A router receives a packet from a neighbor with an MPLS shim header value of 0.What does the router do with this packet?（）A、It performs a label pop operation and an IP lookup.B、It performs a label swap operation and an IP lookup.C、It sends an error messag

题目

A router receives a packet from a neighbor with an MPLS shim header value of 0.What does the router do with this packet?（）

  • A、It performs a label pop operation and an IP lookup.
  • B、It performs a label swap operation and an IP lookup.
  • C、It sends an error message toward the egress router.
  • D、It sends an error message toward the ingress router.
相似考题

1.阅读下面的短文，回答问题 [When an IP packet arrives at a router, generally the router looks at the destination address of the packet, and forwards the packet to one of its network interfaces. The forwarding decision is usually done by looking up the destination address from another data structure called a forwarding table. The forwarding table is created by the router using the routing table and possible routing policies existing in the router. The router then creates a table where it lists which networks are accessible through which of the router’s network interfaces. An IP router looks at every IP packet individually and does the forwarding decision on a packet-by-packet basis. If something changes in the router’s routing table, a packet can take a different route from a preceding packet even if it has the same destination.] From the paragraph above，we can see that the router （ ） a forwarding table according to the routing table and possible routing policies existing in the router. When an IP packet arrives at a router, the （ ） part of packet is normally checked by the router. An IP router checks every IP Packet individually and makes the forwarding decision based on （ ）.A．is generating B．generate C．is generated D．generates A．forwarding table B．network interfaces C．routing policies D．destination address A．the destination address and network interfaces B．forwarding table and network interfaces C．the destination address and forward table D．routing policies and routing table

2.An internet is a combination of networks connected by (71) .When a datagram goes from a source to a (72) ，it will probably pass many (73) until it reaches the router attached to the destination network．A router receives a (74) from a network and passes it to another network．A router is usually attached to several networks．When it receives a packet，to which network should it pass the packet? The decision is based on optimization： Which of the available (75) is the optimum pathway?A．modemsB．routersC．switchesD．computers

3.A router receives a packet from a neighbor with an MPLS shim header value of 0.What does the router do with this packet?()A. It performs a label pop operation and an IP lookup.B. It performs a label swap operation and an IP lookup.C. It sends an error message toward the egress router.D. It sends an error message toward the ingress router.

4.● An internet is a combination of networks connected by （71） . When a datagram goes from a source to a （72） , it will probably pass many （73） until it reaches the router attached to the destination network. A router receives a （74） from a network and passes it to another network. A router is usually attached to several networks. When it receives a packet, to which network should it pass the packet? The decision is based on optimization: Which of the available （75） is the optimum pathway?（71）A. modemsB. routersC. switchesD. computers（72）A. userB. hostC. cityD. destination（73）A. destinationsB. routersC. packetsD. computers（74）A. destinationB. resourceC. packetD. source（75）A. pathwaysB. routersC. diagramsD. calls

参考答案和解析
正确答案:A
更多“A router receives a packet from ”相关问题

  • 第1题：

    When does the E－series router start monitoring DHCP traffic using the DHCP External function?()

    A. When the discovery packet enters the router from the DHCP client.

    B. Only when the offer packet enters the router from the DHCP server.

    C. When the acknowledge packet enters the router from the DHCP server.

    D. Only when the discovery packet leaves the router going to the DHCP server.


    参考答案：D

  • 第2题：

    Refer to the exhibit. What does the (*) represent in the output?()

    A.Packet is destined for a local interface to the router.

    B.Packet was translated, but no response was received from the distant device.

    C.Packet was not translated, because no additional ports are available.

    D.Packet was translated and fast switched to the destination.


    参考答案：D

  • 第3题：

    What is the best description of serialization delay？ （）

    • A、the time it takes for a Layer 3 switch or a router to switch a packet from an inbound interface to the queue of the outbound interface
    • B、the time it takes for a propagate from source to destination
    • C、the time it takes to place a frame on the physical medium for transport
    • D、the time a packet resides in the outbound queue of a router

    正确答案:C

  • 第4题：

    Which four statements about the Carrier Supporting Carrier （CSC） feature are true？ （）

    • A、MPLS is required between the PE and CE routers that connect the backbone carrier to the customer carrier.
    • B、The backbone carrier must enable the PE router to check that the packets it receives from the CErouter contain only the labels that the PE router advertised to the CE router.
    • C、Every packet that crosses the backbone carrier must be encapsulated so that the packet includes MPLS labels
    • D、AII PE routers that link the backbone carrier to the customer carrier must run Route Target Rewrite.
    • E、Arouting protocol is required between the PE and CE routers that connect the backbone carrierto thecustomer carrier. The routing protocol enables the customer carrier to exchange IGP routing information with the backbone carrier.

