For a web server that requires all connections to be encrypted, port 80 (HTTP) should be disabled. Port 80 is used for unencrypted web traffic, whereas port 443 is used for HTTPS, which provides encrypted communication.
Port 80 (HTTP): This port is used for unsecured web traffic. Disabling this port ensures that all web traffic must use HTTPS, which encrypts the data in transit.
Port 443 (HTTPS): This port is used for secure web traffic via SSL/TLS encryption. Keeping this port open ensures that secure connections can be made to the web server.
Other Ports:
Port 22: Used for SSH, providing secure remote access and file transfers.
Port 587: Used for secure email submission (SMTP) with encryption.
Network Reference:
CompTIA Network+ N10-007 Official Certification Guide: Discusses the roles and security implications of various ports and protocols.
Cisco Networking Academy: Provides training on secure web server configuration and port management.
Network+ Certification All-in-One Exam Guide: Covers port security and best practices for securing web servers.

Definition of RPO:
Recovery Point Objective (RPO) is a disaster recovery metric that describes the maximum acceptable amount of data loss measured in time. It indicates the point in time to which data must be recovered to resume normal operations after a disaster.
For example, if the RPO is set to 24 hours, then the business could tolerate losing up to 24 hours' worth of data in the event of a disruption.
Why RPO is Important:
RPO is critical for determining backup frequency and helps businesses decide how often they need to back up their data. A lower RPO means more frequent backups and less potential data loss.
Comparison with Other Metrics:
MTTR (Mean Time to Repair): Refers to the average time required to repair a system or component and return it to normal operation.
RTO (Recovery Time Objective): The maximum acceptable length of time that a computer, system, network, or application can be down after a failure or disaster occurs.
MTBF (Mean Time Between Failures): The predicted elapsed time between inherent failures of a system during operation.
How RPO is Used in Disaster Recovery:
Organizations establish RPOs to ensure that they can recover data within a timeframe that is acceptable to business operations. This involves creating a backup plan that meets the RPO requirements.
Reference:
CompTIA Network+ study materials and certification guides.

NAT (Network Address Translation) helps hide internal IP addresses from external networks, adding a layer of security by preventing direct access to internal systems from the outside.

Comprehensive and Detailed Step-by-Step
nslookup allows querying DNS records to verify if the new server is correctly resolving domain names.
ping (A) tests basic connectivity, not DNS configuration.
tracert (B) shows network path latency but doesn't test DNS.
tcpdump (C) captures packets but isn't ideal for DNS verification.
Reference: CompTIA Network+ N10-009 Official Documentation - DNS Testing Tools.

When a network administrator installs a new Network Interface Card (NIC) and users are unable to reach the server, one of the common issues is the use of an incorrect cable type. Network cables must match the specifications required by the NIC and the network infrastructure (e.g., Cat5e, Cat6 for Ethernet).
NIC Compatibility: The new NIC might require a specific type of cable to function properly. Using a cable not rated for the NIC's required speeds or capabilities can result in connectivity issues.
Cable Standards: Different NICs and network devices might need different cabling standards (straight-through vs. crossover cables, or specific fiber optic types).
Connection Types: Ensuring that the cable connectors are appropriate for the NIC ports (e.g., RJ45 for Ethernet, LC connectors for fiber optics).
Network Reference:
CompTIA Network+ N10-007 Official Certification Guide: Discusses network cabling standards and NIC specifications.
Cisco Networking Academy: Provides insights into cabling and NIC configurations for optimal network performance.
Network+ Certification All-in-One Exam Guide: Offers comprehensive details on troubleshooting network connectivity issues, including cabling problems.