Mid-Term II Flashcards
Study guide for mid-term II
Difference between IPv4 and IPv6
- IPv4: 32-bit address; written in decimal form; allows for 3.4 billion addresses; 8 bits per octet; 192.168.1.1
- IPv6: 128-bit address; written in hexadecimal; allows 340 undecillion addresses; supports auto-configuration and built-in security; 16 bits per section; 0000:0000:0000:0000:0000:0000:0000:0001
Private IP ranges for IPv4
- Class A: 10.0.0.0 – 10.255.255.255
- Class B: 172.16.0.0 – 172.31.255.255
- Class C: 192.168.0.0 – 192.168.255.255
Who assigns public IP addresses
Internet Assigned Numbers Authority (IANA) distributes IP’s to Regional Internet Registries (RIR) that then distribute IP’s within their assigned region.
What are the CIDR classes
- Class A: 1.0.0.0 - 126.255.255.255; Default mask - 255.0.0.0 (/8)
- Loopback: 127.0.0.1 - 127.255.255.255
- Class B: 128.0.0.0 - 191.255.0.0; Default mask - 255.255.0.0 (/16)
- Class C: 192.0.0.0 - 223.255.255.255; Default mask - 255.255.255.0 (/24)
- Class D: 224.0.0.0 - 239.255.255.255; Multicast Class
- Class E: 240.0.0.0-255.255.255.255; Reserved
Usable hosts on /30 subnet
Total: 4
Usable: 2
Usable hosts on /29 subnet
Total: 8
Usable: 6
Usable hosts on /28 subnet
Total: 16
Usable: 14
Usable hosts on /27 subnet
Total: 32
Useable: 30
Usable hosts on /26 subnet
Total: 64
Useable: 62
Usable hosts on /16 subnet
Total: 65,536
Usable: 65,534
Three main categories of ports
Well-Known (0-1023) - Assigned by IANA
Registered Ports (1024-49151) - Used by software vendors for proprietary applications
Dynamic/Ephemeral (49152-65535) - Temporarily used for client-side comms
What port does FTP (Data) use
Port 20
What port does FTP (Control) use
Port 21
What port does SSH use
Port 22
What port does Telnet use
Port 23
What port does SMTP use
Port 25
What port does DNS use
Port 53
What port does DHCP use
Port 67-68
What port does TFTP use
Port 69
What port does HTTP
Port 80
What port does POP3 use
Port 110
What port does NTP use
Port 123
What port does RPC use
Port 135
What port does NetBIOS use
Port 137-139
What port does IMAP use
Port 143
What port does SNMP use
Port 161-162
What port does LDAP use
Port 389
What port does HTTPS use
Port 443
What port does SMB/CIFS
Port 445
What port does Syslog use
Port 514
What port does IMAPS use
Port 993
What port does POP3S use
Port 995
What port does MS SQL use
Port 1433
What port does Oracle DB use
Port 1521
What port does L2TP use
Port 1701
What port does RADIUS use
Port 1812-1813
What port does MySQL use
Port 3306
What port does RDP use
Port 3389
What port does SIP use
Port 5060/5061
What port does BitTorrent use
51413
Which category of Ethernet cable supports speeds up to 10 Gbps?
CAT6a
True or False: Coaxial cables are commonly used for broadband Internet connections.
True
What is the maximum length for a standard Ethernet cable run?
100 meters
Which type of network cable is best for outdoor use?
Fiber optic cable
What type of connector is commonly used with Ethernet cables?
RJ45
What is the main advantage of fiber optic cables over copper cables?
Higher bandwidth and longer distance capabilities.
Fill in the blank: __________ cables use light to transmit data.
Fiber optic
What does the ‘U/FTP’ in cable specifications stand for?
Unshielded Foiled Twisted Pair
What is the typical color coding for Ethernet cables?
Orange and white stripes, blue and white stripes, green and white stripes, brown and white stripes.
True or False: Shielded cables are used to reduce electromagnetic interference.
True
What is the difference between single-mode and multi-mode fiber cables?
Single-mode fibers allow one light mode to propagate, while multi-mode fibers allow multiple light modes.
Fill in the blank: The standard for Ethernet networking is defined by __________.
IEEE 802.3
What is the maximum data transfer rate of CAT5e cables?