    正确答案:A,B,C,E

  • 第5题：

    The router receives a login request from a PPP over ATM client and examines the domain map for the client's domain. The router finds no entries currently configured within the domain map. What does the router do with the login request?（）

    • A、The router rejects it.
    • B、The router tunnels it via L2TP.
    • C、The router authenticates it locally.
    • D、The default virtual router authenticates it.

    正确答案:D

  • 第6题：

    Which message type is constructed and sent from an MSDP router to its MSDP peers when it  receives a PIM register message （knowing that the MSDP router is also configured as an RP for  the PIM domain）？（）

    • A、Source-Active Message
    • B、PIM Join
    • C、PIM Hello
    • D、MSDP Register

    正确答案:A

  • 第7题：

    A router receives a packet on interface 172.16.45.66/26. The source IP of the packet is 172.16.45.127/26 and the destination is 172.16.46.191/26.How will the router handle the packet?（）

    • A、The destination is a host on another subnet, so the router will not forward the packet.
    • B、The destination is a host on the same subnet, so the router will forward the packet.
    • C、The destination is a broadcast address, so the router will not forward the packet.
    • D、The destination is a network address, so the router will forward the packet.

    正确答案:C

  • 第8题：

    问答题
    What field in IP packet is prevent the packet from a route to router forever？

    正确答案： TTL （time to live）.
    解析： 暂无解析

  • 第9题：

    单选题
    A router receives an IPv6 packet which is 2000 bytes in length. The MTU of the outgoing interface is 1500 bytes. What action will the router take？（）
    A

    forwards the packet

    B

    fragments the packet

    C

    drops the packet silently

    D

    drops the packet and sends an ICMP message


    正确答案： C
    解析： 暂无解析

  • 第10题：

    单选题
    When does the E-series router start monitoring DHCP traffic using the DHCP External function?（）
    A

    When the discovery packet enters the router from the DHCP client.

    B

    Only when the offer packet enters the router from the DHCP server.

    C

    When the acknowledge packet enters the router from the DHCP server.

    D

    Only when the discovery packet leaves the router going to the DHCP server.


    正确答案： D
    解析： 暂无解析

  • 第11题：

    单选题
    What best describes processing delay？（）
    A

    the time required from receipt of the incoming frame， until the frame/packet has been queued for transmission

    B

    the time taken for a single packet to traverse the physical medium from one end to the other

    C

    the time taken to place a frame on the physical medium for transport

    D

    the time spent for a packet to reside in the output queue of a router


    正确答案： B
    解析： 暂无解析

  • 第12题：

    单选题
    A router receives a packet from a neighbor with an MPLS shim header value of 0.What does the router do with this packet?（）
    A

    It performs a label pop operation and an IP lookup.

    B

    It performs a label swap operation and an IP lookup.

    C

    It sends an error message toward the egress router.

    D

    It sends an error message toward the ingress router.


    正确答案： B
    解析： 暂无解析

  • 第13题：

    Refer to the exhibit. What will Router1 do when it receives the data frame shown?()

    A.Router1 will strip off the source MAC address and replace it with the MAC address 0000.0c36.6965.

    B.Router1 will strip off the source IP address and replace it with the IP address 192.168.40.1.

    C.Router1 will strip off the destination MAC address and replace it with the MAC address 0000.0c07.4320.

    D. Router1 will strip off the destination IP address and replace it with the IP address of 192.168.40.1.

    E.Router1 will forward the data packet out interface FastEthernet0/1.

    F.Router1 will forward the data packet out interface FastEthernet0/2.


    参考答案：A, C, F

  • 第14题：

    Anytime a host or a router has an IP datagram to send to another host or router, it has the（　）address of the receiver. This address is obtained from the DNS if the sender is the host or it is found in a routing table if the sender is a router. But the IP data gram must be（　） in a frame to be able to pass through the physical network. This means that the sender needs the （　）address of the receiver. The host or the router sends an ARP query packet. The packet includes the physical and IP addresses of the sender and the IP address of the receiver. Because the sender does not know the physical address of the receiver, the query is（　） over the network.Every host or router on the network receives and processes the ARP query packet, but only the intended recipient recognizes its IP address and sends back an ARP response packet.The response packet contains the recipient's IP and physical addresses. The packet is（请作答此空） directly to the inquirer by using the physical address received in the query packet.

