Comprehensive and Detailed In-Depth Explanation:
Understanding DHCP Snooping and its Configuration
1. What is DHCP Snooping?
DHCP Snooping is a security feature that helps prevent rogue DHCP servers from providing false IP configurations to clients.
It classifies switch ports as either:
Trusted (allowing DHCP replies from legitimate DHCP servers or relay agents).
Untrusted (blocking unauthorized DHCP responses from clients or attackers).
Analysis of the Commands
✅ A. [SW3-GigabitEthernet0/0/2] dhcp snooping enable (Required)
Interface GigabitEthernet0/0/2 is connected to a DHCP client (PC2).
DHCP snooping must be enabled on this interface to filter DHCP messages and prevent rogue DHCP servers.
Since PC2 is a client, this port should remain UNTRUSTED.
✅ This command is required.
❌ B. [SW3] dhcp snooping enable ipv4 (Not Required - Correct Answer)
The correct command to enable DHCP Snooping globally on Huawei switches is:
There is no need to explicitly specify ipv4 since DHCP is inherently an IPv4-based protocol.
❌ This command is unnecessary, making it the correct answer.
✅ C. [SW3-GigabitEthernet0/0/3] dhcp snooping trusted (Required)
GigabitEthernet0/0/3 is connected to the DHCP relay agent, which forwards DHCP messages between clients and the DHCP server.
This port must be configured as "trusted" to allow DHCP responses from the relay or the DHCP server.
✅ This command is required.
✅ D. [SW3-GigabitEthernet0/0/1] dhcp snooping enable (Required)
GigabitEthernet0/0/1 is connected to a DHCP client (PC1).
Similar to Port 0/0/2, DHCP snooping must be enabled on this interface to filter DHCP messages and prevent rogue DHCP responses.
✅ This command is required.
Final Conclusion:
✅ A. Required (PC2’s port needs DHCP snooping enabled).❌ B. Not required (Incorrect command syntax, ipv4 is unnecessary).✅ C. Required (Port connected to DHCP relay must be trusted).✅ D. Required (PC1’s port needs DHCP snooping enabled).
Thus, the correct answer is: B. [SW3] dhcp snooping enable ipv4.
[Reference:, HCIP-Datacom-Advanced Routing & Switching Technology V1.0 – DHCP Snooping Configuration and Security Mechanisms, Huawei Official HCIP-Datacom Study Guide – DHCP Snooping on L2 and L3 Switches, Huawei Documentation on Configuring DHCP Snooping in Enterprise Networks, , , ]
