An industrial IoT controller installed in a warehouse facility on VLAN 12 (subnet ) fails to send telemetry data to the central management server. A network technician reviews the controller's active network settings via a serial console connection and observes the following configuration details:
IP Address: 10.120.12.45
Subnet Mask: 255.255.255.0
Default Gateway: 10.120.13.1
DHCP Server: 10.120.1.10
Which of the following root causes explains why the controller cannot communicate with servers outside its local subnet?
- The default gateway is configured on a different IP subnet than the host.Cevap
- BThe host assigned itself an APIPA address because the DHCP server was unreachable.
- CThe router interface connecting VLAN 12 lacks an IP helper address configuration.
- DThe IP address 10.120.12.45 represents the broadcast address for the assigned /24 subnet.
Cevap
The default gateway address (10.120.13.1) resides outside the local subnet (10.120.12.0/24) assigned to the host, preventing remote IP routing.
For IP routing to function, a host's default gateway address must belong to the same local IP subnet defined by the host's IP address and subnet mask. Here, the host is on 10.120.12.0/24 while the gateway is configured as 10.120.13.1. As a result, the host cannot send traffic off its local network.
Adım Adım Çözüm
Anahtar Kavram
Subnet Mask and Default Gateway Adjacency