Brief Summary
This video provides a comprehensive review for the CompTIA Network Plus N10-009 certification exam, covering networking concepts, implementation, operations, security, and troubleshooting. It includes practice questions and explanations, focusing on key exam objectives and acronyms.
- OSI Model Layers
- Networking Devices and Functions
- Wireless Technologies
- Cloud Computing Concepts
- Network Security
- Network Troubleshooting
Networking Concepts: OSI Model and Network Devices
The OSI model's layer 1 (Physical) defines data encoding, transmission, and reception over physical media. Layer 2 (Data Link) handles error detection, correction, and physical addressing. Layer 3 (Network) is responsible for IP addressing and packet routing. Layer 4 (Transport) ensures reliable data delivery and manages flow control. Layer 5 (Session) maintains communication sessions between applications. Layer 6 (Presentation) handles encryption, compression, and data format translation. Layer 7 (Application) provides network services to end-user applications. Routers forward data packets between different networks using IP addresses, while switches forward packets within the same network based on MAC addresses. Firewalls prevent unauthorized access by monitoring traffic based on security policies. Intrusion Detection Systems (IDS) detect and alert on potential security threats, while Intrusion Prevention Systems (IPS) detect and block threats in real-time.
Network Implementation: Load Balancers, Storage, and Wireless Technology
Load balancers distribute incoming network traffic across multiple servers to optimize resource usage. Proxies act as intermediaries between clients and servers, filtering content and providing anonymity. Network Attached Storage (NAS) provides centralized data access and file sharing over the network. Storage Area Networks (SAN) offer centralized high-speed storage access. Wireless technology enables communication without physical connections, and access points connect wired devices to wireless networks. Wireless controllers centrally manage multiple access points and devices. Applications in a network provide specific functionalities for end-users or devices. Content Delivery Networks (CDN) distribute content based on geographic location. Virtual Private Networks (VPN) enable secure connections between remote users and private networks. Quality of Service (QoS) prioritizes network traffic for critical applications.
Cloud Computing and Network Virtualization
Time to Live (TTL) represents the maximum number of hops a packet can traverse before being discarded. Network Functions Virtualization (NFV) virtualizes network infrastructure services to reduce hardware dependencies. Virtual Private Clouds (VPC) are private networks hosted within public cloud infrastructures. Network Security Groups define rules to allow or deny traffic to virtual machines. Network Security Lists define IP addresses allowed or denied access to cloud resources. Cloud gateways connect private networks to public clouds, while internet gateways allow communication between VPCs and the internet. NAT gateways allow multiple devices in a private network to share a single public IP address. Direct Connect provides dedicated high-speed connections between on-premises data centers and cloud providers.
Cloud Deployment Models and Services
Public clouds are hosted by third-party providers and shared among multiple customers. Private clouds are dedicated to a single organization and managed internally or by a third party. Hybrid cloud deployment combines private and public cloud features. Software as a Service (SaaS) offers complete software applications hosted by a third-party provider. Infrastructure as a Service (IaaS) offers virtualized computing resources like servers, storage, and networking. Platform as a Service (PaaS) offers a platform for developers to build, run, and deploy applications. Scalability is the ability to handle increased workload by adding more resources. Elasticity is the ability to automatically scale resources up or down based on demand. Multi-tenancy is the ability of a single instance of a cloud service to serve multiple customers with isolated resources.
Network Ports and Protocols
File Transfer Protocol (FTP) uses ports 20 and 21, while Secure File Transfer Protocol (SFTP) and Secure Shell (SSH) use port 22. Telnet uses port 23, and Simple Mail Transfer Protocol (SMTP) uses port 25. Domain Name System (DNS) uses port 53, and Dynamic Host Configuration Protocol (DHCP) uses ports 67 and 68. Trivial File Transfer Protocol (TFTP) uses port 69, and Hypertext Transfer Protocol (HTTP) uses port 80. Network Time Protocol (NTP) uses port 123, and Simple Network Management Protocol (SNMP) uses ports 161 and 162. Lightweight Directory Access Protocol (LDAP) uses port 389, and Hypertext Transfer Protocol Secure (HTTPS) uses port 443. Server Message Block (SMB) uses port 445, and Syslog uses port 514. Simple Mail Transfer Protocol Secure (SMTPS) uses port 587, and Lightweight Directory Access Protocol over SSL (LDAPS) uses port 636. SQL server uses port 1433, Remote Desktop Protocol (RDP) uses port 3389, and Session Initiation Protocol (SIP) uses ports 5060 and 5061.