1 Gbps
Multiple Choice: Which type of cable is typically used for connecting a modem to a router? A) Coaxial B) Fiber C) Ethernet D) Telephone
C) Ethernet
True or False: Twisted pair cables are used in telephone networks.
True
What type of network cable is most resistant to physical damage?
Fiber optic cable
Fill in the blank: __________ cables are used for long-distance telecommunications.
Fiber optic
What does the term ‘crosstalk’ refer to in network cables?
Interference caused by signals in adjacent wires.
Multiple Choice: Which cable type is best for high-speed networks? A) CAT5 B) CAT6 C) CAT3 D) Coaxial
B) CAT6
What is the primary disadvantage of using copper cables?
Limited distance and susceptibility to interference.
True or False: Network cables can be used to power devices using Power over Ethernet (PoE).
True
Fill in the blank: The __________ cable is commonly used for connecting televisions to satellite dishes.
Coaxial
What is the main function of a patch cable?
To connect devices to a network switch or router.
True or False: The higher the category number of an Ethernet cable, the better its performance.
True
Fill in the blank: __________ cables are more flexible and easier to install than solid cables.
Stranded
What does the term ‘attenuation’ mean in the context of network cables?
Loss of signal strength over distance.
Multiple Choice: Which type of fiber optic cable is typically used for short distances? A) Single-mode B) Multi-mode C) Coaxial D) Twisted pair
B) Multi-mode
What is the primary use of a crossover cable?
To connect two like devices directly, such as two computers.
True or False: The maximum data rate of CAT6 cables is 10 Gbps.
True
Fill in the blank: The __________ connector is used with fiber optic cables.
Lucent Connector (LC)
What is the primary benefit of using shielded twisted pair (STP) cables?
Reduced electromagnetic interference.
What is the standard color for the wiring in a CAT5 cable?
Blue, orange, green, brown.
Fill in the blank: __________ cables are often used in data centers for high-speed connections.
Fiber optic
What is the main disadvantage of fiber optic cables?
Higher installation costs compared to copper cables.
Multiple Choice: Which of the following is NOT a characteristic of coaxial cables? A) High bandwidth B) Susceptible to interference C) Used for cable TV D) Used for long-distance networking
B) Susceptible to interference
What is the purpose of a network cable tester?
To check the integrity and performance of network cables.
True or False: Fiber optic cables are immune to electromagnetic interference.
True
This mode accommodates transmitting and receiving on the network, but not at the same time
Half-duplex mode
This mode simultaneously transmits and receives
Full-duplex mode
This type of cable is typically used with Fast Ethernet operating at 100Mbps with a transmission range of 100 meters
Category 5
This type of cable used on networks that run at 10/100Mbps and even up to 1000Mbps
Category 5e
This type of cable has a minimum of 250MHz of bandwidth and specifies cable lengths up to 100 meters with 10/100/1000Mbps transfer, along with 10Gbps over shorter distances
Category 6
This type of cable a minimum of 500MHz of bandwidth with transmission distance up to 100 meters with 10Gbps networking speeds
Category 6a
What type of coaxial cable is often used for cable TV and cable modems
RG-6
This type of fiber optic cable has many beams of light travel through the cable bouncing off the cable walls. This strategy actually weakens the signal reducing the length and speed at which the data signal can travel
Multi mode fiber
This type of fiber optic cable uses a single direct beam of light thus allowing for greater distances and increase transfers speeds
Single-mode fiber
