H12-891_V1.0 HCIE-Datacom V1.0 Question and Answers

A AS_PATH attribute is used between autonomous systems to prevent ring cats.

The Cluster List property is used for reflector cluster inner ring defense, and the router finds that the Cluster List of route entries contains its own Client lD The route is rejected

Routes learned from IBGP are not advertised to IBGP neighbors and are used to prevent routing loops inside the AS

You can use the AS_CONFED_SET attribute to prevent loops within a consortium:

When using IPsec active-standby link redundant backups to enable the URPF function under the physical interface , it is recommended to use URPF loose mode.

When using IPsec multilink redundant backup, the URPF function can be used under the physical interface, and URPF strict mode can be used

When using IPsec multilink redundant backups, urPF can be enabled under the tunnel interface, and URPF strict mode can be used

When using lPsec active-standby link redundancy backup, the URPF function is enabled under the physical interface, and URPF strict mode can be used.

MASTER DOWN = (3*ADVER_ INTERVAL) + Skew_ time

Skew Time= (255-Priority)/255

By default, the time period for VRRP advertisement messages is 2 seconds

By default, the VRRP preemption delay is I seconds

Alternative port, Backup port

Backup port, root port

Root port, Designated port

Backup port, Alternative port

The IS-IS protocol is a link-state protocol that runs between AS

The IS-IS protocol supports CLNP networks

Messages for the IS-IS protocol are encapsulated directly by the data link layer

The IS-IS protocol supports IP network ad

True

False

Host Information Collection

Local ARP agent

port isolation

ARP broadcast suppression

True

False

RPF check failure indicates that the multicast data packets are received from a suboptimal interface, but the interface still receives multicast traffic and forwards it downstream

IGMP snooping function can not control the range of multicast traffic in the Ethernet flood

In the multicast transmission mode, the destination address of the message can specify the location of the receiver

The source address of the multicast message is the unicast address

The wrong BGP packet was received.

The mandatory attribute in the route update packet is missing.

Open message negotiation failed.

After the BGP connection is established, the keepalive message is not received within the negotiated holdtime time.

True

False

The ingress PE changes the IPv4 route received by the CE to the VPNv4 route, and the storage

PE is carried out according to different VPN instances What interacts with the CE is IPv 4 routing information

After receiving the VPNv4 route issued by the ingress PE, the egress PE filters the VPNv4 route according to the RT attribute carried by the route

The egress PE can send an IPv4 route to the remote CE via BGP, IGP, or static routing

Allows the peer PE to decide which VPNv4 routes to import into a particular VRF

Allows peer PE to decide which VPNv4 routes not to import into a particular VRF

Allows the peer CE to decide which VPNv4 routes to import into a particular VRF

Allows the peer CE to decide which VPNv4 routes not to import into a particular VRF

The tunnel between VXLAN Layer 2 and Layer 3 gateways is an IPv4 network.

IPv6 over VXLAN solves the problem of insufficient IP address resources for end tenants.

IPv6 Over VLANs do not generate ND table entries.

IPv6 over VXLAN means that the Overlay network of the VXLAN is an IPv6 network.

Destination port number

Source address

Destination address

Source port number

True

False

Copy IPTIL value is handled in such a way that the LSR of the MPLS domain is hidden, which plays a certain security role

Can prevent wireless circular forwarding of messages

MPLS has two ways of handling TTL, one is that the IP packet copies the PTTL of the MPLS header hen it enters the MPLS network Value; Another is to set the TTL of the MPLS header to 255 at the entrance LER

When copying TTL is disabled, tracert can see the LSR of the passing MPLS domain

Mac address spoofing attacks cause the switch to learn the wrong mapping of Mac addresses to IP addresses

A MAC address spoofing attack causes the data that the switch is sending to the correct destination to be sent to the attacker

MAC address spoofing attacks primarily exploit the switch Mac address learning mechanism

An attacker can perform a MAC address spoofing attack by sending a forged source Mac address data frame to the switch

R2 does not enable OSPFv3 on the loopback port

R2 does not advertise the loopback address

R2 in area 0 to advertise the loopback into a different OSPFv3 process

R2 does not configure the Router ID used in the OSPFv3 process

True

False

The router will have an EBGP BGP neighbor from it must be connected directly, otherwise, IBGP-Multi-hop must be configured

The router sends BGP updates learned from its EBGP neighbors to its other IBGP neighbors and EBGP neighbors

IBGP neighbors can establish neighbor relationships through the Loopback interface

The router sends BGP updates learned from its IBGP neighbors to its other IBGP neighbors and EPGP neighbors

EBGP neighbors must be directly connected, otherwise, EBGP-Multi-hop must be configured with

You can avoid the Eth-Trunk interface from frequently shaking interface eth-trunk 1l lacp preempt enable lacp preempt delay delay-time with the following command

