Which of the following advanced features does BGP EVPN support?
- A . ARP broadcast suppression
- B . VRRP over VXLAN
- C . Multi-live gateway
- D . VXLAN Qos
Which of the following statements about VXLAN messages is correct? (Multiple choice)
- A . The outer destination IP address is the IP address of the remote VTEP of the VXLAN tunnel.
- B . The source UDP port number is 4789
- C . Destination UDP port number is 4789
- D . VNI has 24 bits and is used to distinguish VLAN segments.
Which of the following types of packets is required to implement virtual machine migration in the BGP EVPN distributed gateway scenario?
- A . Type3
- B . Type5
- C . Type4
- D . Type2
- E . Type1
Which of the following statements about the BFD single-arm echo function are correct? (Multiple Choice)
- A . The BFD single-arm echo function must be configured with a local identifier and a remote identifier.
- B . The default destination IP address of the BFD single-arm echo function protocol packet is 224.0.0.184.
- C . BFD single-arm echo function is applicable to scenarios where one device supports BFD and the other device does not.
- D . After the BFD single-arm echo function is enabled, the destination IP and source IP of the BFD packets are the same.
The following statements about the VRRP protocol which are correct?
- A . Both VRRPv2 and VRRPv3 support authentication.
- B . VRRPv3 does not support authentication, while VRRPv2 supports authentication.
- C . VRRPv2 is only applicable to IPv4 networks, and VRRPv3 is only applicable to IPv6 networks.
- D . The owner of the Mater IP address has VRRP priority of 255, so the priority range that can be configured is 0-254.
HW users are transmitting a lot of files through TFTP.
What protocol does TFTP rely on for transmission?
- A . IcmP and UDP
- B . iP and TCP
- C . UDP
- D . NFS
- E . FTP
When deploying LLQ, you need to configure bandwidth parameters. What is the meaning of bandwidth parameters?
- A . Provide a built-in policer to limit the maximum available bandwidth of low latency queues during congestion
- B . This parameter should be as small as possible. It means that the bandwidth is always reserved, even if LLQ is used, this parameter will reduce the available bandwidth of the interface.
- C . It indicates that the reference CR is used to calculate the burst size of the built-in policer token bucket.
- D . This parameter is an option because LLQ always takes precedence over other queues
Assume that the port shaping rate is 100Mbps. The input bandwidth and PIR configured by IP of each service on the interface are as follows.
Then, after the first round of scheduling, what is the bandwidth allocated by the EF queue?
- A . 30M
- B . 15M
- C . 90M
- D . 25M
As shown in the figure, there are two IPv6 networks that can access the IPv4 network. At the same time, an IPSEC tunnel needs to be established between the two IPv6 networks for communication. Which of the following encapsulation modes can meet the requirements above? 
- A . ESP + tunnel mode
- B . None of the above options
- C . AH + transmission mode
- D . AH + tunnel mode
Which of the following does the digital certificate not contain?
- A . Public key information
- B . Digital envelope
- C . Digital signature
- D . Issuer
The LAND attack is performed by the attacker sending a source address and a destination address to the destination host are the destination host, the same SYN packet on source port and the destination port. When the receiver waits for the final ACK packet from the sender, the connection is always in a semi-connected state, resulting in waste of limited TCP resources at the receiving end.
- A . True
- B . False
The following statement about the security confederation SA in IPsec, which is wrong?
- A . The SA is uniquely identified by a triplet that includes the Security Parameter Index (SP), the source IP address and the security protocol number used (AH or ESP).
- B . Use display IPsec to view information about encryption algorithms, traffic, and other information used between another IPsec peer.
- C . IPsec only supports the use of symmetric encryption algorithms to encrypt data.
- D . There must be two-way SA between IPsec peers to establish an IPsec VPN connection.
Router HW1 and router HW2 are connected to network A and network B respectively. As shown below, if you want to establish an IPsec VPN between router HW1 and router HW2.
Which ACL does the router HW1 need to configure to enable LAN-to-LAN traffic to pass through the encrypted VPN tunnel?
- A . rule permit ip source 192.168.1.10 destination 192.168.1.2 0
- B . rule permit ip source 10.1.1.0 0.0.0.255 destination 192.168.1.2 0
- C . rule permit ip source 10.1.1.0 0.0.0.255 destination 10.1.2.0 0.0.0.255
- D . rule permit ip source 192.168.1.10 destination 10.1.2.0 0.0.0.255
- E . rule permit ip source 10.1.2.0 0.0.0.255 destination 10.1.1.0 0.0.0.255
Which of the following options is correct for the assertion mechanism?
- A . The size of the IP address will not be used as a condition for election during the election of the winner.
- B . In the assertion mechanism, winner is responsible for forwarding multicast data to the broadcast network segment.
- C . The assertion mechanism is used for the election of the DR.
- D . In the assertion mechanism, loser shut down the interface connected to the broadcast network.
If there are multiple receivers in a multicast group, the administrator enables IGMP-Snooping on the switch connecting the receiver. After the receiver receives the general query message from the querier, the receiver receives multiple receivers. How to respond?
