H12-821_V1.0 Exam Questions

IGMP Snooping runs at the data link layer and is used to manage and control multicast groups, and solves the problem of multicast packets being broadcast on Layer 2.

Administrators can use the import-route command to introduce OSPF under different process IDs to each other.

RSTP mid-role port does not need to wait for the forwarding delay and can directly enter the forwarding state. If the edge port receives BPDU, the edge port will be reconfigured an...

The interface using Silent-Interface will not receive and send OSPF messages, but directly connected routes can be advertised to OSPF.

Stateful inspection firewalls use session tables to track active TCP sessions and UDP sessions, and the firewall security policy determines which sessions are permitted, and packet...

The deployment of port isolation technology in Ethernet can realize layer 2 interoperability and layer 3 isolation, making the network more flexible.

DDoS attack means that the attacker controls a large number of zombie hosts and sends a large number of carefully constructed attack messages to the target host, thereby causing th...

Class 7 LSAs are generally not allowed to be transmitted in the backbone area, but you can use the suppress-forwarding-address command to allow Class 7 LSAs to be transmitted in Ar...

In the MSTP protocol, each MSTI uses the RSTP algorithm independently to calculate a separate spanning tree.

If the two interfaces of the firewall are divided into the same area, then the data packet flow between the two interfaces does not need to be processed by packet filtering and wil...

By default, VRRP on Huawei AR routers runs in preemption mode.

The first 4 bits of the IP multicast address are fixed at 1110, corresponding to the high 28 bits of the multicast MAC address. Among the last 28 bits of the IP multicast address,...

A port in the Discarding state in RSTP will discard the received data frames, but it can maintain the MAC address table based on the data frames received by the port.

Inter-route selection rules, routes with high Local_Pref values take precedence.

Packet loss only occurs at the sending end of the message.

Because multicast data forwarding relies on routing table entries, problems such as loops and suboptimal paths will not occur during the forwarding process.

In the Trust zone view of the USG series firewall, after configuring add interface GigabitEthernet0/0/1, it no longer belongs to the Local zone.

In order to ensure that both systems know the status changes, BFD uses a three-way handshake mechanism when establishing and tearing down the BFD state machine.

When a switching device not running the MSTP protocol receives a configuration BPDU, it will be compared with the global configuration message sent by the device. If the newly rece...

If a service VLAN has set the VLAN Pool to a dual-stack address pool, STA will successfully obtain an IPv4 address and an IPv6 address.

In OSPF broadcast or NBMA network types, devices with high DR Priority may not necessarily become DR.

BFD itself does not have a neighbor discovery mechanism, but relies on the upper-layer application being served to notify its neighbor information to establish a session.

In the OSPF routing domain, in broadcast networks and NBMA networks containing at least two routers, one router must be designated as the DR and the other as the BDR.

BGP neighbor is a neighbor relationship established through UDP.

By default, in the VRP version, when the BGP neighbor ingress routing policy (route-policy) changes, refresh will be automatically sent to the neighbor to request the neighbor to r...

When there are two ACs and multiple APs in the WLAN network, to configure the network in master- backup mode, half of the APs plan AC1 as the main AC and AC2 as the backup AC, and...

The firewall at the Diff-Serv domain usually only needs to perform simple traffic classification.

In the multicast service model, the SSM model generates entries for each (S, G) information.

In the process of OSPF, if its Link Type is 1, the LSA describes the point-to-point link from this router to the neighbor router. At this time, the corresponding Link ID describes...

The ABR in the NSSA area will not flood Type 4 and Type 5 LSAs to NSSA, but will flood Type 7 LSAs to other areas.

EVPN is a VPN technology that can only provide layer 2 network interconnection.

The AC is a Level-2 router.

When the NE8000/NE40E/SLevel-1-2 router will publish the detailed routing information of the Level-2 area to the Level-1 area to ensure that the routers in the Level1-1 area can no...

In network A, the two DRother devices will not establish an adjacency relationship, and their status will remain in 2-way.

Whether the non-edge port migrates to the Forvardin state is one of the criteria for RSTP to detect topology changes.

The Discard port in RSTP can replace the failed root port.

For link state routing protocols, when using filter-policy import, the filtered link state information will not be calculated as routes, and its neighbors will not receive its link...

A typical NetStream system consists of two parts: the network stream data exporter NDE and the network stream data collector NSC.

There are multiple default security zones on the USG firewall. The Untrust zone and Local zone cannot be deleted by the administrator, but the Trust zone and DMZ zone can be delete...

In the BGP routing rules, the priority of the manual summary route generated by the aggregate command is higher than the automatic summary route generated by the summary automatic...

By default, VRP requires manual operation to resend update messages to the neighbor when the BGP command export routing policy (route-policy) is changed.

In dual-link hot backup, the AP will establish CAPWAP links with the main AC and backup AC.

Master eCE-Campus supports the management of Huawei network equipment through NETCONF and the management of third-party equipment through SNMP.

The modular switch only supports using the cluster card on the main control board to establish cluster connections, it means that the modular switch uses CSS2 stacking technology.

When a BGP routing policy changes, neighbors are notified through Notification messages. Only BGP devices that support route refresh capabilities will send and respond to this mess...

SSH uses asymmetric addition AES and DES to achieve data transmission security, and uses HMAC to ensure complete integrity verification of data.

Local_Pref is used as a metric value to indicate to external peers the preferred path into this AS. By default, the router compares the MED values of BGP routes from different ASs....

OSPFv3 uses the same route advertisement method as OSPFv2; it is advertised through the network command in the OSPFv3 area view.

IGMPv2 protocol messages are directly encapsulated by IP, with destination address 224.0.0.13 and IP protocol number 103.

IGMPV1 defines a mechanism for electing queriers when multiple routers exist in a shared network.