Source IP address load sharing, interface eth-trunk1Load-balance src-dst-ip, can be configured in an enabled link aggregation group with the following command

The member interface can be removed from an enabled link aggregation group with the following command: interface GigabitEthemeto/0/1 Shutdown nterface Gigabithemet/O/1undo eth-trunklinterface GigabitEthemet0/0/1 undo shutdown

A chain cluster that can be initiated through an order Join the member interface :interface GigabitEthemeto/0/1 shutdown interface igabitEthemetO/0/1 tunkportGigabitEthermet0/0/1 interface GigabitEthermet0/0/1 Undo shutdown

R1 specifies that the peer R3 sets the MED property to 150 in the import direction

R2 specifies that the peer R1 sets the local priority to 150 in the export direction

R2 specifies that the peer R1 sets the MED property to 150 in the export direction

R1 specifies that the peer R2 beats the local priority in the import direction to 150

No configuration is required

Publish default routes only in the OSPF process for R2

In the OSPF process of R2 and the IS-IS process, the default routes are published separately

Publish the default route only in the IS-IS process of R2

TRUE

FALSE

2 ?LSA

3 ?LSA

1 ?LSA

5 ?LSA

4 ?LSA

Provides some low latency

Avoid TCP global synchronization

Avoid congestion completely

Provides a small bandwidth guarantee

Can avoid UDP occupying most of the bandwidth when congested

Without changing the current configuration, GigabitEthernet1/0/1 and GigabitEthernet1/0/2 can join the same aggregation group

Because of the different VLANs allowed, GigabitEthernet1/0/1 and GigabitEthernet1/0/2 cannot join the same aggregation group

After link clustering is configured on both SWA and SWB, if MSTP is enabled on the switches SWA and SWB Both GigabitEthernetl1/0/1 and GigabitEthernetl/O/2 are the forwarding status of MSTP

Only if the configuration of GigabitEthernet 1/0/2 is changed to match GigabitEthernet 1/0/1 can the two join the same aggregation group

CE accesses the backbone through two links that can be used as both load sharing and primary and standby links.

CE and PE form a CE dual-home network, which can ensure high network availability.

VRFs of two PEs connected to the same CE can belong to different VPNs.

In the CE dual home network, it is possible to generate loops, and you can use route-tag to solve the loop problem.

TRUE

FALSE

Cluster_List is an optional non-staging property for ring protection within the cluster.

The route learned from the client, all non-clients and clients published to this RR.

A network of bones is divided into multiple reflection clusters, each of which configures the other RRs as non-clients, and establishes an IBGP full connection between the RRs.

The Originator_ID attribute is generated by the Route Reflector (RR) for inter-cluster ring protection.

GEO/0/1 on ASWB is Alternative port

GE0/0/2 on SWB is Alternative port

SWA On GEO/0/1 for backup port

SWB will become the root bridge

The Principal VLAN can communicate with all VLANs within the MUX VLAN

Each Separate VLAN must be bound to a Principal VLAN

Separate VLANs can communicate with all VLANs within a MUX VLAN

Each Group VLAN must be bound to a Principal VLAN

The A. Advertising Router report is set to as the Router ID of ASBR

Net Mask is set to all 0

Link State lD is set as the destination network segment address

Using the Link State ID and Advertising Router, you can uniquely identify an LSA

iBGP-Multi-hop is not configured

Authentication is unsuccessful

IGP routing is not passable

BGP protocol version inconsistencies

The Option field of the Hello and DD packets extends to 24-bit

LSR packets containing the full LSA header information for requesting an update to the LSA

The LSACK message contains LSA header information to confirm receipt of the LSU message

The Hello message must contain the interface ID of the sending interface

TRUE

FALSE

Digital signatures guarantee the integrity of digital certificates.

Digital certificates contain public key information.

Authentication fails when the peer certificate is received within the validity period, but the device itself is in the wrong time if it is not within the validity period of the certificate.

Even if two PRI entities are not in the same CA system, authentication can be completed as long as both parties can recognize each other's CA.

TRUE

FALSE

Turning on root protection on the root port takes effect

The port that turns on the root protection receives the RST BDPU with a higher priority and will enter the error-down state

It is recommended that you turn it on on a switch that is at the edge of the network

After opening the root-protected port and receiving the RSTBPDU with a higher priority, if it does not continue to receive the RSTBPDU with a higher priority for a period of time, it will return to the normal forwarding state

Inter-AreaPrefix-SA's LinkStatelD contains the prefix

Router-LSA and Network-LSA does not contain routing information

When the Intra-AreaPrefixLSA's ReferencedLinkStateType-2, referencedLinkStatelD contains the interface to DR ID

Inter-AreaPrefirLSA also contains LinkLocal information file

IPv6 multicast does not contain MSDP and dense mode

The first 8bit IPV6 multicast address is always FF(11111111).

