A user in a home office is unable to connect to the internet. A technician asks the user to run the ipconfig command. Which of the following first octets immediately suggests an issue with the IP address?
Correct Answer: B
An IP address starting with the first octet "169" immediately suggests an issue, indicating that the device has been assigned an Automatic Private IP Address (APIPA). APIPA addresses are self-assigned by a computer or device when it's unable to obtain an IP address from a DHCP server, which is common in situations where the device is unable to connect to the network or the DHCP server is not functioning properly. The range for APIPA addresses is 169.254.0.1 to 169.254.255.254, and seeing an IP address within this range is a clear indicator of connectivity issues related to DHCP.
References:
* CompTIA A+ Core 1 (220-1101) Exam Objectives, specifically the networking domain that covers understanding and troubleshooting network connectivity issues, including the significance of IP address ranges such as APIPA.
* Knowledge of TCP/IP networking concepts, specifically the role of DHCP in network connectivity and the implications of an APIPA address on a device's ability to connect to the internet.