
323
Role-based access
a method of restricting network access based on the roles of individual users within an enterprise
324
Firewall Explicit/Implicit deny
Explicitly allows traffic that matches the rule to pass, and then implicitly denies everything else
disallows any traffic through the firewall that isn't explicitly (specifically created rule) set.
325
- Wireless client isolation
"client isolation," "AP isolation" and "SSID isolation," prevents users on a Wi-Fi network from reaching other devices in the same Wi-Fi network (SSID) as well as computers and servers in the wired network
326
PSK
Preshared keys
-secret key that has been established between the parties who are authorized to use it by means of some secure method
327
EAP
Extensible Authentication Protocol
-used to pass the authentication information between the supplicant (the Wi-Fi workstation) and the authentication server (Microsoft IAS or other).
328
Geofencing
allows businesses to target specific geographic areas and deliver personalized, location-based content or offers to their target audience
329
Site-to-site VPN
allow multiple users' traffic to flow through each VPN tunnel
330
Client-to-site VPN
a type of VPN that connects a single device, such as a laptop or smartphone, to a remote network, such as a corporate or cloud network.
331
clientless vpn
Users connect through a web browser and use HTTPS connections
332
Split tunnel
sending part of your traffic through a VPN and part of it through the open network
333
full tunnel
using your VPN for all your traffic,
334
VNC
Virtual network computing
is a screen-sharing tool that also lets the remote computer take control.
(RDP doesn't screen share)
335
In-band management
used to manage devices through telnet/SSH, using the network itself as a media
336
out-of-band management
uses terminal server that is connected to a management port of each controlled device.
337
Detection methods
-Camera
- Motion detection
- Asset tags
- Tamper detection
338
Prevention methods
- Employee training
- Access control hardware
- Badge readers
- Biometrics
- Locking racks
- Locking cabinets
- Access control vestibule
(previously known as a mantrap)
- Smart lockers
339
Asset disposal
- Factory reset/wipe configuration
- Sanitize devices for disposal
340
1.network troubleshooting methodology
Identify the problem:
- Gather information
- Question users
- Identify symptoms
- Determine if anything has changed
- Duplicate the problem, if possible
- Approach multiple
problems individually
341
2.network troubleshooting methodology
Establish a theory of probable cause:
- Question the obvious
- Consider multiple approaches
- Top-to-bottom/
bottom-to-top OSI model
- Divide and conquer
342
3.network troubleshooting methodology
Test the theory to determine the cause:
- If the theory is confirmed, determine
the next steps to resolve the problem
- If the theory is not confirmed,
reestablish a new theory or escalate
343
4.network troubleshooting methodology
Establish a plan of action to resolve the
problem and identify potential effects
344
5.network troubleshooting methodology
Implement the solution or
escalate as necessary
345
6.network troubleshooting methodology
Verify full system functionality
and, if applicable, implement
preventive measures
346
7.network troubleshooting methodology
Document findings, actions,
outcomes, and lessons learned
347
Throughput test
Ping, Iperf, and Wireshark
348
Rollover cable
type of null-modem cable that is used to connect a computer terminal to a router's console port
349
Crossover cable
to connect two computers or similar devices directly together, such as computers or hubs
350
Attenuation
loss of communication signal strength that is measured in decibels.
351
Open
When an intended connection is missing
352
Short
unintended connection exists
353
Duplex Mismatch
causes problems when both ends of the connection attempt to transfer data at the same time
354
TX/RX reverse
Transmit and receive reversed
-occurs when a cross over cable is used with two devices that should be using a straight through cable
355
Wire Map
a simple test that confirms that each wire is terminated correctly, with no opens or shorts
356
OTDR
Optical Time Domain Reflectometer
-device that tests the integrity of a fiber cable and is used for the building, certifying, maintaining, and troubleshooting fiber optic systems.
357
Fusion splicers
the machine used to weld (fuse) two optical fibers together
358
Spectrum Analyzers
measures and displays signal amplitude (strength) as it varies by frequency within its frequency range (spectrum)
359
Fiber light meter
a special light meter that measures how much light is coming out of the end of the fiber optic cable
360
Protocol analyzer
to monitor data traffic and analyze captured signals as they travel across communication channels.
361
Port Scanner
probe a host or server to identify open ports
362
iperf
measure throughput
363
Netflow Analyzers
monitoring, troubleshooting, and in-depth examination, interpretation, and analysis of network traffic flow data.
364
RSSI
Received Signal Strength Indicator
-relative received signal strength in a wireless environment, in arbitrary units
365
TFTP server
Trivial File Transfer Protocol (UDP/69)
a simple protocol for exchanging files between two TCP/IP machines
366
EIRP
Equivalent isotropic radiated power
-the total radiated power from a transmitter antenna times the numerical directivity of the antenna in the direction of the receiver
367
Routing Table
data table stored in a router or a network host that lists the routes to particular network destinations, and in some cases, metrics associated with those routes.
368
VLAN Assignment
It allows authentication, authorization, and accounting of remote users who want to access network resources
(RADIUS)
369
Network Performance Baseline
a set of metrics used in network performance monitoring to define the normal working conditions of an enterprise network infrastructure
370
Collisons
when two or more data packets try to occupy the same network channel at the same time.
371
Multicast Flooding
a way to distribute routing protocols updates quickly to every node in a large network.
372
Switching loops
when network switches are connected together in such a way that network traffic loops around infinitely instead of traversing the hops needed to travel from source to destination
373
Asymmetrical routing
has multiple routes for incoming and outgoing network traffic.