IPv6 multicast clients use IGMPv3 to join multicast groups

IPv6 multicast load sharing extends the multicast routing rules and is completely independent of RPF check

If the RI's Ethernet0/0/0 interface goes down, R2 becomes the master device

If the Ri's Ethernet0/0/1 interface goes down, R2 becomes the master device

If R3's G E0/0/0 interface goes down, R2 becomes the master device

If R3's Ethernet0/0/0 interface goes down, then R2 becomes the master device

MED default value is 100

MED can only be passed within this AS

MED is an optional non-transitional attribute

MED The default value is 0

The system distinguishes between static BFD sessions and dynamic BPD sessions by dividing the identifier area Dynamically assign this landmark identifier

BFD sessions can only be established dynamically

Static configuration of BFD session refers to manual configuration of BFD session parameters through the command line, including local identifiers and remote identifiers

TRUE

FALSE

Provides a built-in policer to limit the maximum available bandwidth of a low-latency queue during congestion

The parameter should be as small as possible. It means that the bandwidth is always preserved, and even if the LLQ is set, changing the parameters will reduce the available bandwidth of the interface

It represents a reference CIR to calculate the burst size D of the built-in tactician token bucket Changing parameters is an option because LLQ always takes precedence over other queues

which needs to be used in conjunction with route ingestion, acts as an external route sender neighbor that only partially introduces.

If you do not configure this command, the device will by default introduce the external routing protocol to the IS-IS route all outgoing

Restricts the external publication of route entries generated by the device itself

This command will filter the link status information released to the outside world

The Link State ID of inter-area prefix-SA, which contains prefix information

Router-LSA and Network-LSA do not contain routing information

When the Referenced Link State Type-2 of the Intra-AreaPrefixLSA, referenced Link State ID Contains the interface ID of the DR

Inter-Area PrefirLSA also contains LinkLocal Information

The transmission of Syslog messages is not secure

The transmission of Sysiog messages is reliable

The transmission of Syslog messages is confirmable

The transmission of Syslog messages is secure

The transmission of Syslog messages is not acknowledgable

The transmission of Syslog messages is unreliable

Alignment error

FCS error

Super Small Frame

Excess Conflict

Lag conflicts

The MP_UNREACH_NLRl of the update message, excluding the path nationality.

MP-BGP can be used to assign tags.

MP_REACH_NLRI and MP_UNREACIH_NLRI are optional transition properties.

A complete MP_REACH_NLRI attribute structure contains address family, next hop, and prefix information.

IPv6 unicast address is called a tentative address after it is assigned to an interface and before it is detected by duplicate addresses

Duplicate address detection is implemented via RS and RA messages

IPv6 duplicate address detection technology is similar to free ARP in IPv4

The interface needs to perform duplicate address detection before enabling any of the unicast IPv6 addresses

All members of the group and the multicast sources that send multicast data to the group converge to the unique RP

The initial multicast streams for all groups in the shared tree are forwarded to the receiver via RP

An RP can serve multiple multicast groups at the same time, a multicast group can correspond to multiple RPs

RPs can be responsible for the forwarding of several or all multicast groups, and there can be an RP in the network

CPU utilization is high and loops are easy to generate

Slow convergence and low CPU utilization

Fast convergence and low CPU utilization

Fast convergence and high CPU utilization

Prefixes are learned through other IBGP neighbors, or prefixes are learned from EBGP neighbors, or prefixes are learned through routing introduction

A prefix that exists in the routing table

Prefixes are learned through other BGP neighbors, or prefixes are learned locally through network or routing introduction

Prefixes are learned through EBGP neighbors, or prefixes are learned locally through network or routing introduction

The prefix is learned through an EBGP neighbor, or the prefix is learned from an from RR

True

False

True

False

ESP + tunnel mode

AH + transmission mode

AH + tunnel mode

None of the above options are correct

Neither the Stub region nor the NSSA region allows injection of Type4 LSA

Type5 LSA injection is not allowed in the Stub region, while Type5LSA injection is allowed in the NSSA region

Type7LSA injection is not allowed in the Stub region, while Type7LSA injection is allowed in the NSSA region

Both the Stub region and the NSSA region allow injection of Type3 LSA

RD routers use FF02: :6

The DR router uses FF08::6

All OSPF routers use FF02::5

Router HW's next hop router does not have a path to the destination address

Ping is successful, but congestion occurs on the path to the destination address

ICMP packets can reach the destination address But the destination device failed to reply

Router HW does not have a legitimate route to the destination address

There is a firewall in the remote destination network, and no ICMP traffic is allowed

MAC address

Health status

Stack priority

Stack ID

Memory that occupies the cache ton

Increases the power consumption of the power supply

Consumes a TCAM table entry

Consume the available bandwidth

Consume the MAC address table entry available in the system

ISIS ?Level-1 ?SNP ?LSP?