Network Protocols and Encapsulation
Internet Control Message Protocol (ICMP) sends error messages and operational information about IP processing. Transmission Control Protocol (TCP) provides reliable, connection-oriented communication. User Datagram Protocol (UDP) is connectionless and provides faster communication without reliability checks. Generic Routing Encapsulation (GRE) encapsulates Layer 3 protocols for tunneling over IP networks. Internet Protocol Security (IPsec) provides secure IP communications by authenticating and encrypting each IP packet. Authentication Header (AH) provides integrity and authentication of data packets. Encapsulating Security Payload (ESP) provides data confidentiality, integrity, and authentication through encryption. Internet Key Exchange (IKE) establishes security associations and cryptographic keys used in IPsec communication.
Network Traffic Types and Wireless Standards
Unicast communication is data sent from one device to a specific single destination device. Multicast traffic is data sent from one device to multiple specific devices on the network. Anycast communication is data sent from one device to the nearest device in a group of possible destinations. Broadcast traffic is data sent from one device to all devices on a network segment. The 802.11 standard defines specifications for wireless local area networks (WLANs). Cellular networks provide high-speed data transfer without physical cables. Satellite communication enables communication in remote areas where wired networks are not feasible. The 802.3 standard defines specifications for Ethernet networks.
Cables and Connectors
Single-mode fiber supports longer transmission distances with a single light path, while multi-mode fiber uses multiple light paths for shorter distances. Direct Attach Copper (DAC) cables provide a low-cost, high-speed alternative to fiber optics for short-distance connections. Twin axial cables have two copper conductors inside a single shield, while coaxial cables have a single conductor. Coaxial cables have a metal shield that protects against interference. Cable speed ratings determine the maximum data transmission rate supported by a cable over a specific distance. Plenum cables are designed for use in air handling spaces and are made of fire-resistant materials. Transceivers convert signals between different types of networking mediums.
Network Topologies and Hierarchical Models
Ethernet protocol specifies how data is formatted into frames for transmission over a local area network. Fiber Channel provides high-speed communication between servers and storage devices in storage area networks. Small Form Factor Pluggable (SFP) transceivers provide a physical interface for transmitting high-speed data over fiber optic or copper cables. Quad SFP (QSFP) transceivers support higher data rates and multiple channels. Subscriber Connectors (SC) connect fiber optic cables to network devices with a secure push-pull mechanism. Local Connectors (LC) connect fiber optic cables to network devices with a small form factor for high-density applications. Straight Tip (ST) connectors provide a secure locking connection for fiber optic cables with a bayonet-style mechanism. Multi-fiber Push On (MPO) connectors provide high-density multi-fiber connections with a push-pull mechanism. RJ11 connectors are standard connectors used for telecommunication devices, while RJ45 connectors connect network devices to Ethernet cables. F-type connectors are coaxial cable connectors commonly used in cable television and internet applications. BNC connectors are coaxial cable connectors commonly used in networking and video transmission.
Network Design and Addressing
Mesh network topology connects all devices directly to each other, ensuring multiple paths for data transmission. Hybrid network topology combines multiple topologies to meet specific network needs. Star hub and spoke topology connects each device to a central hub. Spine and leaf network topology improves performance and scalability by connecting each leaf switch to every spine switch. Point-to-point network topology creates a direct connection between two devices. In a three-tier hierarchical model, the access layer provides access to the network and manages user devices, the core layer provides high-speed redundant connectivity between distribution switches, and the distribution layer handles routing and policy enforcement between different subnets and VLANs. A collapsed core network design combines the core and distribution layers into a single layer. North-south traffic flow is data flow between the client and the data center, while east-west traffic flow is data flow between devices within the same data center or network segment.
