Free H12-821_V1.0 Huawei Updates

Comprehensive and Detailed Step-by-Step Explanation:

Blackhole Route Issue in BGP:

In IBGP, the next hop of a route learned from an EBGP peer is not changed by default. If an IBGP peer cannot reach the next hop, blackhole routes may occur.

To prevent this, the peer next-hop-local command is used to set the next hop to the local router's IP address.

Other Commands:

peer mpls-local-ifnet: Used in MPLS networks to set the next hop as the local interface address.

peer private-nexthop: Allows advertising private IP addresses as the next hop.

peer next-hop-invariable: Ensures the next hop is not modified during route advertisement, which is the opposite of what is required here.

References:

HCIA-Datacom Study Guide, Chapter: BGP Next Hop Behavior

Huawei BGP Configuration Commands

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.

References:

HCIA-Datacom Study Guide, Chapter: DHCP Configuration and Troubleshooting

Huawei DHCP Relay Agent Configuration

 DIS and DR Election

The IS-IS Designated Intermediate System (DIS) is responsible for generating and updating pseudonode LSPs on a broadcast network.

Unlike OSPF DR, the IS-IS DIS does not preempt by default. This behavior avoids unnecessary flapping in the network due to frequent DIS re-elections.

 HCIP-Datacom-Core Reference

The characteristics of DIS and DR behavior are explained in IS-IS network operation chapters​​.

Comprehensive and Detailed Step-by-Step Explanation:

Interface ID in IPv6:

The interface ID is the last 64 bits of an IPv6 address, and it uniquely identifies an interface within a subnet.

It can be generated in three ways:

Manually Configured: Explicitly assigned by an administrator.

System-Generated: The operating system assigns a random or pseudo-random value.

EUI-64 Standard: Generated based on the MAC address of the interface.

Correct Statement:

IPv6 supports all three methods for generating interface IDs.

References:

HCIA-Datacom Study Guide, Chapter: IPv6 Address Structure

Huawei IPv6 Address Generation Methods

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