CompTIA Updated 220-1102 Exam Questions and Answers by lilianna

The error "This site cannot be reached" often indicates a problem with DNS (Domain Name System) resolution, where the browser is unable to translate a website's domain name into its corresponding IP address. Since the laptop was set to use DHCP (Dynamic Host Configuration Protocol) at home, it's possible that it's not receiving the correct DNS server information from the home network, or the DNS servers it was using at work are not accessible from the home network.

DNS: Checking and possibly correcting the DNS settings to ensure they are appropriate for the home network might resolve the browsing issue. The user can try using public DNS servers like those provided by Google (8.8.8.8 and 8.8.4.4) or Cloudflare (1.1.1.1) if the default DNS servers provided by the home ISP are not working properly.

HTTPS (A) is a protocol for secure communication over a computer network but is not something that needs to be configured on the user's end to solve this type of issue. VLAN (B) stands for Virtual Local Area Network and is more related to network segmentation and management within larger networks, not typically applicable to home internet issues. SMTP (D) stands for Simple Mail Transfer Protocol, which is used for sending emails, not for general web browsing issues.

The IT manager's caution regarding the new applications not having a detrimental effect on company finances points directly to concerns about the business impact. This encompasses potential costs associated with upgrading legacy systems, compatibility issues that might arise from running new applications on old infrastructure, and the risks of system downtime or reduced performance affecting business operations. The focus here is on ensuring that the integration of new applications into the legacy system does not incur unexpected expenses or disrupt critical business processes.

A boot sector virus infects the master boot record (MBR) of a hard drive, the sector that contains information required to start the operating system after the computer is turned on. This type of virus is particularly insidious because it loads into memory immediately upon booting and before most antivirus programs start. This makes it possible for the virus to evade detection and removal, and can easily reinfect a system even after the operating system is reinstalled if the boot sector is not cleaned.

Boot sector virus: Given that the malware infection returned after the OS reinstallation, it's likely that the virus was not removed from the boot sector during the reinstallation process. Reinstalling the OS without cleaning the boot sector won't remove the infection, allowing the virus to continue to affect the system.

Other options:

Trojan: A Trojan is a type of malware that disguises itself as legitimate software. While Trojans can be persistent, the reinstallation of the OS should remove any Trojans unless they are reintroduced after installation.

Spyware: Spyware is designed to gather information about a person or organization without their knowledge. Like Trojans, spyware should be removed with an OS reinstallation unless it is reintroduced in some way.

Rootkit: Rootkits are designed to enable continued privileged access to a computer while actively hiding their presence. While a rootkit could potentially survive an OS reinstall if it infects the firmware or certain areas outside the OS, the scenario described points more specifically to a boot sector virus, especially considering the immediate return of the infection after OS reinstallation.

DNS (Domain Name System) lookups are essential for translating human-friendly domain names into IP addresses that computers use to communicate. DNS typically uses port 53 for its communication.

In the provided firewall output, various ports are either allowed or blocked for outgoing traffic. For DNS recursion, which is the process of resolving domain names to IP addresses, port 53 must be open.

Port 53: This is the standard port used by DNS for queries and responses. The fact that it is currently blocked (as per the firewall output) is the reason why DNS lookups are failing. Opening port 53 will allow the DNS requests to pass through the firewall, enabling the resolution of domain names to IP addresses.

Other ports mentioned in the output are used for different services and protocols:

Port 1 is generally not used for standard services.

Port 445 is associated with SMB (Server Message Block) for file sharing in Windows environments.

Port 123 is used by NTP (Network Time Protocol) for time synchronization.

Port 80 is used for HTTP traffic, which is web traffic but not related to DNS lookups.