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
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
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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
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
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
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
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 vlanC. ports between switches should be configured in access mode so that vlans can span across the portsD. broadcast and multicast frames are retransmitted to ports that are configured on different vlan.
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
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
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、userB、hostC、cityD、destination
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、destinationB、resourceC、packetD、source
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.
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.
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.
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 vlanC、ports between switches should be configured in access mode so that vlans can span across the portsD、broadcast and multicast frames are retransmitted to ports that are configured on different vlan.
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.
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.
In JUNOS Software， which three packet elements can be inspected to determine if asession already exists？（）A、IP protocolB、IP time-to-liveC、source and destination IP addressD、source and destination MAC addressE、source and destination TCP/UDP port
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
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.
多选题Which two statements about an interface configured with the asr-group command are correct？ （）AThe FWSM supports up to 16 asymmetric routing groups.BIf a matching packet is not found， the packet is dropped.CAsymetric routing of return traffic is enabled.DIf a matching packet is found， the Layer 3 header is rewritten.EIf a matching packet is found， the Layer 3 header is rewritten and the packet is forwarded to thedefault gateway.
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
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
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（）AdestinationBresourceCpacketDsource
单选题If the PFE does not have a route to the destination address of a packet， which action will be taken？（）AThe PFE floods the packet out of all interfaces.BThe PFE drops the packet and sends a destination unreachable notification back to source device.CThe PFE forwards the packet to the routing engine for further processing.DThe PFE queues the packet and sends a request for a layer 3 lookup to the routing engine.