- (Topic 3)
A network technician is troubleshooting a connectivity issue. All users within the network report that they are unable to navigate to websites on the internet; however, they can still access local network resources. The technician issues a command and receives the following results:
Which of the following best explains the result of this command?
Correct Answer:
D
The users are unable to navigate to websites on the internet but can access local network resources, indicating a possible DNS issue. The ping command result showing “TTL expired in transit” suggests that packets are not reaching their destination due to a DNS misconfiguration that is not resolving website names into IP addresses correctly3. A possible solution is to check and correct the DNS server settings on the network devices4.
References: 3: What does “TTL expired in transit” mean?54: CompTIA Network+ N10-008 Cert Guide - Chapter 14: Network Monitoring2
- (Topic 3)
A technician is setting up DNS records on local servers for the company's cloud DNS to enable access by hostname. Which of the following records should be used?
Correct Answer:
A
An A record, also known as an address record, is a type of DNS record that maps a hostname to an IPv4 address. An A record is used to resolve a domain name to an IP address, so that clients can connect to the server or service by using the domain name instead of the IP address. For example, an A record can map www.example.com to 192.0.2.1.
An A record is the most common type of DNS record for cloud DNS, as it allows the company to use a custom domain name for their cloud services, such as web hosting, email, or storage. An A record can also be used to create subdomains, such as blog.example.com or mail.example.com, that point to different IP addresses or servers. The other options are not correct because they are not the best type of DNS record for cloud DNS. They are:
✑ MX. MX stands for mail exchange, and it is a type of DNS record that specifies the
mail servers that are responsible for receiving and delivering email messages for a domain name. MX records are used for email services, but they are not sufficient for cloud DNS, as they do not map a hostname to an IP address.
✑ CNAME. CNAME stands for canonical name, and it is a type of DNS record that specifies an alias name for another domain name. CNAME records are used to create multiple names for the same IP address or server, such as www.example.com and example.com. CNAME records are useful for cloud DNS, but they are not the best type, as they depend on another A record to resolve the IP address.
✑ NS. NS stands for name server, and it is a type of DNS record that delegates a DNS zone to an authoritative server. NS records are used to specify which DNS servers are responsible for answering queries for a domain name or a subdomain. NS records are essential for cloud DNS, but they are not the best type, as they do not map a hostname to an IP address.
References1: DNS records overview | Google Cloud2: Network+ (Plus) Certification | CompTIA IT Certifications3: ClouDNS: What is a DNS record?
- (Topic 3)
A network engineer is monitoring a fiber uplink to a remote office and notes the uplink has been operating at 100
Correct Answer:
A
When a fiber uplink is operating at 100
- (Topic 3)
Which of the following records can be used to track the number of changes on a DNS zone?
Correct Answer:
A
The DNS ‘start of authority’ (SOA) record stores important information about a domain or zone such as the email address of the administrator, when the domain was last updated, and how long the server should wait between refreshes. All DNS zones need an SOA record in order to conform to IETF standards. SOA records are also important for zone transfers.
- (Topic 3)
A technician is investigating why a PC cannot reach a file server with the IP address 192.168.8.129. Given the following TCP/IP network configuration:
Which of the following configurations on the PC is incorrect?
Correct Answer:
C
The default gateway is the IP address of the router that connects the PC to other networks. The default gateway should be on the same subnet as the PC’s IPv4 address. However, in this case, the default gateway is 192.168.9.1, which is on a different subnet than the PC’s IPv4 address of 192.168.8.15. Therefore, the default gateway configuration on the PC is incorrect and prevents the PC from reaching the file server on another subnet.
