A workstation on a newly segmented corporate network is experiencing connectivity issues. … — CompTIA A+ (Core 1 & Core 2)

A workstation on a newly segmented corporate network is experiencing connectivity issues. A technician inspects the host configuration and obtains the following IP configuration details from command output:

- IPv4 Address: $10.10.20.80$
- Subnet Mask: $255.255.255.224$
- Default Gateway: $10.10.20.97$
- Primary DNS Server: $10.10.20.66$

Network documentation indicates that $10.10.20.66$ functions strictly as the local DHCP server leasing IP addresses, while the actual internal DNS server is located at $10.10.20.2$ . Which TWO of the following misconfigurations directly explain why this workstation cannot reach devices on external subnets or resolve hostnames by domain name?

The default gateway IP address resides outside the subnet boundaries of the host's assigned IPv4 address.Cevap
B
The host was automatically assigned an APIPA address because the local gateway did not respond to ARP requests.
The DNS server entry is misconfigured with the IP address of a DHCP server rather than a domain name resolution server.Cevap
D
An unmanaged Layer 2 switch must be deployed between the host and the gateway to bridge communications between different IP subnets.

Cevap

The workstation is unable to reach external subnets because its default gateway IP address is on a different subnet boundary than its own IP address, and domain name resolution fails because the DNS server address points to a DHCP server instead of a DNS server.

The correct options identify that the default gateway is placed on a separate

/27

subnet block (

10.10.20.96/27

) outside the host's local range (

10.10.20.64/27

), rendering off-subnet routing impossible, and that assigning the DHCP server IP address to the DNS field causes hostname resolution requests to fail because port 53 DNS services are not running on the DHCP server.

Adım Adım Çözüm

Calculate the IP subnet boundaries for the host.

A subnet mask of

255.255.255.224

corresponds to a prefix length of

/27

with block sizes of

32

(

256 - 224 = 32

). For the host IP

10.10.20.80

, the subnet block starts at

10.10.20.64

and ends at

10.10.20.95

. Valid host addresses in this subnet range from

10.10.20.65

10.10.20.94

Determining the subnet boundary is required to check if the host and default gateway share the same local network segment.

Evaluate the configured default gateway against the host's subnet.

The configured default gateway is

10.10.20.97

, which falls into the next subnet block (

10.10.20.96/27

). Because the gateway is not in the same IP subnet as the host, local Layer 2 ARP communication cannot reach the gateway interface directly.

A host must have a default gateway configured on its own local IP subnet to route packets outside the local network.

Evaluate the DNS server assignment against service roles.

The Primary DNS Server address is set to

10.10.20.66

, which documentation identifies as a DHCP server. DHCP servers lease network parameters and do not listen on UDP/TCP port 53 to resolve domain names to IP addresses.

Hostnames cannot be resolved unless the DNS client points to an operational DNS resolver.

Anahtar Kavram

Subnet Masking and Network Service Role Allocation

Soru

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Konular

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