Huawei H12-821_V1.0 - HCIP-Datacom-Core Technology V1.0

An IP prefix filter is designed to match both the IP address and its prefix length, making it suitable for filtering routing information rather than data packets. Options A and D are incorrect because IP prefix filters do not work directly on data packets, and they can match both prefix numbers and lengths ​.

When the level of an IS-IS interface is changed, the adjacency must be re-established because IS-IS adjacencies are formed based on matching levels (Level-1, Level-2, or both). Other changes, such as cost or hello intervals, do not disrupt the existing adjacency but might impact routing metrics or timing ​.

The information provided indicates that the configured query interval is 60 seconds, which applies to general queries. Group-specific queries are sent at a shorter interval, usually derived from the maximum response time. Therefore, the statement about a 60-second interval for group-specific queries is false. Other statements regarding maximum response time (10s), IP address, and IGMP version (V2) are correct ​.

Comprehensive and Detailed Step-by-Step Explanation:

Interface ID in IPv6:

Theinterface IDis the last 64 bits of an IPv6 address, and it uniquely identifies an interface within a subnet.

It can be generated in three ways:

Manually Configured:Explicitly assigned by an administrator.

System-Generated:The operating system assigns a random or pseudo-random value.

EUI-64 Standard:Generated based on the MAC address of the interface.

Correct Statement:

IPv6 supports all three methods for generating interface IDs.

IGP routes can be injected into BGP using multiple methods, not just thenetworkcommand. Theimport-routecommand can also be used to redistribute IGP routes into BGP. Thenetworkcommand requires the route to exist in the routing table, whileimport-routeallows direct redistribution ​.

Attributes such ascommunity,tag, andorigincan be directly referenced in theapplyclause of a route-policy. However,IP-prefixis not an attribute but a prefix list used for matching, and it cannot be directly applied ​.

Comprehensive and Detailed Step-by-Step Explanation:

1. What is L2TP (Layer 2 Tunneling Protocol)?

L2TP is a tunneling protocol used to transport Layer 2 frames over IP networks.

It is commonly used to establish VPNs but does not provide built-in encryption or security for the transmitted data.

2. Why L2TP Requires Additional Security Measures:

Since L2TP does not encrypt traffic, it is vulnerable to eavesdropping and tampering.

To secure L2TP tunnels, it is often paired with IPsec, which provides strong encryption and authentication. The combination of L2TP and IPsec is known asL2TP/IPsec.

3. Why the Statement is TRUE:

The statement accurately describes the limitation of L2TP (lack of encryption) and the need for additional security measures like IPsec.

The command output confirms that the VLANs with IDs 2 and 4 are part of the VLAN pool named "STA." The VLAN pool concept is used to allocate VLANs dynamically to devices or subnets, which reduces broadcast domain size and improves network efficiency. The total number of VLAN pools is unrelated to this output, and the assignment algorithm (hash or even) is not explicitly mentioned in the output. Huawei VLAN pool management references align with this analysis ​.

Edge ports are used in RSTP to bypass the spanning tree calculation for ports connected to end devices. By configuring ports like SWD's GE0/0/2 and SWC's GE0/0/2 as edge ports, they transition directly to the Forwarding state upon activation, ensuring faster convergence. Statement A is incorrect because receiving BPDU invalidates the edge port status ​.

Comprehensive and Detailed in-depth Step-by-Step Explanation:

In an Intermediate System to Intermediate System (IS-IS) network, aDesignated Intermediate System (DIS)is elected on broadcast networks to perform the following functions:

Represent the broadcast network as a pseudonode.

Generate and update the Link State Protocol Data Units (LSPs) for the pseudonode.

The DIS is elected based on theDIS priorityvalue, which is configured on IS-IS interfaces. If two routers have the same priority, the router with the higher MAC address becomes the DIS.

Thedefault DIS priorityfor IS-IS interfaces is64, which can be modified depending on the network requirements.

Option A (200):Incorrect. This is not the default value.

Option B (64):Correct. This is the default DIS priority value.

Option C (1):Incorrect. This is not the default value.

Option D (100):Incorrect. This is not the default value.