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Difficulty: HardIP Addressing and Network Configuration

A network technician is configuring a static network setup on a point-of-sale (POS) terminal. The terminal must communicate with local cash registers on the 192.168.4.0/24192.168.4.0/24 network and access a cloud-based payment service using domain name resolution.

The technician applies the following network configuration:
- IP Address: 192.168.4.75192.168.4.75
- Subnet Mask: 255.255.255.0255.255.255.0
- Default Gateway: 192.168.5.1192.168.5.1
- DNS Server: 169.254.1.1169.254.1.1

Testing reveals that the terminal can successfully ping local devices (such as 192.168.4.10192.168.4.10), but it cannot connect to external networks or resolve the payment service domain name.

Which TWO configuration issues are responsible for the external connectivity and name resolution failures? (Select TWO.)

  1. The default gateway is configured on a different IP subnet than the host terminalAnswer
  2. The DNS server address is assigned an Automatic Private IP Addressing (APIPA) addressAnswer
  3. C
    An unmanaged Layer 2 switch is missing between the terminal and gateway to interconnect subnets
  4. D
    The DNS server cannot resolve hostnames because it lacks an active DHCP server scope lease

Answer

The connectivity and resolution failures are caused by configuring a default gateway on a different subnet than the host (192.168.5.1192.168.5.1 vs 192.168.4.0/24192.168.4.0/24) and assigning a non-routable APIPA address (169.254.1.1169.254.1.1) as the DNS server.
A host's default gateway must share the exact same subnet IP range as the host interface (192.168.4.0/24192.168.4.0/24) to be reachable. Furthermore, 169.254.1.1169.254.1.1 is an APIPA address (169.254.0.0/16169.254.0.0/16), which is non-routable and invalid for external DNS server resolution.

Step-by-Step Solution

1
Analyze host IP address and subnet mask to determine the local network boundary.
An IP of 192.168.4.75192.168.4.75 with mask 255.255.255.0255.255.255.0 defines a local subnet range of 192.168.4.1192.168.4.1 through 192.168.4.254192.168.4.254.
To route off-network traffic, the default gateway must reside within this local host address range.
2
Examine the default gateway IP address.
The gateway address 192.168.5.1192.168.5.1 belongs to the 192.168.5.0/24192.168.5.0/24 network, making it unreachable directly via local ARP resolution.
A host cannot forward packets to a gateway that does not exist on its local physical link.
3
Examine the DNS server configuration.
The configured DNS server 169.254.1.1169.254.1.1 is an APIPA address (169.254.0.0/16169.254.0.0/16).
APIPA addresses are link-local addresses automatically generated when DHCP fails and cannot be routed across network boundaries to provide external domain resolution.

Key Concept

Default gateway subnet matching and APIPA address scope limitations
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Topics

IP Addressing and Network Configuration

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