When an IP packet is Layer 3－switched from a source in one VLAN to a destination in another VLAN,which field in a packet will be rewritten? ()A. Layer 2 TTLB. Layer 3 TTLC. Layer 3 source addressD. Layer 3 transport protocolE. Layer 3 destination address

题目
When an IP packet is Layer 3－switched from a source in one VLAN to a destination in another VLAN,which field in a packet will be rewritten? ()

A. Layer 2 TTL

B. Layer 3 TTL

C. Layer 3 source address

D. Layer 3 transport protocol

E. Layer 3 destination address

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.In JUNOS software with enhanced services, which three packet elements are inspected to determineif a session already exists? ()(Choose three.)A. IP protocolB. IP time-to-liveC. source and destination IP addressD. source and destination MAC addressE. source and destination TCP/UDP port

3.When an IP packet is Layer 3－switched from a source in one VLAN to a destination in anotherVLAN, which field in a packet will be rewritten? ()A. Layer 2 TTLB. Layer 3 TTLC. Layer 3 source addressD. Layer 3 transport protocolE. Layer 3 destination address

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?A．modemsB．routersC．switchesD．computers

参考答案和解析
参考答案：B
更多“When an IP packet is Layer 3－switched from a source in one VLAN to a destination in another VLAN,which field in a packet will be rewritten? () ”相关问题

  • 第1题：

    Which statement about vlan operation on cisco catalyst switches is true?()

    A. when a packet is received from an 802.1Q trunk,the vlan id can be determined from the source MAC address table.

    B. unkown unicast frames are retransmitted only to the ports that belong to the same vlan

    C. ports between switches should be configured in access mode so that vlans can span across the ports

    D. broadcast and multicast frames are retransmitted to ports that are configured on different vlan.


    参考答案：B

  • 第2题：

    When an IP packet is Layer 3-switched from a source in one VLAN to a destination in anotherVLAN, which field in a packet will be rewritten? （）

    • A、Layer 2 TTL
    • B、Layer 3 TTL
    • C、Layer 3 source address
    • D、Layer 3 transport protocol
    • E、Layer 3 destination address

    正确答案:B

  • 第3题：

    When an IP packet is Layer 3-switched from a source in one VLAN to a destination in another VLAN,which field in a packet will be rewritten? （）

    • A、Layer 2 TTL
    • B、Layer 3 TTL
    • C、Layer 3 source address
    • D、Layer 3 transport protocol
    • E、Layer 3 destination address

    正确答案:B

  • 第4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:C

  • 第5题：

    Which two statements are correct when you use the reject parameter as the next-hop value for a static route?（）

    • A、The packet is dropped and the packet's source is marked with the no-readvertise parameter.
    • B、The system sends the packet back to the source.
    • C、The packet is dropped from the network.
    • D、The system sends an ICMP message back to the source of the packet.

    正确答案:C,D

  • 第6题：

    Which statement about vlan operation on cisco catalyst switches is true?（）

    • A、when a packet is received from an 802.1Q trunk,the vlan id can be determined from the source MAC address table.
    • B、unkown unicast frames are retransmitted only to the ports that belong to the same vlan
    • C、ports between switches should be configured in access mode so that vlans can span across the ports
    • D、broadcast and multicast frames are retransmitted to ports that are configured on different vlan.

    正确答案:B

  • 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：

    In JUNOS Software， which three packet elements can be inspected to determine if asession already exists？（）

    • A、IP protocol
    • B、IP time-to-live
    • C、source and destination IP address
    • D、source and destination MAC address
    • E、source and destination TCP/UDP port

    正确答案:A,C,E

  • 第9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10题：

    单选题
    When an IP packet is Layer 3-switched from a source in one VLAN to a destination in another VLAN,which field in a packet will be rewritten? （）
    A

    Layer 2 TTL

    B

    Layer 3 TTL

    C

    Layer 3 source address

    D

    Layer 3 transport protocol

    E

    Layer 3 destination address


    正确答案： E
    解析： 暂无解析

  • 第11题：

    单选题
    Assuming that an IP packet is sent from a source address in VLAN1 to a destination address in VLAN2 through a layer-3 switch, which part of the packet will be changed?（）
    A

    Layer 2 TTL

    B

    Layer 3 TTL

    C

    Layer 3 source address

    D

    Layer 3 destination address


    正确答案： D
    解析： 暂无解析

  • 第12题：

    单选题
    If the PFE does not have a route to the destination address of a packet， which action will be taken？（）
    A

    The PFE floods the packet out of all interfaces.

    B

    The PFE drops the packet and sends a destination unreachable notification back to source device.

    C

    The PFE forwards the packet to the routing engine for further processing.