IP Addressing and SD-WAN
Automatic Private IP Addressing (APIPA) assigns private IP addresses to devices that cannot obtain an IP address from a DHCP server. RFC 1918 defines the range of private IP addresses that can be used in local networks. The loopback address in IPv4 is 127.0.0.1. Variable Length Subnet Masking (VLSM) allows network administrators to allocate IP addresses to different subnets based on need. Classless Inter-Domain Routing (CIDR) allows more efficient use of IP address space by using variable length subnet masks. Class A IP addresses range from 10.0.0.0 to 10.255.255.255, Class B ranges from 172.16.0.0 to 172.31.255.255, and Class C ranges from 192.168.0.0 to 192.168.255.255. Class D IP addresses are reserved for multicast communication, and Class E is reserved for experimental use. Application-aware SD-WAN dynamically adjusts the routing of data based on application performance and QoS requirements. Zero-touch provisioning allows network devices to be automatically configured with minimal manual intervention. Transport agnostic SD-WAN can use any type of underlying transport network. Central policy management in SD-WAN allows administrators to define and enforce network policies from a single central point.
Network Virtualization and Security
Virtual Extensible Local Area Network (VXLAN) extends Layer 2 network segments over Layer 3 networks. Data Center Interconnect (DCI) provides connectivity and communication between geographically separated data centers. SD-WAN typically uses Layer 2 encapsulation to ensure secure data transmission across networks. Zero Trust Architecture (ZTA) assumes no implicit trust and requires verification at every access point. Policy-based authentication makes network access decisions based on predefined policies. The principle of least privilege access ensures users only have the minimal level of access necessary. Secure Access Service Edge (SASE) combines networking and security into a unified cloud-delivered service. Security Service Edge (SSE) integrates security features into cloud-delivered services.
Infrastructure as Code and Network Automation
Infrastructure as Code (IaC) automates the process of managing and provisioning infrastructure through code. Playbooks, templates, and reusable tasks in IaC standardize infrastructure configurations. Configuration drift refers to changes that cause infrastructure configurations to deviate from their intended state and is managed by continuously enforcing the design. Upgrades in IaC improve the performance and security of the infrastructure through updated code and configurations. Dynamic inventory in IaC is a collection of real-time data about the infrastructure components used by automation. Source control in IaC tracks and manages changes to infrastructure code, ensuring version consistency. Version control in IaC allows teams to track changes, enabling rollbacks and collaboration. A central repository in IaC is a centralized location where infrastructure code and configuration files are stored and managed. Conflict identification in IaC detects and resolves discrepancies between different versions of infrastructure configurations. Branching in IaC creates parallel versions of the infrastructure code for testing and deployment without affecting the main configuration.
IPv6 Addressing and Routing Protocols
IPv6 mitigates the exhaustion of IPv4 addresses by providing a much larger address space. Tunneling is used to encapsulate IPv6 packets within IPv4 packets for transmission over IPv4 networks. A dual-stack configuration allows both IPv4 and IPv6 to operate on the same network. NAT64 enables communication between IPv6 and IPv4 networks by translating IPv6 packets into IPv4 packets. Static routing uses a predetermined path set by the network administrator, while dynamic routing automatically learns and updates routes based on current network conditions. Border Gateway Protocol (BGP) routes data between different autonomous systems on the internet. Enhanced Interior Gateway Routing Protocol (EIGRP) combines features of both link-state and distance vector routing protocols. Open Shortest Path First (OSPF) dynamically manages and maintains routing tables using a link-state protocol. Administrative distance is the preference value used to select the best route when multiple routes to the same destination exist. Prefix length represents the length of the network portion of an IP address expressed as a subnet mask. A metric in routing is a value that helps determine the best route by evaluating factors like distance, bandwidth, and delay.
Network Address Translation and Redundancy
Network Address Translation (NAT) translates private IP addresses into public IP addresses for routing across the internet. Port Address Translation (PAT) uses a single public IP address for multiple devices, differentiated by port numbers. First Hop Redundancy Protocol (FHRP) provides redundant IP addresses for a network to ensure continuous availability in case of router failure. A virtual IP (VIP) is an IP address used by multiple devices to share resources or services. A sub-interface is a virtual interface created on a physical interface to support multiple logical networks. A Virtual Local Area Network (VLAN) segments a network into smaller isolated networks. The VLAN database of a network switch stores a list of VLANs configured on the switch along with their corresponding ports. A switch virtual interface (SVI) provides a logical interface for routing between VLANs within a switch. A native VLAN carries untagged traffic on trunk ports. A voice VLAN separates voice traffic from data traffic.