374
Routing loops
an issue that occurs when the routers forward packets such that the same single packet ends up back at the same router
375
AAAA
Authentication, Authorization,
Accounting, Auditing
-maps a domain name to the IP address (Version 6) of the computer hosting the domain.
376
AES
Advanced Encryption Standard
-an algorithm that uses the same key to encrypt and decrypt protected data
377
BNC
British Naval Connector/Bayonet Neill-Concelman
-miniature quick connect/disconnect radio frequency connector used for coaxial cable
378
CAM
Content Addressable Memory (table)
-system memory construct used by Ethernet switch logic which stores information such as MAC addresses available on physical ports with their associated VLAN Parameters.
379
CRC
Cyclic Redundancy Check
a network method designed to detect errors in the data and information transmitted over the network
380
CSMA/CA
Carrier-Sense Multiple
Access with Collision Avoidance
- reduce the frequency of these collisions and provide a plan at the same time on how to proceed if a collision does occur
381
CSU
Channel Service Unit
-converts a digital data frame from local area network (LAN) communication technology into a frame appropriate for a wide area network (WAN) and vice versa.
382
DLP
Data Loss Prevention
-identifies and helps prevent unsafe or inappropriate sharing, transfer, or use of sensitive data
382
DWDM
Dense Wavelength Division Multiplexing
-an optical transmission technology that uses multiple wavelengths of light to combine several data streams onto a single optical fiber.
382
DSU
Data Service Unit
converts a digital data frame from local area network (LAN) communication technology into a frame appropriate for a wide area network (WAN) and vice versa. (CSU/DSU)
383
EIA
Electronic Industries Association
-specializes in ensuring compatibility and interchangeability between equipment from different manufacturers.
383
EUI
Extended Unique Identifier
a method we can use to automatically configure IPv6 host addresses
384
ESP
encapsulating security payload
authentication mechanism authenticates only the IP datagram portion of the IP packet.
385
GBIC
Gigabit Interface Converter
- modular transceiver that is typically used to connect a device, such as a switch or router, to a network via a fiber optic or copper cable.
386
GSM
Global System for Mobile Communications
-European Standard
387
HA
High Availability
-operate at a high level, continuously, without intervention, for a given time period.
387
ICS
Industrial Control System
-combinations of control components (e.g., electrical, mechanical, hydraulic, pneumatic) that act together to achieve an industrial objective
388
IGMP
Internet Group Management Protocol
-a protocol that allows several devices to share one IP address so they can all receive the same data
388
MAC
Media Access Control/Medium Access Control
-layer that controls the hardware responsible for interaction with the wired or wireless transmission medium.
389
mGRE
Multipoint Generic Routing Encapsulation
-used to connect multiple remote sites through a VPN
390
MIB
Management Information Base
-a hierarchical database that contains configuration and other vital management information of SNMP devices in the form of data objects.
390
NAS
Network Attached Storage
-a file-dedicated storage device that makes data continuously available for employees to collaborate effectively over a network.
391
NFV
Network Function Virtualization
- virtual machines use a hypervisor to run networking software and processes such as routing and load balancing.
392
NGFW
Next-Generation Firewall
-security appliance that processes network traffic and applies rules to block potentially dangerous traffic.
Newer firewall, better
393
NIC
Network Interface Card
-a hardware component, typically a circuit board or chip, installed on a computer so it can connect to a network.
394
OSI
Open Systems Interconnection
-a framework for transmitting messages between any two entities in a network
395
PAT
Port Address Translation
-an extension of Network Address Translation (NAT) that permits multiple devices on a LAN to be mapped to a single public IP address to conserve IP addresses.
395
PTR
Pointer Record
-provides the domain name associated with an IP address. (DNS, opposite of "A")
396
QoS
Quality of Service
-control traffic and ensure the performance of critical applications with limited network capacity.
397
RFC
Request for Comment
-contains specifications and organizational notes about topics related to the internet and computer networking, such as routing, addressing and transport technologies.
398
RTSP
Real Time Streaming Protocol
-a network protocol used for controlling the delivery of real-time multimedia data, such as audio and video, over IP networks
399
SCADA
Supervisory Control and Data Acquisition
-used for controlling, monitoring, and analyzing industrial devices and processes
399
SFP
Small Form-factor Pluggable
-allows devices to communicate with one another through data transmission
399
SIP
Session Initiation Protocol
-a signaling protocol that enables the Voice Over Internet Protocol (VoIP) by defining the messages sent between endpoints and managing the actual elements of a call.
400
SMB
Server Message Block
-enables file sharing, printer sharing, network browsing, and inter-process communication (through named pipes) over a computer network
400
SSL
Secure Sockets Layer
-communication protocol, or set of rules, that creates a secure connection between two devices or applications on a network
400
URL
Uniform Resource Locator
-a location or address identifying where documents can be found on the internet.
400
VIP
Virtual IP
- IP addresses that are not tethered to particular machines.
400
TKIP
Temporal Key Integrity Protocol
-encrypts each data packet with a unique encryption key.
400
TLS
Transport Layer Security
-encrypts data sent over the Internet to ensure that eavesdroppers and hackers are unable to see what you transmit
400
TX/RX
Transmit and Receive
401
TIA/EIA
Telecommunications Industry
Association/Electronic Industries Alliance
-
402
WDM
Wavelength Division Multiplexing
-increases bandwidth by allowing different data streams at different frequencies to be sent simultaneously over a single optical fiber network
