Network+/Objectives

1.0 Networking Concepts

1.1 Explain concepts related to the Open Systems Interconnection (OSI) reference model.

1.2 Compare and contrast networking appliances, applications, and functions.

Physical and virtual appliances
- Router
- Switch
- Firewall
- Intrusion detection system (IDS)/intrusion prevention system (IPS)
- Load balancer
- Proxy
- Network-attached storage (NAS)
- Storage area network (SAN)
- Wireless
  - Access point (AP)
  - Controller

Applications
- Content delivery network (CDN)
Functions
- Virtual private network (VPN)
- Quality of service (QoS)
- Time to live (TTL)

1.3 Summarize cloud concepts and connectivity options.

Network functions virtualization (NFV)
Virtual private cloud (VPC)
Network security groups
Network security lists
Cloud gateways
- Internet gateway
- Network address translation (NAT) gateway
Cloud connectivity options
- VPN
- Direct Connect

Deployment models
- Public
- Private
- Hybrid
Service models
- Software as a service (SaaS)
- Infrastructure as a service (IaaS)
- Platform as a service (PaaS)
Scalability
Elasticity
Multitenancy

1.4 Explain common networking ports, protocols, services, and traffic types.

See Quizlet.
Protocols	Ports
File Transfer Protocol (FTP)	20/21
Secure File Transfer Protocol (SFTP)	22
Secure Shell (SSH)	22
Telnet	23
Simple Mail Transfer Protocol (SMTP)	25
Domain Name System (DNS)	53
Dynamic Host Configuration Protocol (DHCP)	67/68
Trivial File Transfer Protocol (TFTP)	69
Hypertext Transfer Protocol (HTTP)	80
Network Time Protocol (NTP)	123
Simple Network Management Protocol (SNMP)	161/162
Lightweight Directory Access Protocol (LDAP)	389
Hypertext Transfer Protocol Secure (HTTPS)	443
Server Message Block (SMB)	445
Syslog	514
Simple Mail Transfer Protocol Secure (SMTPS)	587
Lightweight Directory Access Protocol over SSL (LDAPS)	636
Structured Query Language (SQL) Server	1433
Remote Desktop Protocol (RDP)	3389
Session Initiation Protocol (SIP)	5060/5061

Internet Protocol (IP) types
- Internet Control Message Protocol (ICMP)
- Transmission Control Protocol (TCP)
- User Datagram Protocol (UDP)
- Generic Routing Encapsulation (GRE)
- Internet Protocol Security (IPSec)
  - Authentication Header (AH)
  - Encapsulating Security Payload (ESP)
  - Internet Key Exchange (IKE)
Traffic types
- Unicast
- Multicast
- Anycast
- Broadcast

1.5 Compare and contrast transmission media and transceivers.

Wireless
- 802.11 standards
- Cellular
- Satellite
Wired
- 802.3 standards
- Single-mode vs. multimode fiber
- Direct attach copper (DAC) cable
  - Twinaxial cable
- Coaxial cable
- Cable speeds
- Plenum vs. non-plenum cable

Transceivers
- Protocol
  - Ethernet
  - Fibre Channel (FC)
- Form factors
  - Small form-factor pluggable (SFP)
  - Quad small form-factor pluggable (QSFP)
Connector types
- Subscriber connector (SC)
- Local connector (LC)
- Straight tip (ST)
- Multi-fiber push on (MPO)
- Registered jack (RJ)11
- RJ45
- F-type
- Bayonet Neill–Concelman (BNC)

1.6 Compare and contrast network topologies, architectures, and types.

Three-tier hierarchical model
- Core
- Distribution
- Access
Collapsed core
Traffic flows
- North-south
- East-west

1.7 Given a scenario, use appropriate IPv4 network addressing.

Public vs. private
- Automatic Private IP Addressing (APIPA)
- RFC1918
- Loopback/localhost
Subnetting
- Variable Length Subnet Mask (VLSM)
- Classless Inter-domain Routing (CIDR)

IPv4 address classes
- Class A
- Class B
- Class C
- Class D
- Class E

1.8 Summarize evolving use cases for modern network environments

Software-defined network (SDN) and software-defined wide area network (SD-WAN)
- Application aware
- Zero-touch provisioning
- Transport agnostic
- Central policy management
Virtual Extensible Local Area Network (VXLAN)
- Data center interconnect (DCI)
- Layer 2 encapsulation
Zero trust architecture (ZTA)
- Policy-based authentication
- Authorization
- Least privilege access
Secure Access Secure Edge (SASE)/Security Service Edge (SSE)

Infrastructure as code (IaC)
- Automation
  - Playbooks/templates/reusable tasks
  - Configuration drift/compliance
  - Upgrades
  - Dynamic inventories
- Source control
  - Version control
  - Central repository
  - Conflict identification
  - Branching
IPv6 addressing
- Mitigating address exhaustion
- Compatibility requirements
  - Tunneling
  - Dual stack
  - NAT64

