80. A network technician is working on a PC with a faulty NIC. The host is connected to a switch with secured ports. After testing the connection cables and using a known-good NIC, the host is still unable to connect to the network. Which of the following is causing the connection issue?
Answer: A
The MAC address of the new card is causing the connection issue.
The issue with the network connectivity arises from the MAC address of the new NIC, which likely does not match the security settings of the switch ports to which the host is connected. This mismatch prevents the switch from allowing the new NIC to communicate on the network.
A) MAC address of the new card
This option is correct because many managed switches have port security features that restrict access based on the MAC addresses of connected devices. If the new NIC has a MAC address that is not recognized or permitted by the switch's configuration, the connection will be blocked, leading to the observed connectivity issue.
B) BPDU guard settings
This option is incorrect because BPDU guard is a feature used to protect the network from loops by disabling ports that receive Bridge Protocol Data Units (BPDUs) on access ports. If BPDU guard were the issue, it would suggest a spanning tree protocol problem, which is not relevant in this scenario since the connection is simply not being established due to MAC address restrictions.
C) Link aggregation settings
This option is also incorrect. Link aggregation settings involve combining multiple network connections to increase bandwidth and provide redundancy. Since the problem is with a single NIC and its interaction with the switch's security policies, link aggregation is not a factor contributing to the connectivity issue.
D) PoE over power budget
This option is incorrect as well. Power over Ethernet (PoE) issues relate to the amount of power that can be delivered to devices such as IP cameras or phones, rather than connectivity problems with a NIC. A faulty NIC would not be affected by PoE power budget limits in the context of establishing a network connection.
Conclusion
The correct answer is A because the MAC address of the new NIC must be recognized and allowed by the switch's port security settings to establish a successful connection. The other options fail to address the core issue of the network technician's inability to connect the host, which is specifically tied to the MAC address restrictions imposed by the switch.