This is the mysterious space that resides between the false, or drop, ceiling and the true ceiling
Plenum
This type of cable must be fire resistant and they must not produce toxic fumes if exposed to intense heat
Plenum cables
This type of fiber connector uses a half twist bayonet type of lock
Straight Tip (ST) connector
This type of fiber connector uses a push pull connector similar to common audio and video plugs and sockets
Subscriber Connector (SC) connector
This type of fiber connector has a flange on top similar to an RJ-45 connector that aids secure connection
Lucent Connector (LC) connector
This type of fiber connector is a popular connector for two fibers in a very small form factor
MT-RJ
This type of cable is proprietary cable used to connect a PC to a Cisco router
Rollover cable
This type of cable is used to test and isolate network problems
Loopback cable
This type of cabling connects the telecommunication room to the end-user
Horizontal cabling
This type of cabling connects telecommunication rooms, server rooms, and remote locations and offices
Vertical cables
This provides a connection point between network equipment such as hubs and switches and the ports to which PCs are connected which normally are distributed throughout a building
Patch panels
This type of closet for a network typically holds the majority of the network gear including routers switches wiring servers and more. This is also typically the wiring closet where outside lines run into the network
Main Distribution Frame (MDF)
This is the connection point between the operators part of the network and the customers portion of the network
Demarc
This standard defines a range of networking systems based on the original ethernet standard
802.3
This, which is defined in the IEEE 802.3 standard, is the most common media access method because it is associated with 802.3 Ethernet networking, which is by far the most popular networking system
Carrier Sense Multiple Access/Collision Detection CSMA/CD
This is known as a contention media access method because systems contend for access to the media
CSMA/CD
On a network that uses this, every node has equal access to the network media
CSMA/CD
On this type of network, each computer signals its intent to transmit data signals before any data is actually sent
Carrier Sense Multiple Access/Collision Avoidance CSMA/CA
CSMA/CA uses this method to signal its intention to transmit data
Broadcasts
This enables you to use multiple channels at the same time to increase performance
Bonding
10BaseT ethernet type has
Speed: 10 Mbps
Medium: Twisted Pair (Cat3 or better)
Max Length: 100 meters
100BaseTX ethernet type has
Speed: 100 Mbps
Cable Type: Twisted pair (Cat5 or higher)
Max Length: 100 meters
1000BaseT ethernet type has
Speed: 1 Gbps
Cable Type: Twisted pair (Cat5e or higher)
Max Length: 100 meters
10GBaseT ethernet type has
Speed: 10 Gbps
Cable Type: Twisted pair (Cat6a or higher)
Max Length: 100 meters
100Base-FX ethernet type has
Speed: 100 Mbps
Cable Type: Fiber optic
Max Length: 2 kilometers (multi-mode fiber)
1000BaseLX
Speed: 1 Gbps
Cable Type: Fiber optic
Max Length: 5 kilometers (single-mode fiber)
10GBaseSR
Speed: 10 Gbps
Cable Type: Fiber optic
Max Length: 300 meters (multi-mode fiber)
Common Ethernet Suffixes
T: Twisted Pair (e.g., 100Base-TX)
TX: Twisted Pair with extended capabilities (e.g., 100Base-TX)
FX: Fiber Optic (e.g., 100Base-FX)
LX: Long Wavelength Fiber Optic (e.g., 1000Base-LX)
SX: Short Wavelength Fiber Optic (e.g., 1000Base-SX)
SR: Short Range Fiber Optic (e.g., 10GBase-SR)
LR: Long Range Fiber Optic (e.g., 10GBase-LR)
10 Gigabit Ethernet is defined in what IEEE standard
802.3ae
What is 802.11a?
Frequency: 5 GHz
Speed: Up to 54 Mbps
This is the maximum possible speed under perfect conditions (no interference, ideal distance, etc.)
