Question

Difficulty: HardIP Addressing and Network Configuration

A network technician is troubleshooting a connectivity issue on a newly configured workstation located on the local subnet 172.16.45.0/24172.16.45.0/24. The workstation can successfully ping other local devices on the same switch, but it cannot access any servers on adjacent subnets or browse external internet sites. The technician executes `ipconfig /all` on the workstation and receives the following output:

- IPv4 Address: 172.16.45.110172.16.45.110
- Subnet Mask: 255.255.255.0255.255.255.0
- Default Gateway: 172.16.44.1172.16.44.1
- DNS Server: 172.16.10.5172.16.10.5

Which of the following actions will resolve the workstation's external network connectivity issue?

  1. Update the default gateway address to an IP address within the local 172.16.45.0/24172.16.45.0/24 subnet.Answer
  2. B
    Reconfigure the preferred DNS server address to 172.16.45.1172.16.45.1 to handle inter-subnet routing.
  3. C
    Replace the local switch with an unmanaged Layer 2 switch to forward traffic across subnets.
  4. D
    Change the IPv4 address to 169.254.45.110169.254.45.110 so the host can utilize APIPA for external routing.

Answer

Update the default gateway address to an IP address within the local 172.16.45.0/24172.16.45.0/24 subnet.
For a host to communicate beyond its local segment, its configured default gateway must be an IP address located within the host's own subnet. Since the host IP is 172.16.45.110/24172.16.45.110/24, its default gateway must be on the 172.16.45.0/24172.16.45.0/24 network (such as 172.16.45.1172.16.45.1). The configured gateway (172.16.44.1172.16.44.1) is unreachable without a local router interface, preventing off-subnet communication while allowing local ping traffic.

Step-by-Step Solution

1
Analyze host IP and subnet mask
The host IP is 172.16.45.110172.16.45.110 with mask 255.255.255.0255.255.255.0 (/24), defining valid local host addresses from 172.16.45.1172.16.45.1 to 172.16.45.254172.16.45.254.
Determines the local broadcast domain boundaries and valid IP ranges.
2
Compare Default Gateway IP to host subnet
The gateway is configured as 172.16.44.1172.16.44.1, which belongs to subnet 172.16.44.0/24172.16.44.0/24.
A default gateway must be a Layer 3 interface residing on the host's local IP subnet to receive local Ethernet frames.
3
Identify required remediation
Change the default gateway to a valid router interface address on the local subnet (e.g., 172.16.45.1172.16.45.1).
Allows local hosts to transmit non-local traffic directly to the local router interface.

Key Concept

Subnet Masking and Default Gateway Placement
Rate this question