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（请作答此空）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（ ）.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.routingB.forwardingC.transmissionD.management
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（请作答此空）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（ ）.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.routing
B.forwarding
C.transmission
D.management
B.forwarding
C.transmission
D.management
参考解析
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。
相关考题：
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 routers 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 routers 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
TCP functions at the Open Systems Interconnection(OSI)transport layer, or Layer 4. Its chief responsibility is to ensure reliable end-to-end connectivity. IP, located one layer （1）, at the OSI network layer, or Layer 3,communicates the addresses of each packet’s sender and receiver to the routers along the way .Routers and Layer 3 switches can read IP and other Layer 3 protocols. This information, combined with routing tables and other network intelligence, it takes to get across the room or around the world（2）TCP/IP.The routing process begins with an IP address that is（3）to the sending end station. End stations may be assigned permanent IP addresses or they may borrow them as needed from a Dynamic Host Configuration Protocol(DHCP)server or other service. If the sending end station determines that the destination address is not local, the packet goes to a first-hop router, typically one that is close and has been reassigned to the（4）. The router inspects the packet’s IP address and performs a route table lookup to see if the destination end station resides on the local(physically connected)network, typically called an IP subnet. An IP subnet usually is assigned to each of the router’s network interfaces. If the destination IP address is local, the router searches an internal store of IP addresses and local-device media access control(MAC)addresses. This store is known as the Address Resolution Protocol(ARP) cache. ARP is the universal tool for（5）IP addresses to MAC addresses. If the destination’s MAC address appears, the router installs that MAC address in the packet header(removing its own MAC address because that’s no longer needed)and sends the packet to the destination end station.（1）A. upB. downC. sidewardD. back-fence（2）A. viaB. throughC. byD. through out（3）A. specialB. especialC. uniqueD. particular（4）A. accepterB. senderC. routerD. server（5）A. searchingB. lookingC. locatingD. matching
Router VE1 has just received a packet and needs to route it. What two actions must this router take in order to route incoming packets? (Choose two)A. Inspect the routing table to select the best path to the destination network addresses.B. Validate sources of routing information.C. Inspect the ARP table to verify a legitimate source MAC address for each packet.D. Identify the destination network address of each packet.E. Verify the receipt of routed packets by the next hop router.F. Identify the source network address of each packet.
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
The following configuration line was added to router R1 Access－list 101 permit ip 10.25.30.0 0.0.0.255 any What is the effect of this access list configuration?() A. permit all packets matching the first three octets of the source address to all destinationsB. permit all packet matching the last octet of the destination address and accept all source addressesC. permit all packet matching the host bits in the source address to all destinationsD. permit all packet from the third subnet of the network address to all destinations
The following configuration line was added to router R1 Access－list 101 permit ip 10.25.30.00.0.0.255 any What is the effect of this access list configuration?() A.ermit all packet smatching the first three octets of the source address to all destinationsB.permit all packet matching the last octet of the destination address and accept all source addressesC.permit all packet matching the host bits in the source address to all destinationsD.permit all packet from the third subnet of the network address to all destinations
Traditional network layer packet forwarding relies on the information provided by network layer （） protocols, or static routing, to make an independent （本题）decision at each hop within the network. The forwarding （）is based solely on the destination （）IP address. All packets for the same destination follow the same path across the network if no other equal-cost paths exist. Whenever a router has two equal-cost （）toward a destination, the packets toward the destination might take one or both of them, resulting in some degree of load sharing.A.switchB.hopC.hostD.cunstomer
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. multicastB. unicastC. broadcastD. multiple unicast
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.reliabilityB.flexibilityC.stabilityD.capability
What is the purpose using the traceroute command?（）A、to map all the devices on a network.B、to display the current TCP/IP configuration values.C、to see how a device MAC address is mapped to its IP address.D、to see the path a packet will take when traveling to a specified destination.E、to display the MTU values for each router in a specified network path from source to a destination.
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
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 TTLB、Layer 3 TTLC、Layer 3 source addressD、Layer 3 destination address
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
The following configuration line was added to router R1 Access-list 101 permit ip 10.25.30.0 0.0.0.255 any What is the effect of this access list configuration?（）A、permit all packets matching the first three octets of the source address to all destinationsB、permit all packet matching the last octet of the destination address and accept all source addressesC、permit all packet matching the host bits in the source address to all destinationsD、permit all packet from the third subnet of the network address to all destinations
给了两段documentation里的描述，问这个时候发哪种类型的ICMP包。 The interface on which the packet comes into the router is the same interface on which the packet gets routed out. The subnet or network of the source IP address is on the same subnet or network of the next-hop IP address of the routed packet.