2.0 Network Implementation

2.1 Explain characteristics of routing technologies.

Static routing
Dynamic routing
- Border Gateway Protocol (BGP)
- Enhanced Interior Gateway Routing Protocol (EIGRP)
- Open Shortest Path First (OSPF)
Route selection
- Administrative distance
- Prefix length
- Metric

Address translation
- NAT
- Port address translation (PAT)
First Hop Redundancy Protocol (FHRP)
Virtual IP (VIP)
Subinterfaces

2.2 Given a scenario, configure switching technologies and features.

Virtual Local Area Network (VLAN)
- VLAN database
- Switch Virtual Interface (SVI)
Spanning tree
Maximum transmission unit (MTU)
- Jumbo frames

Interface configuration
- Native VLAN
- Voice VLAN
- 802.1Q tagging
- Link aggregation
- Speed
- Duplex

2.3 Given a scenario, select and configure wireless devices and technologies.

Channels
- Channel width
- Non-overlapping channels
- Regulatory impacts
  - 802.11h
Frequency options
- 2.4GHz
- 5GHz
- 6GHz
- Band steering

Service set identifier (SSID)
- Basic service set identifier (BSSID)
- Extended service set identifier (ESSID)

Network types
- Mesh networks
- Ad hoc
- Point to point
- Infrastructure
Encryption
- Wi-Fi Protected Access 2 (WPA2)
- WPA3
Guest networks
- Captive portals
Authentication
- Pre-shared key (PSK) vs. Enterprise
Antennas
- Omnidirectional vs. directional
Autonomous vs. lightweight access point

2.4 Explain important factors of physical installations.

Important installation implications
- Locations
  - Intermediate distribution frame (IDF)
  - Main distribution frame (MDF)
- Rack size
- Port-side exhaust/intake
- Cabling
  - Patch panel
  - Fiber distribution panel
- Lockable

Power
- Uninterruptible power supply (UPS)
- Power distribution unit (PDU)
- Power load
- Voltage
Environmental factors
- Humidity
- Fire suppression
- Temperature

3.0 Network Operations

3.1 Explain the purpose of organizational processes and procedures.

Documentation
- Physical vs. logical diagrams
- Rack diagrams
- Cable maps and diagrams
- Network diagrams
  - Layer 1
  - Layer 2
  - Layer 3
- Asset inventory
  - Hardware
  - Software
  - Licensing
  - Warranty support
- IP address management (IPAM)
- Service-level agreement (SLA)
- Wireless survey/heat map

Life-cycle management
- End-of-life (EOL)
- End-of-support (EOS)
- Software management
  - Patches and bug fixes
  - Operating system (OS)
  - Firmware
- Decommissioning
Change management
- Request process tracking/service request
Configuration management
- Production configuration
- Backup configuration
- Baseline/golden configuration

3.2 Given a scenario, use network monitoring technologies.

Methods
- SNMP
  - Traps
  - Management information base (MIB)
  - Versions
  - v2c
  - v3
  - Community strings
  - Authentication
- Flow data
- Packet capture
- Baseline metrics
  - Anomaly alerting/notification
- Log aggregation
  - Syslog collector
  - Security information and event management (SIEM)
- Application programming interface (API) integration
- Port mirroring

Solutions
- Network discovery
  - Ad hoc
  - Scheduled
- Traffic analysis
- Performance monitoring
- Availability monitoring
- Configuration monitoring

3.3 Explain disaster recovery (DR) concepts.

DR metrics
- Recovery point objective (RPO)
- Recovery time objective (RTO)
- Mean time to repair (MTTR)
- Mean time between failures (MTBF)
DR sites

High-availability approaches
- Active-active
- Active-passive
Testing
- Tabletop exercises
- Validation tests

3.4 Given a scenario, implement IPv4 and IPv6 network services.

Dynamic addressing
- DHCP
  - Reservations
  - Scope
  - Lease time
  - Options
  - Relay/IP helper
  - Exclusions
- Stateless address autoconfiguration (SLAAC)
Time protocols
- NTP
- Precision Time Protocol (PTP)
- Network Time Security (NTS)

Name resolution
- DNS
  - DNS Security Extensions (DNSSEC)
  - DNS over HTTPS (DoH) and DNS over TLS (DoT)
  - Record types
  - Address (A)
  - AAAA
  - Canonical name (CNAME)
  - Mail exchange (MX)
  - Text (TXT)
  - Nameserver (NS)
  - Pointer (PTR)
  - Zone types
  - Forward
  - Reverse
  - Authoritative vs. non-authoritative
  - Primary vs. secondary
  - Recursive
- Hosts file