Range: Shorter than 2.4 GHz (higher freq = less penetration)
Often used in business or industrial environments
What is 802.11b
Frequency: 2.4 GHz
Speed: Up to 11 Mbps
Range: Good range, but very susceptible to interference from devices like microwaves and Bluetooth
Obsolete but foundational
What is 802.11g
Frequency: 2.4 GHz
Speed: Up to 54 Mbps
Backward compatible with 802.11b
Suffers from the same interference as 802.11b
What is 802.11n
Frequency: 2.4 GHz and 5 GHz (dual-band)
Speed: Supports speeds up to 600 Mbps (theoretical), but commonly seen at up to 540 Mbps or slightly lower in practice. (typically 150–300 Mbps per channel)
Uses MIMO (Multiple Input Multiple Output)
Backward compatible with a/b/g
What is 802.11ac
Frequency: 5 GHz
Speed: Up to 6.9 Gbps
Uses MU-MIMO and wider channels (80/160 MHz)
Backward compatible with 802.11n
What is 802.11ax
requency: 2.4 GHz & 5 GHz, newer variants support 6 GHz
Speed: Up to 9.6 Gbps total throughput
More efficient for high-density environments (stadiums, offices)
Introduces OFDMA and Target Wake Time (TWT)
What is WEP
Wired Equivalent Privacy
Uses RC4 stream cipher
Very insecure due to weak key generation
Deprecated; should not be used
What is WPA
Wi-Fi Protected Access
Uses TKIP (Temporal Key Integrity Protocol)
Introduced to replace WEP
Better than WEP, but still has vulnerabilities
What is WPA2
Replaces TKIP with AES encryption (CCMP mode)
Much more secure than WPA
Recommended minimum for secure networks
What is WPA3
Latest Wi-Fi security standard
Uses SAE (Simultaneous Authentication of Equals) for stronger handshakes
Better protection against dictionary attacks
Individualized data encryption
What is omni directional antenna
Sends/receives signals in all directions equally
Ideal for general coverage in open spaces
Common in home routers
What is a Yagi antenna
Highly directional antenna
Long-range, focused beam
Great for point-to-point communication (e.g., between buildings)
What is a panel antenna
Flat and directional
Mounts on walls to focus signal
Offer a directional radiation pattern, which means they focus the signal in one direction, ideal for point-to-point connections (like between buildings)
Easier to install and align than larger directional options like parabolic antennas
Less likely to interfere with nearby 4G/5G signals since the radiation pattern is focused
What is a parabolic antenna
Uses a dish to focus signals
Very long-range, extremely directional
Often used for satellite or long-distance point-to-point Wi-Fi
What is SSID broadcast
The SSID is the network name broadcast by the AP
Disabling SSID broadcast hides the network from casual scanning, but doesn’t provide real security
What is RADIUS
Remote Authentication Dial-In User Service
Centralized AAA (Authentication, Authorization, Accounting) service
Used in WPA2-Enterprise and WPA3-Enterprise
Integrates with Active Directory or LDAP for user authentication
What is static routing
Routing paths are manually configured by a network administrator.
Used in small networks or for predictable routing needs.
Advantages: Simple, secure, no overhead.
Disadvantages: Doesn’t adapt to changes or failures.
What is dynamic routing
Routers automatically share routing information using protocols.
Adapts to network changes (e.g., down links or new routes).
Involves routing algorithms and metrics (like hop count, bandwidth, delay).
What is RIP
Routing Information Protocol
Distance-vector routing protocol
Uses hop count as metric (max 15 hops)
Simple but slow to converge and not scalable
RIPv1: Classful (no subnet info)
RIPv2: Classless, supports VLSM
What is OSPF
Open Shortest Path First
Link-state routing protocol
Uses cost (based on bandwidth) as metric
Fast convergence, highly scalable
Supports VLSM and CIDR
Common in enterprise environments
What is BGP
Border Gateway Protocol
Path-vector protocol used on the Internet
Used for routing between autonomous systems (ASes)
Complex and policy-based routing decisions
Essential for ISPs and large-scale networks
What is EIGRP
Enhanced Interior Gateway Routing Protocol (Cisco proprietary)
Hybrid protocol (both distance-vector and link-state features)
Uses DUAL algorithm
Metric based on bandwidth, delay, reliability, and load
Faster convergence and more efficient than RIP
What is VLAN
Virtual Local Area Network
Logically segments a network into separate broadcast domains, even if devices are on the same switch
Improves security, performance, and management
What is 802.1q
IEEE standard for VLAN trunking
Adds a VLAN tag to Ethernet frames to carry VLAN info across switches
Enables multiple VLANs to be transported over a single trunk link
What is a trunk port
A switch port configured to carry multiple VLANs
Used between switches or to VLAN-aware devices (like routers/firewalls)
What is an access port
A switch port assigned to a single VLAN
Used to connect end-user devices like PCs
What is an Access Control Lists (ACL)
A set of rules used to permit or deny traffic based on IP, protocol, or port
Can be applied inbound or outbound on a router interface
Used for filtering, firewalling, and traffic control
What are the two main types of ACLs
Standard ACL: Filters by source IP address only
Extended ACL: Filters by source/destination IP, protocol, and port numbers
What is Spanning Tree Protocol (STP)
What is STP and why is it important?
