思科认证考试
Which of the following is not a characteristic of Cisco Express Forwarding？（）A、The adjacency table is populated from a router’s ARP cacheB、CEF does not require the first packet of a data flow to be process switchedC、CEF maintains the Forward Information B
题目
Which of the following is not a characteristic of Cisco Express Forwarding？（）
- A、The adjacency table is populated from a router’s ARP cache
- B、CEF does not require the first packet of a data flow to be process switched
- C、CEF maintains the Forward Information Base and the adjacency table
- D、CEF can be enabled with the interface command ip cef
- E、The FIB is populated from a router’s IP routing table
- F、On most router platforms CEF is enabled by default
相似问题和答案
第1题：
Cisco Express Forwarding (CEF) is mainly used to increase packet switching speed, reducing the overhead and delays introduced by other routing techniques, increasing overall performance.Which of the following concerning CEF is recommended by Cisco?（）
A. Use default Layer 4 hash in core.
B. Use default Layer 3 hash in distribution.
C. Use default Layer 4 hash in distribution.
D. Use default Layer 3 hash in core and Layer 3 + Layer 4 hash in distribution layer.
第2题：
Your boss， Miss ，is interested in CEF. What should you tell her？ （）
- A、The FIB lookup is based on the Layer 3 destination address prefix （shortest match）.
- B、The adjacent table is derived from the ARP table.
- C、The FIB table is derived from the IP routing table.
- D、When the adjacency table is full， a CEF TCAM table entry points to the Layer 3 engine to redirect the adjacency.
- E、CEF IP destination prefixes are stored in the TCAM table， from the least specific to the most specific entry.
- F、When the CEF TCAM table is full， packets are dropped.
正确答案:B,C,D
第3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 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
第4题：
Which two table types are CEF components？（）
- A、forwarding information base
- B、adjacency tables
- C、neighbor tables
- D、caching tables
- E、route tables
正确答案:A,B
第5题：
Cisco Express Forwarding has been enabled on router TK1. With CEF， prefixes that require exception processing can be cached with one of which four special adjacencies？ （）
- A、Kick
- B、Drop
- C、Forward
- D、Null
- E、Discard
- F、Glean
- G、Express
正确答案:B,D,E,F
第6题：
Which option correctly identifies the Cisco IOS switching methods in descending order from the fastest method to the slowest method？（）
- A、CEF， distributed CEF （dCEF）， fast switching， process switching
- B、distributed CEF （dCEF）， CEF， fast switching， process switching
- C、fast switching， process switching， distributed CEF （dCEF）， CEF
- D、process switching， fast switching， distributed CEF （dCEF）， CEF
- E、process switching， distributed CEF （dCEF）， CEF， fast switching
- F、process switching， CEF， distributed CEF （dCEF）， fast switching
正确答案:B
第7题：
Which of the following is not a characteristic of fast switching？（）
- A、Fast switching reducesa routers CPU utilization， compared to process switching
- B、All packets of a flow， except for the first packet， use the information in the fast cache
- C、It can be enabled with the interface command ip route-cache
- D、Fast switching uses a fast cache maintained in a router’s control plane
- E、The fast cache contains information about how traffic from different data flows should beforwarded
- F、Even though the fast switching is enabled， the first packet of a flow is still process switched
正确答案:D
第8题：
The router SIS-R has been configured in a CIS network. As a network administrator, you were required to enable MPLS on that router.Which of the following description is making sense on the basis of the output information?（）
A. CEF switching is only needed to forward labeled packets.
B. CEF switching is needed on both ingress and egress interfaces on which MPLS is enabled.
C. Interface-level CEF switching is needed only on egress interfaces that are sending IP packets on which the egress LSR performs the label imposition process.
D. Interface-level CEF switching is needed only on ingress interfaces that are receiving IP packets on which the ingress LSR performs the label imposition process.
第9题：
Which of the following data structures exist on a router for the OSPF routing protocol？（）
- A、OSPF topology table
- B、OSPF interface table
- C、OSPF routing information base
- D、OSPF link-state database
- E、OSPF adjacency table
- F、OSPF neighbor table
正确答案:B,C,D,F
第10题：
Which two statements describe the difference between JUNOS Software for securityplatforms and a traditional router？（）
- A、JUNOS Software for security platforms supports NAT and PAT； a traditional router does not support NAT or PAT.
- B、JUNOS Software for security platforms does not forward traffic by default； a traditional router forwards traffic by default.
- C、JUNOS Software for security platforms uses session-based forwarding； a traditional router uses packet-based forwarding.
- D、JUNOS Software for security platforms performs route lookup for every packet； a traditional router performs route lookup only for the first packet.
正确答案:B,C