Examkin

Soru

Zorluk: OrtaMobile Device Wireless and Network Connectivity

A field employee working at a remote site connects a smartphone to a temporary wireless access point. Although the device shows a active Wi-Fi connection, the user cannot load internal company web applications or reach external network resources. Upon inspecting the IP settings on the smartphone, a technician observes an IP address of 169.254.112.45 with a subnet mask of 255.255.0.0. Which of the following is the most likely cause of this connectivity issue?

  1. The smartphone failed to contact a local DHCP server and automatically generated an APIPA address.Cevap
  2. B
    The access point was configured on Wi-Fi channel 2, causing co-channel interference with adjacent 2.4 GHz wireless networks.
  3. C
    The cellular service provider disabled data access because the device IMEI was registered instead of the SIM card IMSI.
  4. D
    The smartphone's secure email client attempted to synchronize incoming messages using unencrypted POP3 over port 443.

Cevap

The smartphone failed to contact a local DHCP server and automatically generated an APIPA address.
When an OS is set to receive IP configuration automatically via DHCP but receives no response from a DHCP server (due to server offline status, VLAN misconfiguration, or exhaustion of the IP pool), IPv4 link-local addressing (APIPA) automatically assigns an IP in the 169.254.0.1 through 169.254.255.254 range. Because an APIPA address lacks a default gateway, the mobile device cannot communicate with resources outside the immediate local network segment.

Adım Adım Çözüm

1
Analyze the IP address observed on the mobile device.
The IP address 169.254.112.45 belongs to the 169.254.0.0/16 address space.
This specific IPv4 range is reserved by IANA for Automatic Private IP Addressing (APIPA).
2
Identify the mechanism that assigns APIPA addresses.
APIPA is activated when a network client configured for DHCP cannot communicate with or receive an IP lease from an active DHCP server.
The client self-assigns a link-local address to enable communication only with other hosts on the immediate local segment.
3
Determine the root cause of the lack of network and internet access.
Because APIPA addresses are non-routable, the smartphone cannot communicate beyond the local broadcast domain or reach the internet/corporate network.
The inability to reach a DHCP server prevents the device from obtaining a valid gateway address and routable IP address.

Anahtar Kavram

APIPA Address Assignment and Mobile DHCP Troubleshooting
Bu soruyu puanla

Konular

Mobile Device Wireless and Network Connectivity

Bu konudan daha fazla soru