Huawei Updated H12-891_V1.0 Exam Questions and Answers by sulayman

To configure an SR-MPLS TE tunnel based on OSPF, all four options are mandatory:

A. Configure the LSR ID – LSR ID is required as the unique identifier of the router in MPLS and TE.

B. Enable segment routing in the OSPF process view – Needed to advertise segment information (SID).

C. Enable the opaque capability – Opaque LSAs are used to carry SR and TE information in OSPF.

D. Enable MPLS TE in the OSPF process view – Ensures that TE-related attributes (e.g., bandwidth) are advertised in OSPF LSAs.

Exact Extract - Huawei HCIE-Datacom SR-MPLS TE Configuration Guide:

“To support SR-MPLS TE over OSPF, it is necessary to configure the LSR ID, enable SR and MPLS TE capabilities in OSPF, and activate the OSPF opaque capability for carrying TE and SR attributes.”

BGP EVPN Route Types in VXLAN:

BGP EVPN Type 2 Route (MAC/IP Advertisement Route)

Used forhost reachability advertisement.

Carries MAC and IP address information of endpoints.

Does not carry an IP Prefix field(Type 5 routes handle prefixes).

Correct Explanation of Answer Choices:✅IP Address (B) is included– Used for host mobility and reachability.✅L3VNI (C) is included– Used forLayer 3 VXLAN routing.✅L2VNI (D) is included– Used forLayer 2 VXLAN bridging.❌IP Prefix (A) is not included in Type 2 routes– It is part ofEVPN Type 5 routesforprefix advertisement.

Reference from Huawei HCIE-Datacom Documentation:

Huawei VXLAN BGP EVPN Configuration Guide – Type 2 vs. Type 5 Routes

HCIE-Datacom Training Material – VXLAN Overlay Networks and BGP EVPN

Understanding VGMP (Virtual Gateway Management Protocol)

????What is VGMP?

VGMP (Virtual Gateway Management Protocol) is used in Huawei firewalls to manage hot standby (HRP - Hot Standby Routing Protocol).

Ensures that theactive and standby firewalls synchronize their statesfor high availability.

????How Does VGMP Work?

TheActive and Standby firewalls exchange VGMP packetsto maintain state synchronization.

These packets are encapsulatedwithin UDPfor transport.

Thedefault UDP port for VGMP is 512.

Why is the Answer 512?

✅Huawei firewalls use UDP port 512 by default for VGMP communication.

✅This ensures that VGMP heartbeats and synchronization messages are correctly processed.

Real-World Application:

Enterprise Firewalls:VGMP ensuresfailover between active and standby firewalls.

Carrier-Grade Firewalls:UsesVGMP with HRP to achieve zero-downtime firewall redundancy.

✅Reference:Huawei HCIE-Datacom Guide – VGMP and HRP High Availability Mechanisms

Understanding IRB (Integrated Routing and Bridging) Forwarding in VXLAN

VXLAN (Virtual Extensible LAN) supportsLayer 2 and Layer 3 forwardingbetween Virtual Network Identifiers (VNIs).

IRB (Integrated Routing and Bridging)enables inter-subnet communication within a VXLAN fabric.

There aretwo modes of IRB forwarding:

Symmetric IRB

Asymmetric IRB

Why the Answer is "Symmetric" IRB Forwarding?

✔Ingress VTEP performs both Layer 2 and Layer 3 lookups:

Symmetric IRBrequiresboth ingress and egress VTEPsto performLayer 3 lookups.

Theingress VTEP (source gateway) performs a Layer 2 MAC lookup, then aLayer 3 lookupto find the destination VTEP.

Theegress VTEP (destination gateway) performs another Layer 3 lookupbefore forwarding the packet to the destination.

✔Asymmetric IRB does not perform two lookups at the ingress VTEP:

In Asymmetric IRB,the ingress VTEPperforms both Layer 2 and Layer 3 forwardingandsends a Layer 2 packet to the egress VTEP.

Theegress VTEP only does a Layer 2 lookup, not a Layer 3 lookup.

Since thequestion states that both L2 and L3 lookups occur at the ingress VTEP,asymmetric IRB is incorrect.

✔Why Symmetric IRB is More Common?

Scalability:Supportsany-to-any communicationacross VXLAN networks.

More Efficient Routing:UsesLayer 3 VXLAN encapsulation, ensuring efficient routing between VNIs.

????Reference:Huawei HCIE Datacom – VXLAN Symmetric and Asymmetric IRB Forwarding