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Huawei HCIE-Datacom study materials
Huawei HCIE-Datacom study resources

Huawei HCIE-Datacom: Datacom

Huawei HCIE-Datacom · Work through your exam, one topic at a time.

All guide sections

Datacom

What the Datacom domain tests

The Datacom domain covers the technologies used in a Huawei data network: routing (OSPF, IS-IS, BGP), MPLS and Segment Routing (SR-MPLS, SRv6), EVPN/VXLAN fabrics, IPv6, multicast, QoS, network security, and automated operations with iMaster NCE, NETCONF/YANG, and telemetry. HCIE-Datacom questions are scenario-heavy: you are given a topology, a business requirement, or a failure symptom and must choose a design, a configuration sequence, or a diagnosis. The lab exam tests whether you can build and repair the same concepts.

Core rules and concepts

  • Fix the underlay first. VXLAN needs IP reachability between VTEP loopbacks and an MTU that carries the 50-byte VXLAN overhead; a 1500-byte underlay will drop large frames.
  • BGP EVPN is the control plane. Type-2 routes carry MAC/IP bindings, Type-3 routes carry the IMET tunnel endpoint, and Type-5 routes carry IP prefixes for L3VPN. Route-target import/export must match.
  • SRv6 uses an IPv6 locator; the locator is advertised into the IGP, and SIDs are 128-bit instructions. TI-LFA provides fast reroute without RSVP-TE.
  • Automation is not optional: NCE templates, YANG models, and model-driven telemetry replace box-by-box CLI.
  • Security and QoS are applied at the fabric edge: ACLs, AAA, and traffic policing/queuing.

Worked example

Server A on Leaf-1 VLAN 100 cannot reach Server B on Leaf-2 VLAN 100, but both can ping local gateways. Loopbacks are reachable. In EVPN, Leaf-1 has a local Type-2 route for Server A, but Leaf-2's Type-2 route is absent. The cause is a route-target mismatch: Leaf-1 exports RT 100:100 and imports 200:200, while Leaf-2 does the opposite. EVPN accepts a route only when its export RT matches a local import RT, so the MAC/IP route is discarded. Correcting the RT policy restores the Type-2 route and the VXLAN data path.

Traps that cost marks

  • Treating VNI as VLAN ID: a VNI is a 24-bit overlay identifier; a VLAN is local.
  • Debugging data plane before EVPN route-targets and route types.
  • Forgetting underlay MTU for VXLAN.
  • Assuming Type-3 routes carry MAC addresses.
  • Changing iBGP next-hop behavior without understanding recursion.