3.5 Compare and contrast network access and management methods.

Site-to-site VPN
Client-to-site VPN
- Clientless
- Split tunnel vs. full tunnel
Connection methods
- SSH
- Graphical user interface (GUI)
- API
- Console
Jump box/host
In-band vs. out-of-band management

4.0 Network Security

4.1 Explain the importance of basic network security concepts.

Logical security
- Encryption
  - Data in transit
  - Data at rest
- Certificates
  - Public key infrastructure (PKI)
  - Self-signed
- Identity and access management (IAM)
  - Authentication
  - Multifactor authentication (MFA)
  - Single sign-on (SSO)
  - Remote Authentication Dial-in User Service (RADIUS)
  - LDAP
  - Security Assertion Markup Language (SAML)
  - Terminal Access Controller Access Control System Plus (TACACS+)
  - Time-based authentication
  - Authorization
  - Least privilege
  - Role-based access control
- Geofencing

Physical security
- Camera
- Locks
Deception technologies
- Honeypot
- Honeynet
Common security terminology
Audits and regulatory compliance
- Data locality
- Payment Card Industry Data Security Standards (PCI DSS)
- General Data Protection Regulation (GDPR)
Network segmentation enforcement
- Internet of Things (IoT) and Industrial Internet of Things (IIoT)
- Supervisory control and data acquisition (SCADA), industrial control system (ICS), operational technology (OT)
- Guest
- Bring your own device (BYOD)

4.2 Summarize various types of attacks and their impact to the network.

Denial-of-service (DoS)/distributed denial-of-service (DDoS)
VLAN hopping
Media Access Control (MAC) flooding
Address Resolution Protocol (ARP) poisoning
ARP spoofing
DNS poisoning
DNS spoofing

4.3 Given a scenario, apply network security features, defense techniques, and solutions.

Device hardening
- Disable unused ports and services
- Change default passwords
Network access control (NAC)

Key management
Security rules
- Access control list (ACL)
- Uniform Resource Locator (URL) filtering
- Content filtering
Zones
- Trusted vs. untrusted
- Screened subnet

5.0 Network Troubleshooting

5.1 Explain the troubleshooting methodology.

1. Identify the problem

Gather information
Question users
Identify symptoms
Determine if anything has changed
Duplicate the problem, if possible
Approach multiple problems individually

2. Establish a theory of probable cause

Question the obvious
Consider multiple approaches
- Top-to-bottom/bottom-to-top OSI model
- Divide and conquer

3. Test the theory to determine the cause

If theory is confirmed, determine next steps to resolve problem
If theory is not confirmed, establish a new theory or escalate

4. Establish a plan of action to resolve the problem and identify potential effects

5. Implement the solution or escalate as necessary

6. Verify full system functionality and implement preventive measures if applicable

7. Document findings, actions, outcomes, and lessons learned throughout the process

5.2 Given a scenario, troubleshoot common cabling and physical interface issues.

Cable issues
- Incorrect cable
  - Single mode vs. multimode
  - Category 5/6/7/8
  - Shielded twisted pair (STP) vs. unshielded twisted pair (UTP)
- Signal degradation
  - Crosstalk
  - Interference
  - Attenuation
- Improper termination
- Transmitter (TX)/Receiver (RX) transposed

Interface issues
- Increasing interface counters
  - Cyclic redundancy check (CRC)
  - Runts
  - Giants
  - Drops
- Port status
  - Error disabled
  - Administratively down
  - Suspended
Hardware issues
- Power over Ethernet (PoE)
  - Power budget exceeded
  - Incorrect standard
- Transceivers
  - Mismatch
  - Signal strength

5.3 Given a scenario, troubleshoot common issues with network services.

Switching issues
- STP
  - Network loops
  - Root bridge selection
  - Port roles
  - Port states
- Incorrect VLAN assignment
- ACLs

Route selection
- Routing table
- Default routes
Address pool exhaustion
Incorrect default gateway
Incorrect IP address
- Duplicate IP address
Incorrect subnet mask

5.4 Given a scenario, troubleshoot common performance issues.

Wireless
- Interference
  - Channel overlap
- Signal degradation or loss
- Insufficient wireless coverage
- Client disassociation issues
- Roaming misconfiguration

5.5 Given a scenario, use the appropriate tool or protocol to solve networking issues.

Software tools
- Protocol analyzer
- Command line
  - ping
  - traceroute/tracert
  - nslookup
  - tcpdump
  - dig
  - netstat
  - ip/ifconfig/ipconfig
  - arp
- Nmap
- Link Layer Discovery Protocol (LLDP)/Cisco Discovery Protocol (CDP)
- Speed tester

Hardware tools
- Toner
- Cable tester
- Taps
- Wi-Fi analyzer
- Visual fault locator
Basic networking device commands
- show mac-address-table
- show route
- show interface
- show config
- show arp
- show vlan
- show power