To prevent hackers from attacking user devices or networks using MAC addresses, you can configure MAC addresses of untrusted users as blackhole MAC addresses to filter out such invalid MAC addresses. When receiving a packet whose source or destination MAC address is a blackhole MAC address on a device, the device discards the packet.
정답: A
설명: (Krdump 회원만 볼 수 있음)
문제 2
Fill in Blank As shown in the figure, when PE1 receives an ARP request packet, it forwards the packet to PE4. The packet then carries two labels. The label value 201 is carried by the EVPN Type ____ route. (Enter only digits.)
정답:
Understanding EVPN (Ethernet VPN) Label Allocation and ARP Handling Explanation: Understanding EVPN (Ethernet VPN) Label Allocation and ARP Handling 🔹 What Happens in This Scenario? 1️⃣ CE1 (192.168.1.1) sends an ARP request to discover the MAC address of CE2 (192.168.1.2). 2️⃣ PE1 receives the ARP request and needs to forward it over the EVPN fabric. 3️⃣ To send the broadcast ARP request across the EVPN network, PE1 forwards the packet to PE4 using BUM (Broadcast, Unknown unicast, and Multicast) forwarding. 4️⃣ PE4, as the Designated Forwarder (DF), forwards the ARP request to CE2. Role of Labels in EVPN VXLAN/MPLS Networks 🔹 EVPN uses BGP to distribute MAC/IP reachability information using different route types. ✅ EVPN Type 2 Route (MAC/IP Advertisement Route): Used for MAC-to-IP address mapping announcements. Ensures remote VTEPs (PE routers) learn MAC-to-IP bindings dynamically. ✅ EVPN Type 3 Route (Inclusive Multicast Route): Used for BUM traffic (Broadcast, Unknown Unicast, Multicast). Assigns a multicast label (e.g., 201) to be used for forwarding broadcast packets like ARP requests. 🔹 In this case: The label 201 is used for BUM traffic forwarding. BUM traffic is handled using an EVPN Type 3 route. Why is the Answer 3? ✅ EVPN Type 3 routes carry labels for BUM traffic, which includes ARP requests. ✅ Label 201 is used for multicast distribution, which is managed by Type 3 routes. Real-World Application: VXLAN Data Centers: Uses EVPN Type 3 routes to control BUM traffic efficiently. Campus Networks: Prevents unnecessary flooding of ARP requests across VXLAN domains. ✅ Reference: Huawei HCIE-Datacom Guide - EVPN BGP Route Types and Multicast Labeling
문제 3
Collecting information before a cutover helps you determine whether services are normal before and after the cutover.
정답: A
설명: (Krdump 회원만 볼 수 있음)
문제 4
What can be determined from the following figure?
정답: C
설명: (Krdump 회원만 볼 수 있음)
문제 5
Fill in Blank A VGMP packet is encapsulated with a UDP header and a VGMP header. By default, a VGMP packet uses UDP port _____.
정답:
Understanding VGMP (Virtual Gateway Management Protocol) Explanation: 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 the active and standby firewalls synchronize their states for high availability. 🔹 How Does VGMP Work? The Active and Standby firewalls exchange VGMP packets to maintain state synchronization. These packets are encapsulated within UDP for transport. The default 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 ensures failover between active and standby firewalls. Carrier-Grade Firewalls: Uses VGMP with HRP to achieve zero-downtime firewall redundancy. ✅ Reference: Huawei HCIE-Datacom Guide - VGMP and HRP High Availability Mechanisms
