Huawei H12-811_V2.0 Practice Exam Questions & Answers

This statement is true. ARP is a Layer 2 broadcast-based protocol used to resolve an IPv4 address into a MAC address within the same broadcast domain. If two PCs are connected to the same switch but cannot learn each other's ARP entries, one likely reason is an incorrect VLAN configuration.

For example, if PC1 and PC2 are placed in different VLANs, or if one interface is configured with the wrong access VLAN, ARP broadcast frames from one PC will not reach the other PC because VLANs separate Layer 2 broadcast domains. As a result, the ARP request will not be received by the peer, and the MAC address cannot be resolved. Other causes may also exist, such as incorrect IP addressing, port isolation, or security policies, but VLAN misconfiguration is a very common and valid cause in campus switching scenarios. HCIA-Datacom teaches that ARP communication depends on correct Layer 2 domain membership, and VLAN planning or interface configuration errors often directly affect host-to-host communication even when both hosts are physically connected to the same switch.

Option C is false. In this configuration, the NAT address group test contains the public address range 100.1.23.1 to 100.1.23.254, and the address group works in PAT mode. Port Address Translation allows multiple different intranet users to share the same public IP address while being distinguished by different transport-layer port numbers. Therefore, intranet users with different private IP addresses do not have to use different post-NAT public IP addresses.

Option A is true because 100.1.23.254 is included in the configured public address pool and can be used for source NAT. Option B is also true because NAT is enabled on GE0/0/2, so if user traffic does not leave through that interface, the NAT policy may not be applied and public access may fail. Option D is true because the configured source address range includes 192.168.1.100, which falls within 192.168.0.0 to 192.168.255.255. HCIA-Datacom teaches that NAT behavior depends on matching traffic, address pools, PAT or no-PAT mode, and the interface where NAT is enabled. This question mainly tests understanding of source NAT and PAT address-sharing behavior.

All four options are possible causes of FTP login failure, so the correct answer is A, B, C, and D.

Option A is correct because if the FTP server function is not enabled on the Huawei device, the device cannot provide FTP services and the client cannot log in. Option B is also correct because if the authorized directory is not specified for the FTP user, the user may not be able to complete login or access file services properly, depending on the FTP user configuration requirements. Option C is correct because an FTP user account must be configured with the required username and password; otherwise, authentication cannot succeed. Option D is also correct because if the network between the FTP client and the device is unreachable, the client cannot establish the FTP connection at all.

In HCIA-Datacom troubleshooting, FTP login failure is usually checked from four aspects: service enablement, user configuration, permission or directory authorization, and network connectivity. This question tests standard remote maintenance troubleshooting logic for file transfer services on Huawei network devices.

In IPv6, link-local addresses use the prefix FE80::/10. These addresses are automatically generated or configured for communication on the local link only and are not routed across Layer 3 boundaries. Therefore, among the given options, FE80::FA63:DBFF:FE9E:10 is the correct link-local address, making option C correct.

Options A and B belong to the Unique Local Address (ULA) space, which uses the prefix FC00::/7. These addresses are intended for private internal IPv6 networks, somewhat similar in purpose to private IPv4 address ranges, but they are not link-local addresses. Option D, which starts with 2001::, is a global unicast address, used for routable communication across IPv6 networks. HCIA-Datacom teaches that link-local addresses are essential in IPv6 because they are used for functions such as neighbor discovery, router discovery, and routing protocol communication on the local segment. Even when a device has global unicast addresses, the link-local address still plays an important role in normal IPv6 operation and protocol adjacency establishment.

A /27 subnet mask is 255.255.255.224, which means each subnet contains 32 IP addresses. The subnet increments in blocks of 32 in the last octet: 0, 32, 64, 96, 128, 160, 192, 224. The address 192.168.1.200/27 belongs to the subnet 192.168.1.192/27.

For this subnet, the network address is 192.168.1.192, the broadcast address is 192.168.1.223, and the valid host range is from 192.168.1.193 to 192.168.1.222. Therefore, 192.168.1.221/27, 192.168.1.193/27, and 192.168.1.222/27 are all valid host addresses in the same subnet and are reachable at Layer 2 without routing. That makes A, C, and D correct.

Option B is not correct because 192.168.1.192/27 is the network address of the subnet and cannot be assigned to a host by default. This question checks IP subnetting and the ability to identify valid hosts within the same broadcast domain.

A /28 subnet mask corresponds to 255.255.255.240, which means each subnet contains 16 IP addresses. The subnet boundaries in the last octet increase in steps of 16: 0, 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, and so on. The host address 192.168.1.147 falls within the subnet range 192.168.1.144 to 192.168.1.159.

In that subnet, the network address is 192.168.1.144, the usable host range is 192.168.1.145 through 192.168.1.158, and the broadcast address is 192.168.1.159. Therefore, option C is correct. Option D is the first usable host address, not the broadcast address. Option A is just another usable host address. Option B would be the broadcast address only for a /24 network, not for a /28. HCIA-Datacom requires learners to master subnetting because it is essential for IP planning, gateway deployment, route summarization, and troubleshooting Layer 3 communication issues in campus and enterprise networks.