VLAN Configuration and Network Cabling
802.1Q tagging adds a tag to Ethernet frames to indicate the VLAN membership of the traffic. Link aggregation combines multiple physical links into a single logical connection to increase bandwidth and redundancy. Speed in interface configuration is the rate at which data can be transmitted over a network link. Duplex refers to the ability to send and receive data on a network link simultaneously (full duplex) or one direction at a time (half duplex). Spanning Tree Protocol (STP) ensures there are no loops in a switch network by blocking redundant paths. Maximum Transmission Unit (MTU) is the largest size of a data packet that can be transmitted over a network without fragmentation. Jumbo frames are large Ethernet frames that allow for greater payloads. Channel width in wireless networking is the amount of frequency spectrum allocated for communication on a wireless channel. Non-overlapping channels in wireless networking reduce interference. Regulatory requirements define the allowed frequency ranges and power levels for wireless communication.
Wireless Networking and Security
The 802.11h standard provides enhancements for wireless network performance, including dynamic frequency selection (DFS) and transmit power control (TPC). The 2.4 GHz frequency band provides better range but is more susceptible to interference. The 5 GHz frequency band has a shorter range but offers less interference and higher data transmission speeds. The 6 GHz frequency band offers faster speeds and less congestion but has a shorter range. Band steering automatically directs dual-band devices to the 5 GHz band. Service Set Identifier (SSID) is a unique identifier for a wireless network. Basic Service Set Identifier (BSSID) is a unique identifier assigned to each wireless access point. Extended Service Set Identifier (ESSID) is the identifier used for multiple access points working together to form a larger wireless network.
Network Topologies and Wireless Security Protocols
A mesh network connects all devices directly to each other, ensuring redundancy and reliability. An ad hoc network is where devices connect directly to each other without a central access point. A point-to-point network is a direct connection between two devices. An infrastructure network includes a wireless access point or router that connects devices to the internet. Wi-Fi Protected Access 2 (WPA2) provides stronger encryption and better security for wireless networks using AES encryption. WPA3 provides stronger encryption, improved key exchange, and protection against offline dictionary attacks. A captive portal in a guest network provides a secure login page for users before accessing the internet. Pre-shared key (PSK) uses a shared password for all devices, while enterprise authentication uses individual credentials for each user.
Antennas, Network Equipment, and Cabling
An omnidirectional antenna broadcasts a signal in all directions, while a directional antenna focuses a signal in a specific direction. An autonomous access point operates independently with its own configuration, while a lightweight access point relies on a centralized controller. Locations for network equipment should be easily accessible for maintenance and monitoring while providing adequate space for airflow. An intermediate distribution frame (IDF) connects network cables from the main distribution frame (MDF) to individual devices within a building. The MDF serves as the central point where all network cables from various IDFs are connected and routed. Rack size should accommodate all current and future devices while providing adequate space for cooling and cable management. Port-side exhaust or intake is important to ensure proper airflow and prevent overheating. Cabling ensures reliable high-speed data transmission between network devices while minimizing interference.
Network Documentation and Management
A patch panel organizes and manages incoming and outgoing network cables in a central location. A fiber distribution panel manages and organizes fiber optic cables. Network equipment racks need to be lockable to prevent unauthorized physical access. An uninterruptible power supply (UPS) provides a temporary power source in case of power failure. A power distribution unit (PDU) distributes electrical power to multiple devices within a rack or data center. Power load refers to the amount of electrical current used by network devices. Voltage regulation ensures devices receive a stable and consistent power supply. Excessive humidity can cause corrosion of electrical components. Fire suppression is critical to prevent damage from electrical fires. The ideal temperature range for most network equipment is between 60°F and 75°F.
Network Diagrams and Inventory
Physical network diagrams show the layout of network devices and cables, while logical diagrams show how data flows and is routed. Rack diagrams show the physical arrangement of devices within server racks. Cable maps provide detailed information on the connections between devices, including cable types and lengths. Layer 1 diagrams show physical connections, Layer 2 diagrams show data link layer protocols, and Layer 3 diagrams show routing information. An asset inventory tracks hardware, software licenses, and warranty support for network equipment. IP address management (IPAM) allocates, manages, and tracks IP addresses within the network. A service level agreement (SLA) defines the expected performance and availability standards between service providers and clients. A wireless survey or heat map shows the signal strength and coverage area of wireless networks.