A:
Spanning Tree Protocol (802.1D) prevents switching loops in Layer 2 networks
Automatically blocks redundant paths while keeping backup links available
Elects a Root Bridge and calculates the shortest path tree
What are some improvements to Spanning Tree Protocol (STP)
RSTP (802.1w): Rapid Spanning Tree – faster convergence
MSTP (802.1s): Multiple Spanning Tree Protocol – supports multiple STP instances for VLANs
Open Systems Interconnection (OSI) Model
The Open Systems Interconnection (OSI) model is a conceptual framework used to understand and standardize how different networking protocols interact in a layered architecture.
Consists of 7 layers.
Open Systems Interconnection (OSI) Layer 7
Application Layer
Interfaces directly with user applications (e.g., browsers, email)
Protocols: HTTP, FTP, SMTP, POP3, IMAP, DNS
Open Systems Interconnection (OSI) Layer 6
Presentation Layer
Responsible for data format translation, encryption, and compression
Converts data into a format readable by the application layer
Open Systems Interconnection (OSI) Layer 5
Session Layer
Manages sessions and connections between computers
Responsible for establishing, maintaining, and terminating sessions
Open Systems Interconnection (OSI) Layer 4
Transport Layer
Responsible for reliable data transport
Protocols: TCP (reliable), UDP (unreliable)
Handles segmentation, flow control, and error recovery
Open Systems Interconnection (OSI) Layer 3
Network Layer
Handles logical addressing and routing
Protocols: IP, ICMP, ARP, RIP, OSPF, BGP
Breaks data into packets
Open Systems Interconnection (OSI) Layer 2
Data Link Layer
Responsible for MAC addressing, framing, and error detection
Sub-layers: LLC (Logical Link Control) and MAC (Media Access Control)
Protocols: Ethernet, PPP, HDLC
Open Systems Interconnection (OSI) Layer 1
Physical Layer
Defines the hardware and transmission of raw bits over a medium
Includes cables, NICs, hubs, modems, and signaling standards
Transmission Control Protocol/Internet Protocol (TCP/IP)
A 4-layer model used by modern networks and the Internet
More practical than OSI; directly maps to protocols in use
TCP/IP and OSI
Application (OSI Layers 5-7)
Transport (OSI Layer 4)
Internet (OSI Layer 3)
Network Interface (OSI Layers 1-2)
What does DOCSIS stand for?
Data Over Cable Service Interface Specification
What is DOCSIS used for?
A telecommunications standard used to deliver high-speed Internet over cable TV systems
Employed by cable internet providers
Developed by CableLabs
Supports data, voice, and video over existing coaxial cable infrastructure
What does POTS stand for and what is it?
Plain Old Telephone System
The basic analog voice service provided over copper telephone wires
Used in traditional landline systems
Works over the PSTN
What does DSL stand for?
Digital Subscriber Line
The installer failed to install the POTS filters on the phones.
DSL and voice share the same phone line.
POTS filters are required on each phone jack to prevent DSL signal interference with voice calls.
Without filters, phones may have no dial tone or experience static.
What does PTSN stand for
Public Switched Telephone Network
What is PSTN used for
The global network of traditional telephone lines (POTS)
Used to make voice calls across public and private networks
Supports analog voice transmission over copper wires
What is V.90?
A ITU-T standard for dial-up modems
It defines a maximum download of 56 Kbps over analog phone lines
Upload speeds were typically 33.6Kbps
What channels are available for 2.4 GHz
1, 6, 11
What is LDAP
LDAP = Lightweight Directory Access Protocol
Used to query and modify directory services (like Active Directory)
Often works with RADIUS as the backend directory storing user credentials
Not directly used by WPA2-Enterprise, but supports it indirectly
What is TFTP
Trivial File Transfer Protocol
A simple, lightweight file transfer protocol
Used for tasks like:
Transferring router/switch configs
Uploading firmware to network devices
Not secure, and not used for wireless authentication
What is IPSec
Internet Protocol Security
A suite of protocols for securing IP traffic
Commonly used in VPNs to encrypt data between endpoints
Works at the network layer, providing confidentiality, integrity, and authentication
Not used for Wi-Fi encryption like WPA2
What is PKI
Public Key Infrastructure
Manages X.509 digital certificates
Enables secure authentication, encryption, and digital signatures
Used for VPNs, Wi-Fi (WPA2-Enterprise), web security (HTTPS)
Core of certificate-based authentication
What is Kerberos
Network authentication protocol using tickets, not certificates
Used in Windows domain environments (Active Directory)
Provides mutual authentication and single sign-on (SSO)
Does not use X.509 certificates
What is TACACS+
Terminal Access Controller Access-Control System Plus
Used to authenticate access to network devices (e.g., routers, switches)
Separates authentication, authorization, and accounting
Does not use or manage X.509 certificates
What are X.509 Certificates
X.509 certificates are digital certificates that follow the X.509 standard for public key infrastructure (PKI). They’re used to prove someone’s identity online and enable secure communication.