ISIS ?Level-2 ?SNP ?LSP?

Hello message of ISIS's Level-1.

Hello message of ISIS's Level-2

True

False

The BPDU interval between switches is not configured

The Transition VLAN mapping between the handover machines is not configured to be caused

The Revislon Level configuration is inconsistent between switches

Inconsistent Registry Name configuration between text exchange machines

True

False

True

False

The DSCP value can be 0, and packets use the default forwarding mechanism when 0

When the value of DSCP is EF, it indicates that the data belongs to the accelerated forwarding class.

In addition to indicating the priority of the data, DSCP can also indicate the probability of data being discarded. The CS class in D. DSCP divides data into 8 priorities.

R2, as DIS, sends CSNP periodically.

R2 As DIS, Hello time is 3 times that of a normal router . C. R2 as DIS does not receive PSNP nouns for other routes.

RI and R3 maintain database consistency by periodically sending PSNP requests.

In the case of sharing a single router, each OSPFV3 process runs independently

In the same OSPFv3 process under the same interface, you can run multiple instances of

You can support running multiple instances on a single link

OSPFv3 message header will contain the Instance ID field

RD can be used to control the publication of VPN routing information

On a PE device, each VPN instance corresponds to an RD value, and the RD value must be unique on the same PE device

RD is encapsulated in the Update message as an extended community attribute of BGP during delivery

After the PE receives an IPv4 route from CE, it adds an RD to the route to IPv4 that translates to a globally unique VPN-IPv4 route and publishes it on the public network

True

False

300 4200

1234 1400

3100

100

Virtual connections cannot traverse the Stub region

Backbone zones cannot be configured as Stub zones

ASBR cannot exist in the Stub zone

Type7 LSA injection is not allowed in the Stub zone

The interface ID of the sending interface must be included in the A Hello packet

The LSACK message contains LSA header information to confirm the receipt of LSU packets

The LSR message contains the complete LSA header information for requesting an update to the LSA

Hello messages and the Option field for DD messages extends to 24-bit

The route entry in the peer BGP route table is non-optimal.

The next hop address of the

BGP route entry is unreachable

Peer ignore is configured on the peer

The peer is configured with active-route-advertise

Enable DHCP snooping to check the chaddr field in a DHCP request message

Configure the trusted/untrusted interface

Configure DHCP snooping on the switch to interbolde with DAI or IPSG

Limit the maximum number of MAC addresses allowed to be learned on the switch interface

Under no circumstances can different sites that belong to the same VPN use overlapping address spaces

Two geographically separated networks must belong to different sites

Terminals connected to the carrier network through the same CE may belong to different sites

A site is a set of IP systems, and a network of hosts cannot be called site

By default, LSRs are for the same FEC, and the received tag mappings can only come from the optimal next hop, not from the non-optimal next hop.

When a network topology change causes the next hop neighbor to change, the free label keep method is used. LSR can quickly rebuild the LSP by directly using the labels sent by the original non-optimal next-hop neighbor. Liberal needs more memory and tag space.

In the DoD mode of label publishing, for a specific FEC, the LSR does not need to obtain a label request message from upstream to distribute the label.

The process of establishing a D. LSP is actually to bind the FEC to the tag and advertise this binding to the LSP upstream LSR process.

The router-LSA data area contains the Link-Local address

The router-LSA data area contains the Interface ID of the neighbor on this side

Similar to OSPFv2, the Option field exists in the header of LSA, not in the data area of Router-LSA

When LS type= Ox0001 in the head of LSA, the data area representing LSA is Router-LSA

Any routing information from an IBGP peer is advertised to the other IBGP peers

Any update information received from the EBGP peer that contains its own AS number in the AS-PATH attribute is discarded via the AS-PATH attribute

Non-RR BGP routers do not announce any updates from IBGP peers to other IBGP peers

BGP routers do not announce any slaves The EBGP peer comes to update the information to its EBGP peer

When both parties receive a keepalive message from the peer, the LDP session is successfully established

Hello messages discovered by LDP neighbors use TCP messages with a destination address of multicast address 224002

After the TCP connection is successfully established, the active party sends an initialization message to negotiate the relevant parameters of the LDP session,

The party with the larger transmission address initiates the establishment of a TCP connection as the active party

PPP package

IP encapsulation

TCP Encapsulation

UDP Encapsulation

Dual power supply design

Module hot-swappable design

Issu Design

Dual-engine design

True

False

If the data packet source lIP address is 1001.2, it can be forwarded with the DSCP field marked CS3

If the packet source IP address is 1001.1, it can be forwarded while the DSCP field is marked as CS3

If the packet source IP address is 1001.2, it cannot be forwarded

If the packet source IP address is 1001.2, it can be forwarded while the DSCP field remains unchanged