Huawei H12-891_V1.0 - HCIE-Datacom V1.0

Comprehensive and Detailed Explanation:

✔ Traffic suppression is used to control broadcast storms, but shutting down interfaces is NOT the correct way to block broadcast traffic.

✔ Correct Statements:

✅ (B) Intranet security covers both wired and wireless networks.

✅ (C) CAPWAP tunnels use DTLS encryption for security.

✅ (D) Wireless security requires air interface protection against attacks.

📖 Reference: Huawei HCIE Datacom – Intranet Security Design

In hot standby (active-active/load balancing) scenarios, Quick Session Backup is critical. This function ensures that session entries are immediately synchronized between firewalls to handle asymmetric traffic (where return traffic goes through a different firewall than the forward traffic).

Without it, the return packet may be dropped due to missing session information on the alternate firewall.

Exact Extract - HCIE-Datacom Security Module:

“When VGMP is in load balancing mode, quick session backup must be enabled to prevent traffic loss due to inconsistent forward and return paths.”

Option B is incorrect because it falsely states that EBGP cannot be configured on Spoke-PE or Spoke-CE if the Hub-CE and Hub-PE run IGP. In reality, EBGP can still be used between Spoke sites and PE devices, regardless of the protocol between the Hub PE and CE. EBGP is often used for PE-CE communication, including in Hub-and-Spoke architectures.

Exact Extract - Huawei HCIE-Datacom VPN Section:

“In Hub & Spoke deployments, EBGP can be deployed between Spoke-CE and Spoke-PE. The choice of routing protocol between Hub-CE and Hub-PE does not limit this.”

Understanding HTTP Security Risks

🔹 What is HTTP?

HTTP (Hypertext Transfer Protocol) is a protocol used for communication between web clients (browsers) and servers.

It is unencrypted, making it vulnerable to security threats.

Potential Risks in HTTP Communication:

✅ A. Eavesdropping (Data Interception)

Correct: HTTP traffic is unencrypted, meaning attackers can capture data using tools like Wireshark or MITM (Man-in-the-Middle) attacks.

Example: Hackers intercept login credentials over public Wi-Fi.

✅ B. Pretending (Impersonation / Spoofing)

Correct: Without encryption or authentication, attackers can spoof legitimate websites.

Example: A phishing website mimics a banking login page to steal user credentials.

✅ C. Tampering (Data Manipulation)

Correct: Attackers can modify HTTP data in transit, changing the content sent to users.

Example: Injecting malicious scripts into a webpage (e.g., Cross-Site Scripting - XSS).

❌ D. Lost (Low Probability of Data Loss)

Incorrect: HTTP runs over TCP, which ensures reliable data transmission.

Packet loss is not a major security risk but rather a network performance issue.

How to Mitigate HTTP Risks?

Use HTTPS (HTTP Secure) → Encrypts data using TLS (Transport Layer Security).

Enable HSTS (HTTP Strict Transport Security) → Forces HTTPS connections.

Implement Web Application Firewalls (WAFs) → Protects against attacks like SQL Injection & XSS.

✅ Reference: Huawei HCIE-Datacom Guide – Network Security Risks in HTTP Communication

In IPsec, a symmetric encryption algorithm (e.g., AES) is used for encrypting data due to its speed. To securely exchange the symmetric key between peers, asymmetric encryption algorithms (like RSA) are used.

This method ensures:

High performance (due to fast symmetric encryption)

Secure key exchange (asymmetric protection)

Exact Extract - Huawei HCIE-Datacom Guide – IPsec Encryption:

“IPsec uses symmetric algorithms to encrypt data for performance and asymmetric algorithms to securely exchange symmetric keys during IKE negotiation.”

BGP in Huawei SD-WAN

Huawei SD-WAN uses BGP (Border Gateway Protocol) as the primary routing protocol to exchange VPN routes between Customer Premises Equipment (CPEs) and the controller.

✅ Why BGP is Used in SD-WAN?

Scalability: BGP can handle a large number of VPN routes.

Policy-Based Routing: BGP allows traffic engineering and policy control across SD-WAN tunnels.

Multiprotocol Support: Huawei SD-WAN uses MP-BGP to exchange IPv4, IPv6, and VPNv4 routes.

Comprehensive and Detailed In-Depth Explanation:

The Huawei SD-WAN Solution uses HTTP/2 as the primary protocol to report device performance data to the controller.

HTTP/2 is chosen for its high efficiency, low latency, and enhanced data transfer speed.

It supports bidirectional communication between devices and the iMaster NCE-Campus controller.

While protocols like NetFlow and SNMP are traditionally used for monitoring, Huawei SD-WAN specifically uses HTTP/2 for real-time performance reporting and control due to its modern web-based architecture.

GRE (Generic Routing Encapsulation) has the following benefits:

B. VPN Construction — GRE is often used to build site-to-site VPNs.

C. ARP Encapsulation — GRE supports Layer 2 protocol encapsulation such as ARP.

D. Multicast Support — GRE tunnels can encapsulate multicast packets, unlike traditional IPsec.

A. Enlarging the hop limit is incorrect — GRE does not inherently change TTL or hop behavior; routing protocols still use standard IP processing.

Exact Extract - Huawei HCIE-Datacom Tunneling Chapter:

“GRE can encapsulate multicast and broadcast packets and supports L2 protocols like ARP. It is often used for VPN construction over the internet.”

MPLS Positioning in the TCP/IP Model

MPLS (Multiprotocol Label Switching) operates between the Data Link Layer (Layer 2) and the Network Layer (Layer 3).

✅ MPLS is protocol-independent and supports various network layer protocols (IPv4, IPv6, VPN, etc.) by using labels instead of traditional IP routing.

✅ How MPLS Works:

MPLS assigns labels to packets, allowing fast forwarding based on the label rather than a routing table lookup.

Supports Layer 3 VPNs (L3VPNs), Layer 2 VPNs (L2VPNs), and MPLS Traffic Engineering (MPLS-TE).

✅ Why MPLS is Between Layer 2 and Layer 3?

MPLS adds a label between the Layer 2 (Ethernet, PPP) and Layer 3 (IP) headers, effectively creating a separate forwarding mechanism.

Label Switching Routers (LSRs) forward packets based on labels instead of IP addresses, reducing processing time.

Reference from Huawei HCIE-Datacom Documentation:

Huawei MPLS Technology Guide – MPLS Architecture and Label Switching

HCIE-Datacom Study Material – MPLS Positioning and Functionality in TCP/IP

Comprehensive and Detailed In-Depth Explanation:

A. When planning paths based on bandwidth: Correct. The available bandwidth of each interface must be set in advance to allow path planning based on bandwidth requirements.

B. When planning paths based on delay: Correct. To plan paths considering delay, you need to deploy TWAMP (Two-Way Active Measurement Protocol) or iFIT (Intelligent Flow Information Telemetry) to measure the real-time delay on network links.

C. If the controller plans SR-MPLS Policy paths: Incorrect. The controller can plan primary, backup, and load-balanced paths, enabling traffic distribution across multiple paths.

D. Statically planned SR-MPLS Policy paths: Correct. You can manually configure load balancing for the primary path when planning the SR-MPLS Policy path statically.