What do X.509 Certificates include?
Subject Name (who the certificate belongs to — a user, website, or device)
Issuer (who issued the certificate — e.g., a Certificate Authority)
Public Key (used to encrypt or verify data)
Valid From / To (expiration and start dates)
Serial Number (unique ID for the cert)
Digital Signature (proves the certificate hasn’t been tampered with)
What are X.509 Certificates used for?
Secure Websites (HTTPS)
The padlock icon in your browser? That’s made possible by an X.509 certificate.
User or Device Authentication
Used in WPA2-Enterprise, VPNs, and smart card logins.
Secure Emails
Enables email encryption and digital signatures (e.g., S/MIME).
Code Signing
Verifies the integrity and origin of software.
What is TKIP and where is it used?
Temporal Key Integrity Protocol
Used in WPA (Wi-Fi Protected Access)
Designed as a quick fix for weaknesses in WEP
Provides per-packet key changes for improved security
Compatible with older (legacy) devices
Used in WPA Mixed Mode alongside AES
What is AES and where is it used in WIRELESS networks?
Advanced Encryption Standard
Used in WPA2 for strong wireless encryption
Provides robust, modern encryption
Not backward-compatible with legacy WPA-only devices
Used in WPA Mixed Mode alongside TKIP to support newer devices
What is TEMPEST, and what is it used for?
TEMPEST is a U.S. government standard for shielding electronic equipment from leaking sensitive information via radio frequency (RF) emissions.
Prevents electronic snooping or eavesdropping on secure communications
Used in military, government, and high-security environments
Involves shielding, grounding, and device design to limit signal leakage
What is DWDM, and what does it do?
Dense Wavelength Division Multiplexing
A technology used in fiber-optic networks
Combines multiple data signals on a single fiber by using different light wavelengths
Greatly increases bandwidth and efficiency in long-distance data transmission
Common in telecom backbones and large-scale ISPs
What is a public cloud?
Services are delivered over the internet
Managed by a third-party provider (e.g., AWS, Microsoft Azure, Google Cloud)
Shared resources among multiple customers
Scalable, cost-effective, and quick to deploy
Example use: Hosting websites, cloud storage, SaaS
What is a Private Cloud
Cloud infrastructure is used exclusively by one organization
Can be hosted on-premises or by a third party
Offers greater control, security, and customization
Ideal for industries with strict regulatory requirements (e.g., healthcare, finance)
What is a hybrid cloud?
Combines private cloud + public cloud
Enables data and application portability between environments
Great for scalability during peak usage or disaster recovery
Example: Internal systems + temporary cloud servers for added capacity
What is a community cloud?
Shared by multiple organizations with common goals or compliance needs
Managed internally or by a third party
Balances cost savings and customization
Example: Government agencies or universities sharing infrastructure
What is SaaS
Software as a Service
Delivers fully functional applications over the internet
Users access the software via a web browser; no local installation required
The provider manages everything: application, data, OS, infrastructure
Examples: Google Workspace, Microsoft 365, Salesforce, Dropbox
What is PaaS
Platform as a Service
Provides a development and deployment environment in the cloud
Developers use it to build, test, and deploy applications
Users manage: Apps and data
Provider manages: OS, runtime, servers, storage, infrastructure
Examples: Google App Engine, Heroku, Microsoft Azure App Services
What is IaaS
Infrastructure as a Service
Provides virtualized computing resources over the internet
Users manage: Operating systems, applications, storage
Provider manages: Servers, networking, virtualization, hardware
Offers flexibility and scalability
Examples: Amazon EC2, Microsoft Azure VM, Google Compute Engine
What is GSM
Global System for Mobile Communications
A 2G digital cellular network standard
Used worldwide (especially in Europe and Asia)
Supports voice, SMS, and basic data
Uses TDMA and SIM cards
Foundation for later technologies like EDGE and LTE
What is EDGE (not the browser)
Enhanced Data rates for GSM Evolution
Also called 2.75G
An enhancement of GSM networks to support faster data transfer
Max speed: ~384 Kbps
Often shown as “E” on phones when connected to a slower data network
What is LTE?
