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:
* dhcp snooping enable
* 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.