Pass Using H12-821_V1.0 Exam Dumps

A is false – The correct formula is: Skew_Time = (256 - Priority)/256 × Advertisement_Interval.

B is false – By default, the preemption delay is typically 0s , not 1s, meaning a higher-priority backup router can preempt immediately unless configured otherwise.

C is true – The default Advertisement interval in VRRP is 2 seconds .

D is true – The formula Master_Down_Interval = 3 × Advertisement_Interval + Skew_Time is correct.

Reference from Huawei HCIP-Datacom-Core Technology Study Guide:

“The VRRP Skew_Time is calculated as (256 - Priority)/256 × Adver_Interval. The Master_Down interval includes this Skew_Time to stagger failover.”

(Chapter: High Availability – Section: VRRP Timer Mechanism)

 GRE Characteristics

GRE does not inherently support encryption or authentication. It is a tunneling protocol for encapsulating packets, and data security features must be implemented using other protocols such as IPsec.

Other correct attributes of GRE include:

B. Supports multicast transmission.

C. Acts as a Layer 3 VPN encapsulation technology.

D. Can work with VPN protocols like IPsec for better security.

 HCIP-Datacom-Core Reference

GRE features and limitations are discussed in VPN encapsulation technology chapters​​.

 Transitive vs. Non-Transitive Attributes

The Community attribute is a transitive optional attribute , meaning that if a router receives a route with this attribute and does not understand its purpose, the router retains and propagates it to other peers.

Other options, such as AS_Path and MED, are well-defined mandatory or optional attributes with specific purposes.

 HCIP-Datacom-Core Reference

The behavior of optional transitive attributes is detailed in the BGP protocol and attribute chapters​​.

A Totally Stubby Area in OSPF is a special type of stub area where only intra-area (Type 1) LSAs , router LSAs , and default routes (Type 3 LSA with 0.0.0.0/0) are allowed to be injected. It blocks inter-area routes (Type 3 LSAs for specific prefixes) and Type 5 LSAs (external routes) to reduce the size of the Link-State Database (LSDB) and enhance router performance.

Explanation of the Options:

A. Type 3 specific LSA – ❌ Correct Answer . These LSAs represent inter-area routes. Totally Stubby Areas do not allow Type 3 LSAs for specific routes , only for the default route (0.0.0.0/0).

B. Type 1 LSA – ✅ Allowed. These are Router LSAs generated by routers within the area and are necessary for OSPF to function.

C. Type 3 LSA that describes a default route – ✅ Allowed. This is the only Type 3 LSA permitted in a Totally Stubby Area. It provides a default route (0.0.0.0/0) to reach external destinations.

D. Type 2 LSA – ✅ Allowed if there are broadcast or NBMA networks in the area. These describe the network segment in multi-access environments and are generated by the DR.

Official Huawei Reference:

???? Huawei HCIP-Datacom-Core Technology Study Guide –

Chapter: OSPF Special Areas

" A totally stub area does not allow inter-area Type 3 LSAs or external Type 5 LSAs to enter. Only a default route is injected in the form of a Type 3 LSA (0.0.0.0/0), which greatly reduces the LSDB size. "

???? Also refer to:

Huawei VRP Command Guide > OSPF > Configuration Notes > OSPF Special Areas