Long Term Evolution
A 4G wireless standard for high-speed data and voice
Offers speeds up to 100+ Mbps
Based on IP packet-switched technology
Common in smartphones and modern cellular networks
Transition toward VoLTE (Voice over LTE) and 5G
What is CDMA
Code Division Multiple Access
Competing standard to GSM (mainly used in the U.S. by Verizon/Sprint)
Does not use SIM cards (traditionally — newer CDMA phones now may)
Devices are tied to the network provider
Uses code-based multiplexing to separate users
Being phased out in favor of LTE/5G
What are the benefits of caching on a Web proxy?
Response Time
Virus Detection
What is a Web Proxy
is an intermediary server that sits between a user’s device and the internet. It processes requests from the user and forwards them to the destination server, then returns the response to the user.
What is SLAAC and what does it stand for?
Stateless Address Autoconfiguration
To allow a host to automatically configure its own IPv6 address without the need for a DHCP server
What does WINS stand for and what does it do?
Windows Internet Name Service
Resolves NetBIOS names to IP addresses
What protocol does WINS use to register and resolve NetBIOS names?
NetBIOS Name Service (NBNS)
When does a host register its NetBIOS name with the WINS server?
When does a host register its NetBIOS name with the WINS server?
What port does WINS/NetBIOS name service typically use?
UDP port 137
What does POP3 stand for?
Post Office Protocol v3W
What does IMAP4 stand for?
Internet Message Access Protocol v4
POP3 vs IMAP4
Pop3 - Downloads emails to a local device and deletes them from the server.
IMAP4 - Synchronizes emails with the server, allowing access from multiple devices.
What protocol does IPv6 use to discover neighbors and replace ARP?
NDP (Neighbor Discovery Protocol)
Remote workers, telecommuters, and traveling employees.
Purpose: Allows individual users to connect to a central network securely.
Requires: VPN client software on the user’s device.
Use Case: Remote work, secure access to internal company resources from home or on the go.
Site-to-Site VPN
Purpose: Connects two or more entire networks (sites) together.
Requires: Routers/firewalls with VPN capabilities—no client software on user devices.
Use Case: Linking branch offices to a main office securely over the internet.
DMVPN (Dynamic Multipoint VPN)
Purpose: A Cisco-developed enhancement of Site-to-Site VPNs allowing dynamic, direct tunnels between sites.
Requires: Cisco routers, uses mGRE and NHRP for scalability.
Use Case: Large-scale, meshed networks where branch offices can connect to each other dynamically.
MPLS VPN (Multiprotocol Label Switching VPN)
Purpose: A service provider-managed VPN that uses label switching rather than traditional routing.
Requires: ISP infrastructure support—typically used by businesses, not home users.
Use Case: High-performance, scalable connections between enterprise sites—often faster and more reliable than internet-based VPNs.
Extranet VPN
Purpose: Connects a company’s network to that of a partner, vendor, or customer over a secure VPN.
Requires: Similar to Site-to-Site, usually built between two organizations.
Use Case: Secure communication between business partners.
What does the dig command do in Linux/macOS? What does it stand for?
Performs DNS lookups and displays detailed results such as: IP address, DNS record type, TTL, query time, and name server info.
Domain Information Groper
What is ICMP and what does it stand for?
ICMP operates at layer 3 of the OSI model. It sends error messages and operational information about network conditions.
Internet Control Message Protocol
What does a firewall do?
A firewall is a security device or software that controls incoming and outgoing network traffic based on a set of configured rules.
It is commonly placed at the network edge (perimeter) to protect internal networks from unauthorized access and filter traffic based on IP addresses, ports, and protocols.
Which DNS record type maps a hostname to an IPv6 address?
