Huawei Updated H12-821_V1.0 Exam Questions and Answers by nyra

Comprehensive and Detailed Step-by-Step Explanation:

DHCP Configuration Issues:

Option C: The DHCP function is disabled by default on Huawei devices. If the administrator forgets to enable it, clients cannot receive IP addresses.

Option D: DHCP uses broadcast messages, which do not traverse routers. If the clients and DHCP server are on different subnets, a DHCP relay agent must be configured.

Other Options:

Option A: Multiple DHCP servers can coexist as long as their IP address pools do not overlap. This is unlikely to cause the problem.

Option B: STP does not affect DHCP operations unless it delays port activation, which is uncommon in this scenario.

Comprehensive and Detailed In-Depth Explanation:

Neighbor Discovery Protocol (NDP) replaces ARP in IPv6 and uses ICMPv6 messages for:

Router Solicitation (RS) → Sent by hosts to request Router Advertisement (RA) messages .

Router Advertisement (RA) → Sent by routers to announce prefixes and network parameters.

Neighbor Solicitation (NS) → Used for address resolution and Duplicate Address Detection (DAD) .

Neighbor Advertisement (NA) → Sent in response to NS messages .

Redirect → Used by routers to redirect hosts to better gateways .

RS is not directly used for address resolution ; Neighbor Solicitation (NS) does this , so the answer should be D .

???? Reference: Huawei HCIA-Datacom Study Guide, NDP and ICMPv6 Packet Types.

Comprehensive and Detailed In-Depth Explanation:

Type 7 LSAs (NSSA External LSAs) are used in Not-So-Stubby Areas (NSSAs) to carry external routing information.

These LSAs are generated only by ASBRs within an NSSA , and later converted to Type 5 LSAs by the ABR .

Stub areas do not allow ASBRs , meaning Type 7 LSAs cannot exist in a stub area .

The question incorrectly states that Type 7 LSAs can be generated in stub areas , which is false .

???? Reference: Huawei HCIA-Datacom Study Guide, OSPF LSA Types and Area Configurations.

BGP routes have a variety of path attributes that describe their characteristics and influence route selection. These attributes include well-known mandatory attributes like AS-PATH and NEXT-HOP, as well as optional attributes like MED and LOCAL_PREF.

In Huawei devices, there is a Huawei-specific attribute called " preference " , which is a local parameter used to influence BGP route selection on the device.

Key Characteristics of " preference " :

It is valid only locally on the router.

It is not shared with BGP peers.

It helps the router determine the best route when multiple routes exist for the same prefix.

It appears in the BGP routing table output in lowercase as preference.

Thus, the correct answer is preference (entered in lowercase as required).