If the router R1 has a packet with a destination address 192.168.1.255, what describes the operation of the network（）。A、R1 will forward the packet out all interfaces.B、R1 will drop this packet because this it is not a valid IP address.C、As R1 forwards the frame containing this packet, Sw-A will add 192.168.1.255 to its MAC table.D、R1 will encapsulate the packet in a frame with a destination MAC address of FF-FF-FF-FF-FF-FFE、As R1 forwards the frame containing this packet, Sw-A will forward it to the device assigned the IP address of 192.168.1.255.
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.
When an SRX series device receives an ESP packet, what happens?（）A、If the destination address of the outer IP header of the ESP packet matches the IP address of the ingress interface, it willB、If the destination IP address in the outer IP header of ESP does not match the IP address of the ingress interface, it willC、If the destination address of the outer IP header of the ESP packet matches the IP address of the ingress interface, based packet.D、If the destination address of the outer IP header of the ESP packet matches the IP address of the ingress interface, based of inner header, it will decrypt the packet.
单选题What is the purpose using the traceroute command?（）Ato map all the devices on a network.Bto display the current TCP/IP configuration values.Cto see how a device MAC address is mapped to its IP address.Dto see the path a packet will take when traveling to a specified destination.Eto display the MTU values for each router in a specified network path from source to a destination.
单选题The following configuration line was added to router R1 Access-list 101 permit ip 10.25.30.00.0.0.255 any What is the effect of this access list configuration?（）Aermit all packet smatching the first three octets of the source address to all destinationsBpermit all packet matching the last octet of the destination address and accept all source addressesCpermit all packet matching the host bits in the source address to all destinationsDpermit all packet from the third subnet of the network address to all destinations
多选题If an edge Label Switch Router （LSR） is properly configured，which three combinations are possible？（）AA received IP packet is forwarded based on the IP destination address and the packet is sent as an IP packet.BAn IP destination exists in the IP forwarding table. A received labeled packet is dropped because the label is not found in the LFIB table.CThere is an MPLS label-switched path toward the destination. A received IP packet is dropped because the destination is not found in the IP forwarding table.DA received IP packet is forwarded based on the IP destination address and the packet is sent as a labeled packet.EA received labeled IP packet is forwarded based upon both the label and the IP address.FA received labeled packet is forwarded based on the label. After the label is swapped，the newly labeled packet is sent.
单选题The following configuration line was added to router R1 Access-list 101 permit ip 10.25.30.00.0.0.255 any What is the effect of this access list configuration？（）Aermit all packets matching the first three octets of the source address to all destinationsBpermit all packet matching the last octet of the destination address and accept all source addressesCpermit all packet matching the host bits in the source address to all destinationsDpermit all packet from the third subnet of the network address to all destinations
单选题When an SRX series device receives an ESP packet, what happens?（）AIf the destination address of the outer IP header of the ESP packet matches the IP address of the ingress interface, it willBIf the destination IP address in the outer IP header of ESP does not match the IP address of the ingress interface, it willCIf the destination address of the outer IP header of the ESP packet matches the IP address of the ingress interface, based packet.DIf the destination address of the outer IP header of the ESP packet matches the IP address of the ingress interface, based of inner header, it will decrypt the packet.
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?（）AThe destination is a host on another subnet, so the router will not forward the packet.BThe destination is a host on the same subnet, so the router will forward the packet.CThe destination is a broadcast address, so the router will not forward the packet.DThe destination is a network address, so the router will forward the packet.
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? （）ALayer 2 TTLBLayer 3 TTLCLayer 3 source addressDLayer 3 transport protocolELayer 3 destination address
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? （）ALayer 2 TTLBLayer 3 TTLCLayer 3 source addressDLayer 3 transport protocolELayer 3 destination address
问答题给了两段documentation里的描述，问这个时候发哪种类型的ICMP包。 The interface on which the packet comes into the router is the same interface on which the packet gets routed out. The subnet or network of the source IP address is on the same subnet or network of the next-hop IP address of the routed packet.
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?（）ALayer 2 TTLBLayer 3 TTLCLayer 3 source addressDLayer 3 destination address