Huawei H35-211_V2.5 Dumps Questions Answers

On Huawei OLTs, the standard QoS pipeline for upstream packets is: first perform traffic classification (identify flows), then marking (set CoS/DSCP as required), next apply traffic policing (rate-limit and color traffic), followed by congestion avoidance (AQM such as RED/WRED), and finally congestion management (queue scheduling/priority queuing). This ordered sequence ensures correct identification and marking before any rate enforcement, and that packets encounter AQM prior to scheduler-based dequeue.

In Huawei access network devices (such as MA5800, EA5800, and SmartAX series), the DHCP Option 82 (Relay Agent Information Option) feature is used to identify the source location of DHCP requests coming from users connected to access ports.

This helps the DHCP server assign IP addresses based on access topology information, such as slot, port, and VLAN IDs.

When Option 82 is enabled globally and within the VLAN service profile, and the port/service-port is configured to allow user-side packets to carry Option 82, the device processes incoming DHCP requests as follows:

If a user-side DHCP packet does not contain Option 82:→ The device automatically adds local Option 82 information (e.g., circuit ID, remote ID) before forwarding it to the DHCP server.

If a user-side DHCP packet already contains Option 82:→ The device removes (strips) the existing Option 82 field to prevent spoofing or inconsistent location data.→ Then it adds its own local Option 82 information (accurate relay agent data based on the device’s configuration).→ The modified packet is then forwarded to the DHCP server.

This ensures that only trusted network-side Option 82 data is passed along, maintaining accurate user-location binding for IP address management and security.

Therefore, the correct behavior is:

The access device strips the Option 82 field from the user packet and adds its own local Option 82 information.

References (Aligned with HCIP-Access V2.5 and Huawei Technical Documents):

HCIP-Access V2.5 Study Guide – “Huawei Campus Network Overview” Chapter, Section: DHCP Relay and Option 82 Mechanism

Huawei MA5800/EA5800 Configuration Guide – IP Service → DHCP Relay and Option 82 Configuration

Huawei Enterprise Networking Product Documentation: “Understanding DHCP Option 82 Processing”

Huawei Access Network Feature Guide, Section: Processing Policies of DHCP Packets with Option 82

Huawei access security recommends limiting MAC learn counts per port/VLAN, and using anti-MAC-spoofing bindings: either automatic (dynamic) bindings generated by the system or manual static MAC bindings to the service/port. Simply replacing a terminal is not a network-side mitigation method and is not listed as a protection measure.