A DNS AAAA record (pronounced “quad-A”) maps a hostname to an IPv6 address.
It is the IPv6 equivalent of an A record, which maps to an IPv4 address.
What is geofencing in the context of mobile device management (MDM)?
It involves setting up virtual geographic boundaries using GPS, Wi-Fi, RFID, or cellular data.
When a managed device enters or leaves one of these boundaries, automated actions can be triggered. Examples include:
Restricting app access
Enforcing specific security policies
Sending alerts to administrators
What technique enables IPv6 packets to travel over an IPv4-only network?
Tunneling (e.g., 6to4, Teredo, ISATAP)
Which IPv6 tunneling method uses a public IPv4 address to automatically generate an IPv6 address?
6to4
It requires a public IPv4 address and is not NAT-friendly.
Which IPv6 tunneling technique is specifically designed to work through NAT?
Teredo
Which tunneling method is typically used within enterprise networks over internal IPv4 infrastructure?
ISATAP (Intra-Site Automatic Tunnel Addressing Protocol)
Which general-purpose tunnel can encapsulate any Layer 3 protocol, including IPv6 over IPv4?
GRE (Generic Routing Encapsulation)
What are the US and EU fiber optic transmission standards?
US: SONET (Synchronous Optical Network)
EU: SDH (Synchronous DIgital Hierarchy)
What is MX
MX (Mail Exchange) records in DNS specify which mail servers are responsible for receiving email on behalf of a domain.
They include:
Priority values (lower = higher priority)
Hostnames of the mail servers (not IP addresses directly)
What is the approximate data rate of a T1 line?
~1.544 Mbps
How many channels are in a T1 line?
24 channels, each 64Kbps
What is the purpose of Administrative Distance (AD) in routing
To determine the trustworthiness or preference of a routing source.
Lower distance = More trusted
What does a CNAME record represent in DNS
CNAME (Canonical Name) record in DNS is used to map an alias name to the real (canonical) domain name.
What does IEEE 802.1X standard define and what is it used for?
Port-Based Network Access Control (PNAC)
It is used to authenticate devices before they are granted access to the network.
Commonly used in:
Wired networks (e.g., switch ports)
Wireless networks (e.g., enterprise Wi-Fi)
What is the first thing to check when troubleshooting DNS on a client machine?
When troubleshooting DNS issues on a client machine, the first thing to check is whether the correct DNS server addresses are configured.
PPTP VPN
It was used for legacy remote access, mainly for individual users
Not secure by modern standards
L2TP VPN
Layer 2 Tunneling Protocol
L2TP with IPsec
It adds encryption and security to an otherwise non-secure tunneling protocol.
What command is commonly used on Cisco routers to enter global configuration mode?
configure terminal
What command is used to enter privileged EXEC mode from user EXEC mode?
enable
What command displays the currently running configuration?
show running-config
What command sets a static route on a router?
ip route [destination] [subnet mask] [next hop IP/interface]
What command is used to configure a specific interface?
interface [type/number]
What command sets a password for privileged EXEC mode?
enable secret [password]
What command enables an interface?
no shutdown
What command disables an interface?
shutdown
What command shows the routing table?
show ip route
What command shows interface status and statistics?
show interfaces or show ip interface briefWhat command is used to test IP connectivity?
What command is used to test IP connectivity?
ping [destination IP]
What command is used to trace the path to a destination?
traceroute [destination IP]
What is the bandwidth of a T3 line?
44.736 Mbps
Combines 28 T1 lines, totaling 672 voice/data channels.
What are the two main types of dynamic routing protocols?
Distance Vector and Link-State
What type of routing protocol is OSPF?
Link-State
What algorithm does OSPF use to determine the best path?
Dijkstra’s Shortest Path First (SPF) algorithm
What protocol uses hop count as its primary metric?
RIP (Routing Information Protocol)
Max hop limit: 15; 16 = unreachable
Which protocol is a hybrid routing protocol developed by Cisco?
Combines features of both distance vector and link-state
What protocol is used for routing between autonomous systems on the Internet?
BGP (Border Gateway Protocol)
What are common metrics used by routing protocols?
Hop count (RIP)
Cost (OSPF)
Bandwidth, delay (EIGRP)
AS Path, Policy (BGP)