Network Equipment Lifecycle and Management Protocols
End of life (EOL) is the point at which the manufacturer stops selling and providing updates for a product. End of support (EOS) is the point at which the manufacturer stops providing technical support, updates, or patches for a product. Applying patches and bug fixes resolves software bugs, improves functionality, and closes security vulnerabilities. Updating an operating system improves security, adds new features, and fixes vulnerabilities. Firmware updates enhance device functionality, improve security, and fix bugs in the device's underlying software. Decommissioning network equipment entails safely removing equipment from service and ensuring it's securely disposed of or recycled. Request process tracking and change management ensure all change requests are documented, tracked, and properly reviewed before implementation. Production configuration defines the current working configuration of network devices and systems used in the production environment. Backup configuration stores an identical configuration to be used in case of failure. Baseline or golden configuration creates a reference configuration that defines the ideal or approved state of network devices.
Network Monitoring and Security
SNMP traps notify network administrators about specific events or conditions in devices. A Management Information Base (MIB) contains information about network devices' configuration and status. SNMP v3 introduced encryption for securing communication. SNMP v2c improves speed and efficiency by introducing community strings. The SNMP community string functions as a password to authenticate SNMP requests. SNMP authentication ensures only authorized users can access and manage SNMP-enabled devices. Flow data in network monitoring represents metadata associated with network traffic. Packet capture analyzes packets being transmitted on the network to diagnose issues. Baseline metrics are standard performance measurements used to compare network performance over time. Anomaly alerting detects and notifies administrators of unusual network activity. Log aggregation collects logs from multiple network devices and centralizes them for easier analysis. A Syslog collector collects and stores log data from network devices. Security Information and Event Management (SIEM) aggregates, analyzes, and correlates security events to detect and respond to threats. API integration allows different network management tools to interact and share data. Port mirroring copies network traffic from one port to another for monitoring and analysis.
Network Troubleshooting and Security Concepts
Network discovery identifies and maps devices and services running on a network. Ad hoc discovery is performed on demand, while scheduled discovery runs at regular intervals. Traffic analysis examines network traffic patterns to identify performance issues, bottlenecks, or security threats. Performance monitoring tracks network performance metrics to ensure the network runs efficiently. Availability monitoring ensures network services are continuously available by detecting outages and performance degradation. Configuration monitoring tracks changes in network configurations to ensure devices and systems remain properly configured and secure. Recovery Point Objective (RPO) represents the maximum acceptable amount of data loss. Recovery Time Objective (RTO) is the maximum allowable time for restoring services after a disaster. Mean Time to Repair (MTTR) measures the average time it takes to repair a device or restore a service after a failure. Mean Time Between Failures (MTBF) represents the average time between two failures of a system or device.
Disaster Recovery and Network Security
A cold site in disaster recovery is an empty backup location that needs to be equipped after a disaster. A warm site is partially equipped and can be quickly made operational. A hot site is a fully operational backup site that can immediately take over network operations. In active-active high availability, both systems are fully operational and share the load, while in active-passive, one system is a backup and idle until needed. Tabletop exercises simulate disaster scenarios and test response processes. Validation tests verify that disaster recovery procedures are effective. DHCP reservations assign specific IP addresses to devices based on their MAC addresses. A DHCP scope is a range of IP addresses that the DHCP server is configured to assign. The lease time in DHCP is the duration for which an IP address is assigned to a client before it must be renewed. The DHCP option field allows a network administrator to provide additional configuration information to DHCP clients. A DHCP relay forwards DHCP requests from clients to a DHCP server on a different subnet. DHCP exclusions prevent specific IP addresses within the DHCP scope from being assigned to clients.