    D

    The PFE queues the packet and sends a request for a layer 3 lookup to the routing engine.


    正确答案： A
    解析： 暂无解析

  • 第13题：

    Traditional IP packet forwarding analyzes the（ ）IP address contained in the network layer header of each packet as the packet travels from its source to its final destination.A router analyzes the destination IP address independently at each hop in the network.Dynamic（ ）protocols or static configuration builds the database needed to analyze the destination IP address（the routing table）.The process of implementing traditional IP routing also is called hop-by-hop destination-based（ ）routing.Although successful，and obviously widely deployed，certain restrictions，which have been realized for some time，exist for this method of packet forwarding that diminish is（请作答此空）.New techniques are therefore required to address and expand the functionality of an IP-based network infrastructure.This first chapter concentrates on identifying these restrictions and presents a new archiecture，known as multiprotocol（ ）switching，that provides solutions some of these restrictions.

    A.reliability
    B.flexibility
    C.stability
    D.capability

    答案：B
    解析：
    传统的IP数据包转发分析目的IP地址,该地址包含在每个从源到最终目的地的网络层数据包的头部。一个路由器的分析目的IP地址，该地址独立在网络中的每跳。动态路由协议或静态配置构建数据库，该数据数据库需要分析目的IP地址（路由表）。实施传统的IP路由的过程也叫作基于目的地的逐条单播路由。虽然成功而且明显得广泛部署,并实现了一段时间，但是必然有某些限制,这种数据包转发方法的存在是减少了灵活性。新技术是因此需要地址和扩展一个基于ip的网络基础设施的功能。第一章集中在识别一种新的架构的限制条件和反馈,该架构众所周知是多协议标签交换,它为其中的一些限制条件提供解决方案。

  • 第14题：

    Assuming that an IP packet is sent from a source address in VLAN1 to a destination address in VLAN2 through a layer-3 switch, which part of the packet will be changed?（）

    • A、Layer 2 TTL
    • B、Layer 3 TTL
    • C、Layer 3 source address
    • D、Layer 3 destination address

    正确答案:B

  • 第15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（2）处应选择（）

    • A、user
    • B、host
    • C、city
    • D、destination

    正确答案:D

  • 第16题：

    If the PFE does not have a route to the destination address of a packet， which action will be taken？（）

    • A、The PFE floods the packet out of all interfaces.
    • B、The PFE drops the packet and sends a destination unreachable notification back to source device.
    • C、The PFE forwards the packet to the routing engine for further processing.
    • D、The PFE queues the packet and sends a request for a layer 3 lookup to the routing engine.

    正确答案:B

  • 第17题：

    Which two statements are true when source/destination filters are enabled? （）(Choose two.)

    • A、Excluded traffic is not accelerated.
    • B、Excluded traffic is only compressed.
    • C、Source/destination filter applies to all traffic sent from LAN to WAN.
    • D、Source/destination filters work in packet interception mode using RIPv2.

    正确答案:A,C

  • 第18题：

    Which two statements about an interface configured with the asr-group command are correct?（）

    • A、The FWSM supports up to 16 asymmetric routing groups.
    • B、If a matching packet is not found, the packet is dropped.
    • C、Asymetric routing of return traffic is enabled.
    • D、If a matching packet is found, the Layer 3 header is rewritten.
    • E、If a matching packet is found, the Layer 3 header is rewritten and the packet is forwarded to the default gateway.

    正确答案:B,C

  • 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：

    In JUNOS software with enhanced services, which three packet elements are inspected to determineif a session already exists? （）(Choose three.)

    • A、IP protocol
    • B、IP time-to-live
    • C、source and destination IP address
    • D、source and destination MAC address
    • E、source and destination TCP/UDP port

    正确答案:A,C,E

  • 第21题：

    多选题
    Which two statements about an interface configured with the asr-group command are correct？ （）
    A

    The FWSM supports up to 16 asymmetric routing groups.

    B

    If a matching packet is not found， the packet is dropped.

    C

    Asymetric routing of return traffic is enabled.

    D

    If a matching packet is found， the Layer 3 header is rewritten.

    E

    If a matching packet is found， the Layer 3 header is rewritten and the packet is forwarded to thedefault gateway.


    正确答案： B,C
    解析： 暂无解析

  • 第22题：

    单选题
    When an IP packet is Layer 3-switched from a source in one VLAN to a destination in anotherVLAN, which field in a packet will be rewritten? （）
    A

    Layer 2 TTL

    B

    Layer 3 TTL

    C

    Layer 3 source address

    D

    Layer 3 transport protocol

    E

    Layer 3 destination address


    正确答案： A
    解析： 暂无解析

  • 第23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。

相关内容