    A. multicast
    B. unicast
    C. broadcast
    D. multiple unicast

    答案：B
    解析：
    任何时候主机或路由器要发送 IP 数据报发送给另一主机或路由器时，都需要知道接收方的逻辑地址。发送主机从 DNS 获得该地址，发送路由器则在路由表中找到该地址。但 IP 数据报必须封装在帧中才能通过物理网络。这意味着发送者需要知道接收者的物理地址。主机或路由器需发送 ARP 查询报文，该报文分组包含发送者的物理地址和 IP 地址及接收者的 IP 地址。这是因为送者不知道接收者的物理地址，所以需在全网广播报文。网络上的每个主机或路由器都能接收并处理该 ARP 查询报文，但只有预期的接收者识别其 IP 地址并响应该 ARP 报文。响应报文包含接收者的 IP 地址和物理地址。包含了接收者物理地址的响应报文分组通过单播的方式直接发送给发送者。

  • 第15题：

    Which of the following statements about authentication responses and conditions is true? （）(Choosetwo.)

    • A、When a router receives a failure response, it stops querying authentication methods.
    • B、When a router receives an error response, it stops querying authentication methods.
    • C、If the router receives a failure response from an authentication method, it queries the next method.
    • D、The router does not differentiate between failure and error responses; the authentication process is always interrupted.
    • E、If it receives no response from the authentication method, a router will determine the error condition On its own; the router also has the option to proceed to the next method in a list if configured accordingly.

    正确答案:A,E

  • 第16题：

    What best describes processing delay？（）

    • A、the time required from receipt of the incoming frame， until the frame/packet has been queued for transmission
    • B、the time taken for a single packet to traverse the physical medium from one end to the other
    • C、the time taken to place a frame on the physical medium for transport
    • D、the time spent for a packet to reside in the output queue of a router

    正确答案:A

  • 第17题：

    Which two statements are true about TCP communication?（）

    • A、The receiver acknowledges the final packet in each communications stream.
    • B、The receiver adds sequencing numbers to the packets received.
    • C、The sender adds sequencing numbers to the packets it sends.
    • D、The receiver acknowledges each packet it receives from the sending device.

    正确答案:A,C

  • 第18题：

    Which of the following statements about authentication responses and conditions is true?（）(Choose two.)

    • A、When a router receives a failure response, it stops querying authentication methods.
    • B、When a router receives an error response, it stops querying authentication methods.
    • C、If the router receives a failure response from an authentication method, it queries the next method.
    • D、The router does not differentiate between failure and error responses; the authentication process is always interrupted.
    • E、If it receives no response from the authentication method, a router will determine the error condition on its own; the router also has the option to proceed to the next method in a list if configured accordingly.

    正确答案:A,E

  • 第19题：

    What field in IP packet is prevent the packet from a route to router forever？


    正确答案:TTL （time to live）.

  • 第20题：

    单选题
    A router receives a packet on interface 172.16.45.66/26. The source IP of the packet is 172.16.45.127/26 and the destination is 172.16.46.191/26.How will the router handle the packet?（）
    A

    The destination is a host on another subnet, so the router will not forward the packet.

    B

    The destination is a host on the same subnet, so the router will forward the packet.

    C

    The destination is a broadcast address, so the router will not forward the packet.

    D

    The destination is a network address, so the router will forward the packet.


    正确答案： A
    解析： 暂无解析

  • 第21题：

    单选题
    An internet is a combination of networks connected by (1). When a datagram goes from a source to a (2), it will probably pass many (3) until it reaches the router attached to the destination network. A router receives a (4) from a network and passes it to another network. A router is usually attached to several networks. When it receives a packet, to which network should it pass the packet? The decision is based on optimization: Which of the available (5) is the optimum pathway? 空白（4）处应选择（）
    A

    destination

    B

    resource

    C

    packet

    D

    source


    正确答案： B
    解析： 互联网是由不同的网络通过路由器互联起来的。当数据包从源地发往目的地时，在到达目的地网络之前它可能经过多个路由器。路由器从一个网络接收到数据包之后就转发到另外一个网络。然而，一个路由器往往与几个网络连接，当路由器接收到一个数据时，它应该将数据包传向哪个网络呢？这将基于路径最优化决策。

  • 第22题：

    单选题
    What is the best description of serialization delay？ （）
    A

    the time it takes for a Layer 3 switch or a router to switch a packet from an inbound interface to the queue of the outbound interface

    B

    the time it takes for a propagate from source to destination

    C

    the time it takes to place a frame on the physical medium for transport

    D

    the time a packet resides in the outbound queue of a router


    正确答案： C
    解析： 暂无解析

  • 第23题：

    单选题
    A router receives an IPv6 packet which is 2000 bytes in length. The MTU of the outgoing interface is 1500 bytes. Which action will the router take?（）
    A

    Forward the packet.

    B

    Fragment the packet.

    C

    Drop the packet silently.

    D

    Drop the packet and send an ICMPv6 message.


    正确答案： A
    解析： 暂无解析

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