IPv6 and Network Security
Stateless Address Autoconfiguration (SLAAC) enables IPv6 devices to automatically configure an IPv6 address based on the network prefix and device's MAC address without needing a DHCP server. DNS translates human-readable domain names into IP addresses. DNSSEC adds security to DNS by verifying the authenticity of responses to prevent attacks like DNS spoofing. DNS over HTTPS (DoH) encrypts DNS queries to ensure privacy. DNS over TLS (DoT) encrypts DNS queries to protect user privacy. An A record in DNS maps a domain name to its corresponding IPv4 address, while a quad-A record maps a domain name to its corresponding IPv6 address. A CNAME record in DNS maps an alias or subdomain to the main domain's A record. A mail exchange (MX) record specifies the mail server responsible for receiving email for the domain. A text (TXT) record stores text-based information such as SPF records or verification keys. A name server (NS) record defines the authoritative DNS servers for a domain. A pointer (PTR) record maps an IP address to a domain name for reverse DNS lookups. A forward zone in DNS maps domain names to IP addresses for normal DNS lookups, while a reverse zone maps IP addresses to domain names for reverse DNS lookups.
Network Security and Troubleshooting
Authoritative DNS servers hold the original records, while non-authoritative servers cache records from other sources. Primary DNS servers hold the original zone records, while secondary DNS servers provide backup and load balancing. A recursive DNS query is where the DNS server takes responsibility for resolving the domain name by querying other servers. The hosts file is a local file used to map hostnames to IP addresses manually, bypassing DNS queries. Network Time Protocol (NTP) synchronizes the clocks of computers and network devices. Precision Time Protocol (PTP) synchronizes clocks across a network with higher precision than NTP. Network Time Security (NTS) provides security enhancements for NTP by preventing man-in-the-middle attacks. A site-to-site VPN connects two or more networks securely over the internet. A client-to-site VPN allows individual users to securely connect to a remote network over the internet. A clientless VPN does not require any client software to be installed on the user's device. A split tunnel allows some traffic to go through the VPN and other traffic to go directly to the internet, while a full tunnel routes all traffic through the VPN. Secure Shell (SSH) provides a secure method for remote access to devices and encrypted communication over an insecure network.
Network Management and Security Protocols
A graphical user interface (GUI) provides a visual interface that simplifies management tasks. An Application Programming Interface (API) allows software applications to communicate and interact with each other. A console connection provides a direct physical connection to a network device for configuration and troubleshooting. A jump box or host acts as a secure intermediary that provides remote access to other devices in a network. Out-of-band management uses a separate dedicated network for management traffic. Encryption for data in transit secures data while it is being transmitted over the network. Encryption for data at rest protects stored data from unauthorized access. A certificate in a Public Key Infrastructure (PKI) system verifies the identity of entities and encrypts communication. A self-signed certificate is signed by the same entity that created it and is used primarily for internal applications. Identity and Access Management (IAM) ensures that only authorized users can access specific resources. Authentication verifies the identity of a user or device before granting access. Multi-Factor Authentication (MFA) requires users to present multiple forms of verification. Single Sign-On (SSO) allows users to log in once and gain access to multiple applications. Remote Authentication Dial-In User Service (RADIUS) provides centralized authentication, authorization, and accounting for users accessing a network remotely.
Network Security and Physical Security Measures
Lightweight Directory Access Protocol (LDAP) is used to access and manage directory services for user authentication and authorization. Security Assertion Markup Language (SAML) allows for secure exchange of authentication and authorization data between parties, typically used in web-based single sign-on. Terminal Access Controller Access-Control System Plus (TACACS+) is a protocol for managing device access and providing authentication, authorization, and accounting for network devices. Time-based authentication requires users to provide credentials that are only valid for a specific time period. The principle of least privilege ensures that users only have the minimal level of access necessary to perform their job functions. Role-Based Access Control (RBAC) is a system where access to resources is based on the user's assigned role within an organization. Geo-fencing creates a virtual boundary around a geographical area and triggers actions when a device enters or exits it. Cameras monitor and record activity within a specific area for surveillance and evidence gathering. Locks restrict physical access to authorized personnel and prevent unauthorized access to sensitive areas.
