Question

Difficulty: Very hardMobile Device Wireless and Network Connectivity

A field technician is troubleshooting a corporate mobile smartphone that cannot reach internal intranet sites or sync corporate email while connected to an enterprise Wi-Fi network. Inspecting the network configuration on the mobile device reveals an IP address of 169.254.112.45169.254.112.45. Additionally, the user notes that secure IMAP email synchronization fails when connecting over cellular data, and subscriber provisioning failed after transferring a physical SIM card from a deactivated legacy phone. Which TWO of the following actions should the technician perform to resolve these network and synchronization issues? (Select TWO.)

  1. Investigate and restore DHCP server reachability or scope availability on the wireless network segment.Answer
  2. Configure the mobile email client to connect using IMAP over port 993 with SSL/TLS enabled.Answer
  3. C
    Re-enter the legacy physical device's IMEI identifier into the cellular carrier management portal to activate the SIM card.
  4. D
    Switch the mobile email account configuration from IMAP to POP3 over port 110 to maintain status synchronization across devices.
  5. E
    Adjust the 2.4 GHz wireless access point radio channels to operate on Channel 4 to avoid wireless signal overlap.

Answer

The technician must restore DHCP server reachability on the wireless network segment to address the APIPA address assignment and configure the email client to use IMAP over port 993 with SSL/TLS encryption for secure email retrieval.
The presence of a 169.254.x.x169.254.x.x address indicates Automatic Private IP Addressing (APIPA), which occurs when the mobile device fails to contact a DHCP server; verifying DHCP service restores network access. Additionally, secure email synchronization using IMAP over SSL/TLS requires port 993, allowing encrypted message access while keeping mailbox states synchronized across endpoints.

Step-by-Step Solution

1
Diagnose the wireless network IP configuration issue
The IP address 169.254.112.45169.254.112.45 falls into the APIPA range (169.254.0.0/16169.254.0.0/16), indicating that the device's DHCP client request failed or timed out.
Resolving DHCP availability or pool exhaustion on the wireless network segment allows the device to receive a valid IP address, subnet mask, default gateway, and DNS configuration.
2
Correct the mobile email client security and port settings
Securing IMAP traffic with SSL/TLS encryption standardizes communication on TCP port 993.
Port 993 provides secure, encrypted email retrieval over public cellular networks while maintaining server-side folder state across multiple endpoints.

Key Concept

Mobile Wireless IP Addressing (APIPA) and Secure Email Synchronization Protocols
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