- A . All recipients will respond to the Report message.
- B . Only when IGMPv1 is running, all receivers respond to the Report message.
- C . The first responder with a response timeout sends a Report message, and the other recipients do not send it.
- D . Only the IGMPV2 is running, and all receivers respond to the Report message.
If running PIM-SM on a multicast network, you need to construct a multicast forwarding tree between the multicast source and the receiver to enable the receiver to receive multicast data. Which of the following description about the constructed multicast forwarding tree is correct? (Multiple Choice)
- A . The RTP tree is built between the RP and the receiver.
- B . The RPT tree is built between the multicast source and the RP.
- C . The SPT tree is built between the RP and the receiver.
- D . The SPT tree is built between the multicast source and the RP.
The following description of the BSR mechanism, which is correct? (Multiple Choice)
- A . There can be multiple C-BSR in a PIM-SM domain, but only one BSR can be elected.
- B . The BSR collects C-RP information through the received C-RP data packets.
- C . The BSR advertises BSR information and C-RP information to all routers in the PIM-SM domain by flooding Bootstrap packets.
- D . One C-BSR can also collect C-RP information through received C-RP packets.
The following are the statements about LDP reliability, which one is wrong?
- A . LDP FRR can also be used to generate an LSP for the label mapping from the non-optimal next hop. And it can be as a backup of the primary LSP to establish the transfer entries.
- B . The association between the LDP and the IGP requires the IGP to suppress the advertisement of the route and ensure that the LDP path is consistent with the IGP path.
- C . The manually configured LDP FRR policy defaults to a 32-bit backup route that triggers LDP to establish a backup LSP.
- D . LDP GR Graceful Restart uses the feature that the MPLS forwarding plane is separated from the control plane. The device does not interrupt when the protocol is restarted or the active/standby switchover is performed.
The following is about the LDP protocol session establishment process, which is the correct description? (Multiple choice)
- A . After the TCP connection is successfully established, the active party sends an initialization message to negotiate the parameters related to the LDP session.
- B . The party with the larger transmission address acts as the active party and initiates the establishment of TCP connection.
- C . The Hello message discovered by the LDP neighbor uses TCP packets. The destination address is the multicast address 224.0.0.2.
- D . After both parties receive the Keepalive message from the peer, the LDP session is established successfully.
RD is used to distinguish the same IP address in different VPNs. How many bits does the RD contain?
- A . 64
- B . 32
- C . 16
- D . 128
The association between LDP and IGP refers to the suppression of the issuance of reachable routes through IGP. To ensure that the LDP and IGP linkages complete network convergence. Make the IGP and LDP keep the path consistent. Minimize the loss of traffic and improve the reliability of the entire network.
- A . True
- B . False
Regarding the processing mode of MPLS for TTL, which description is correct?
- A . In Pipe mode, when an IP packet passes through the MPLS network, the IP TTL is decremented by 1 to the MPLS TTL field on the ingress node.
- B . The TTL of the MPLS label has the same meaning as the TTL in the IP header, which can prevent the MPLS network from generating a routing loop
- C . Uniform simulation, when the IP packet passes through the MPLS network, the IP TTL of the ingress node is decremented by 1, and the MPLS TTL field is a fixed value.
- D . In MPLS VPN, if you want to hide the structure of the MPLS backbone network, you can use the uniform mode for Ingress packets for private network packets.
In an MPLS VPN network, different CE devices can exchange routing information with the same PE device using different routing protocols. The routing protocols used between different CE devices and the same device are independent of each other.
- A . True
- B . False
Which of the following technologies use tunneling technology to communicate between IPv6 addresses? (Multiple Choice)
- A . Dual Stack
- B . 6to4
- C . ISATAP
- D . NAT64
If the router only needs to forward IPv6 packets, there is no need to configure any IPv4 protocols and addresses on the router.
- A . Ture
- B . False
The following procedure for NDP to resolve the link layer address is correct or not.
- A . Ture
- B . False
BGP 4+ runs between the two routers. The neighbor relationship is normal. However, the BGP routing table of the local router does not have neighbor’s routing entry. What is the possible reason? (Multiple Choice)
- A . The routing entries of the peer BGP routing table are non-optimal.
- B . The next hop address of the BGP routing entry is unreachable.
- C . Peer ignore configured on the peer
- D . Active-route-advertise configured on the peer
Which of the following options may affect the establishment of IBGP neighbors? (Multiple Choice)
- A . Authentication is unsuccessful
- B . The BGP protocol version is inconsistent
- C . IBGP-Multi-hop is not configured
- D . IGP routing is unreachable
Which of the following tools cannot be directly referenced by the If-match clause in the Route-policy?
- A . Regular expression
- B . IP-prefix
- C . AS-path-filter
- D . Community-filt
Which of the following information can be included in a basic network layer packet? (Multiple choice)
- A . Data link layer header
- B . Upper layer data
- C . Network layer header
- D . Path record
- E . Network layer tail