Cybersecurity Threats and Mitigation Techniques
A honeypot is a decoy system designed to attract and detect attackers by simulating vulnerable resources. A honey net is a network of honeypots designed to mimic a real network and attract a broader range of attacks. Risk in cybersecurity is the potential for harm or loss caused by vulnerabilities that can be exploited by threats. A vulnerability is a weakness in a system or network that can be exploited by a threat actor. An exploit is a method used to take advantage of a vulnerability to gain unauthorized access or cause harm. A threat is any potential danger or harmful event that can exploit a vulnerability to cause damage. The CIA triad stands for Confidentiality, Integrity, and Availability, the core principles for securing information systems. Data locality is the requirement to store data in a specific geographic location to comply with legal or regulatory standards. The Payment Card Industry Data Security Standard (PCI DSS) focuses on protecting credit card data and maintaining secure payment systems. The General Data Protection Regulation (GDPR) protects the personal data of individuals within the European Union.
Network Security and Troubleshooting Techniques
Network segmentation is enforced by dividing the network into smaller segments or zones to limit access between different parts of the network. A significant concern when connecting Internet of Things (IoT) devices to a network is the lack of security controls and potential vulnerabilities in IoT devices. Supervisory Control and Data Acquisition (SCADA) systems primarily manage critical infrastructure systems. Industrial Control Systems (ICS) monitor and control industrial processes. Operational Technology (OT) refers to systems that monitor and control physical processes, while Information Technology (IT) focuses on information management and data systems. A key consideration when implementing a guest network is to provide internet access to guests while isolating them from the internal network. Bring Your Own Device (BYOD) refers to allowing employees to use their personal devices to access the corporate network.
Network Attacks and Security Measures
The primary purpose of a Denial of Service (DoS) attack is to overwhelm a system or network with excessive traffic, making it unavailable. A Distributed Denial of Service (DDoS) attack uses multiple compromised systems to flood the target with traffic. VLAN hopping is an attack where an attacker sends packets to a VLAN on one network and gains unauthorized access to another VLAN. The primary goal of a MAC flooding attack is to flood a network switch with a large number of MAC addresses, causing it to become unable to forward traffic properly. ARP poisoning is an attack where an attacker sends falsified ARP messages to associate their MAC address with the IP address of another device. ARP spoofing is an attack where an attacker impersonates a legitimate device on the network by sending false ARP messages. DNS poisoning is an attack that manipulates DNS records to redirect users to malicious websites.
Network Security Threats and Social Engineering
Rogue DHCP servers can assign incorrect IP addresses, causing network disruptions or unauthorized access. A rogue access point (AP) can allow unauthorized users to connect to the network, potentially exposing sensitive data. An evil twin attack involves an attacker setting up a rogue wireless access point with the same name as a legitimate access point to intercept user traffic. An on-path attack is where an attacker intercepts or alters communication between two devices without being detected. Phishing is an attack where an attacker impersonates a legitimate entity to trick users into revealing sensitive information. Dumpster diving is the practice of searching through discarded materials to find sensitive information. Shoulder surfing is an attack where an attacker watches over someone's shoulder to obtain sensitive information. Tailgating is an attack where an unauthorized person gains physical access to a restricted area by following an authorized person. Malware is software designed to harm, exploit, or otherwise compromise a computer or network system.
Device Hardening and Network Access Control
Disabling unused ports and services in device hardening reduces the attack surface and minimizes potential security vulnerabilities. Changing default passwords prevents unauthorized access from attackers who might know or guess default credentials. Network Access Control (NAC) enforces policies that determine what devices can access the network based on security posture. Port security prevents unauthorized devices from connecting to the network through unused ports. 802.1X provides port-based network access control, requiring authentication before granting access to the network. MAC filtering allows or blocks network access based on the device's MAC address. Key management involves the creation, distribution, storage, and destruction of cryptographic keys to ensure secure communications. Access Control Lists (ACLs) define rules that specify which users or devices can access network resources based on IP address, port, or protocol. URL filtering blocks or restricts access to specific websites based on their URL. Content filtering restricts access to content based on its type, such as blocking adult content or malware-laden websites.
Network Security Zones and Disaster Recovery
A trusted zone contains resources and devices that are secure and protected, while an untrusted zone contains external or less secure resources. A screened subnet is placed between a trusted internal network and an untrusted external network, often used for DMZs. The first step when troubleshooting a network issue is to gather information to understand the nature of the problem. Questioning users helps gather insights about the issue from their perspective. Identifying symptoms involves
