Pass the Huawei HCIA-Datacom H12-811_V1.0 Questions and answers with ExamsMirror

An IPv4 packet consists of a header and a payload:

Total Length=Header Length+Payload Length\text{Total Length} = \text{Header Length} + \text{Payload Length}Total Length=Header Length+Payload Length

Given:

IPv4 header length = 20B

Total packet length = 1500B

Payload=1500B−20B=1480B\text{Payload} = 1500B - 20B = 1480BPayload=1500B−20B=1480B

Option A (Incorrect): 1520B is incorrect because it exceeds the total packet length.

Option B (Incorrect): 20B is just the header, not the payload.

Option C (Incorrect): 1500B includes the header, not just the payload.

Option D (Correct): 1480B is the correct payload size.

Thus, the correct answer is D (1480B).

Detailed Explanation:

Option B: OSPF supports triggered updates, allowing routing tables to be updated only when changes occur, conserving bandwidth.

Option D: OSPF supports area division, which is essential for optimizing large networks and limiting the scope of link-state advertisements.

Option A is incorrect because OSPF calculates the shortest path based on cost, not hop count.

Option C is incorrect; OSPF prevents routing loops by maintaining a loop-free topology through its link-state database.

(Reference: HCIA-Datacom Training Material, OSPF Features)

In RSTP, an edge port is intended to connect directly to end devices, not other switches. However, if the edge port receives a BPDU, it will lose its edge status and revert to a standard STP port. This feature prevents loops by reconfiguring the port based on network conditions​.

Comprehensive Explanation: In STP (Spanning Tree Protocol), the root bridge is elected based on the lowest Bridge ID. The Bridge ID consists of two parts: the bridge priority and the MAC address of the switch. The switch with the lowest Bridge ID is elected as the root bridge. If two switches have the same priority, the switch with the lowest MAC address becomes the root. Other parameters such as Port ID and Root path cost are used in subsequent decisions to determine the best paths to the root bridge, but they are not used in the root bridge election itself.

When a Windows host first boots up and does not have an IP address, it sends a DHCP Discover message to find a DHCP server.

The source IP address of this packet is 0.0.0.0, meaning the host does not yet have an assigned IP.

The destination IP address is 255.255.255.255, which is a broadcast address.

Option A (Incorrect - 127.0.0.1): This is the loopback address, used for internal testing.

Option B (Incorrect - 169.254.2.33): This belongs to the APIPA (Automatic Private IP Addressing) range, assigned when a DHCP server is unavailable.

Option C (Correct - 0.0.0.0): The correct source IP for the initial DHCP Discover packet.

Option D (Incorrect - 255.255.255.255): This is used as the destination IP for broadcasting, not the source.

Thus, the correct answer is C.

Detailed Explanation:Making a call on a landline telephone involves network communication. Though it uses a traditional telephone network (Public Switched Telephone Network, PSTN), the process of sending and receiving voice data through a wired system qualifies as network communication. The voice signals are converted into electrical signals, transmitted over the network, and then converted back into voice signals on the receiving end .