Hcie-Datacom Free Sample Questions

In an EVPN fabric, the Type 2 route is used to advertise the reachability of individual end systems (hosts). It carries both the MAC address and, optionally, the IP address of the host, allowing other VTEPs to learn these bindings. This is fundamental for forwarding both Layer 2 and Layer 3 traffic within the VXLAN overlay.

The m.get() method is used for retrieving operational state data, distinct from m.get_config() which retrieves configuration data. The correct approach is to use a subtree filter specifying the YANG model path to the desired operational data, in this case, the BGP peers. The XML filter needs the correct namespace to identify the YANG module.

The filter-lsa-out command, applied on an ABR within the area configuration, is the specific mechanism designed to filter Type 3 and Type 5 LSAs from being advertised into that area. This directly manipulates the LSA advertisement at the area boundary, which is more efficient than filtering routes after they have been calculated from the LSAs.

802.1X is the standard for port-based network access control, providing strong, credential-based authentication suitable for corporate employees.

Portal authentication (or captive portal) redirects users to a web page for login, which is ideal for guest access as it does not require any pre-configured client software.

MAC address authentication is used for devices that do not support 802.1X, such as printers or IoT sensors. It authenticates the device based on its unique hardware MAC address.

The SRGB is a locally significant range of labels that each router reserves for use by Segment Routing. Global SIDs, like Prefix-SIDs advertised by IGP, are mapped to a label within this block. For SR to function correctly, all routers in the domain should ideally be configured with the same SRGB range.

Huawei's SD-WAN solution uses a proprietary protocol, OMP (Overlay Management Protocol), not BGP, for the controller to distribute overlay routing, policies, and security information to the CPEs. While CPEs may use BGP to learn routes from the local site, the control plane communication with iMaster NCE-WAN is OMP-based.

Idempotency is a fundamental concept in automation and IaC. It means that applying an operation multiple times produces the same result as applying it once. In Ansible, an idempotent task will check the current state of the system and only make a change if the desired state is not already met. This prevents errors and ensures predictable outcomes.

Route Targets control the distribution of VPNv4 routes between VRFs. For PE2 to import routes from PE1, the export-rt value configured on PE1's VRF must match an import-rt value on PE2's VRF. A mismatch is a very common cause for VPN routes not being installed in the remote PE's VRF routing table, even when the MP-BGP session is up.

The ORIGINATOR_ID is a non-transitive BGP attribute created by a Route Reflector. It carries the Router ID of the BGP speaker that originally advertised the route into the AS. When another router receives this update, if it sees its own Router ID in the ORIGINATOR_ID attribute, it discards the update, thus preventing a routing loop.

Flexible Ethernet (FlexE) is a technology that decouples the MAC layer from the PHY layer, allowing for the creation of hard, isolated slices of a physical Ethernet interface. This provides deterministic bandwidth and latency guarantees, which is essential for the hard slicing required by some 5G services. It is a key component of Huawei's CloudWAN solution for network slicing.