400-101 exam questions


The article at Testaimer.com going over http://www.testaimer.com/400-101-test is very comprehensive.

Q341. DRAG DROP 

Drag and drop each IPv6 neighbor discovery message type on the left to the corresponding description on the right. 

Answer: 


Q342. Which three values can be used to tag external EIGRP routes? (Choose three.) 

A. The router ID of the router that redistributed the route 

B. The administrative distance of the external protocol 

C. The protocol ID of the external protocol 

D. The cost to reach the router that redistributed the route 

E. The metric from the external protocol F. The router ID of the router from which the external protocol route was learned 

Answer: A,C,E 

Explanation: 

EIGRP has the notion of internal and external routes. Internal routes are ones that have been originated within an EIGRP autonomous system (AS). Therefore, a directly attached network that is configured to run EIGRP is considered an internal route and is propagated with this information throughout the EIGRP AS. External routes are ones that have been learned by another routing protocol or reside in the routing table as static routes. These routes are tagged individually with the identity of their origination. External routes are tagged with the following information: 

The router ID of the EIGRP router that redistributed the route. 

The AS number where the destination resides. 

A configurable administrator tag. 

Protocol ID of the external protocol. 

The metric from the external protocol. 

Bit flags for default routing. 

Reference: http://www.cisco.com/c/en/us/support/docs/ip/enhanced-interior-gateway-routing-protocol-eigrp/13669-1.html#route_tagging 


Q343. When deploying redundant route reflectors in BGP, which attribute can you configure on the route reflector to allow routes to be identified as belonging to the same group? 

A. ROUTER_ID 

B. CLUSTER_ID 

C. ORIGINATOR_ID 

D. PEER_GROUP 

Answer:

Explanation: 

Together, a route reflector and its clients form a cluster. When a single route reflector is deployed in a cluster, the cluster is identified by the router ID of the route reflector. The bgp cluster-id command is used to assign a cluster ID to a route reflector when the cluster has one or more route reflectors. Multiple route reflectors are deployed in a cluster to increase redundancy and avoid a single point of failure. When multiple route reflectors are configured in a cluster, the same cluster ID is assigned to all route reflectors. This allows all route reflectors in the cluster to recognize updates from peers in the same cluster and reduces the number of updates that need to be stored in BGP routing tables. 

Reference: http://ieoc.com/forums/t/5326.aspx 


Q344. Which option is the default point of insertion for the BGP cost community? 

A. before best path calculation 

B. after best path calculation 

C. after the IGP metric comparison 

D. after the router ID comparison 

Answer:


Q345. As a best practice, when a router is configured as an EIGRP Stub, which routes should be received from its distribution neighbor? 

A. the default route 

B. static routes 

C. internal routes only 

D. internal and external routes 

Answer:

Explanation: 

Stub routing is commonly used in a hub and spoke network topology. In a hub and spoke network, one or more end (stub) networks are connected to a remote router (the spoke) that is connected to one or more distribution routers (the hub). The remote router is adjacent only to one or more distribution routers. The only route for IP traffic to follow into the remote router is through a distribution router. This type of configuration is commonly used in WAN topologies where the distribution router is directly connected to a WAN. The distribution router can be connected to many more remote routers. Often, the distribution router will be connected to 100 or more remote routers. In a hub and spoke topology, the remote router must forward all nonlocal traffic to a distribution router, so it becomes unnecessary for the remote router to hold a complete routing table. Generally, the distribution router need not send anything more than a default route to the remote router. 

Reference: http://www.cisco.com/c/en/us/td/docs/ios/12_0s/feature/guide/eigrpstb.html 


Q346. Which option describes a limitation of Embedded Packet Capture? 

A. It can capture data only on physical interfaces and subinterfaces. 

B. It can store only packet data. 

C. It can capture multicast packets only on ingress. 

D. It can capture multicast packets only on egress. 

Answer:

Explanation: 

Restrictions for Embedded Packet Capture 

. In Cisco IOS Release 12.2(33)SRE, EPC is supported only on 7200 platform. 

. EPC only captures multicast packets on ingress and does not capture the replicated packets on egress. 

. Currently, the capture file can only be exported off the device; for example, TFTP or FTP servers and local disk. 

Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/epc/configuration/15-mt/epc-15-mt-book/nm-packet-capture.html 


Q347. Which three statements are true about PPP CHAP authentication? (Choose three.) 

A. PPP encapsulation must be enabled globally. 

B. The LCP phase must be complete and in closed state. 

C. The hostname used by a router for CHAP authentication cannot be changed. 

D. PPP encapsulation must be enabled on the interface. 

E. The LCP phase must be complete and in open state. 

F. By default, the router uses its hostname to identify itself to the peer. 

Answer: D,E,F 

Explanation: 

Point-to-Point Protocol (PPP) authentication issues are one of the most common causes for dialup link failures. This document provides some troubleshooting procedures for PPP authentication issues. 

Prerequisites 

. Enable PPP encapsulation 

. The PPP authentication phase does not begin until the Link Control Protocol (LCP) phase is complete and is in the open state. If debug ppp negotiation does not indicate that LCP is open, troubleshoot this issue before proceeding. 

Note. By default, the router uses its hostname to identify itself to the peer. However, this CHAP username can be changed through the ppp chap hostname command. 

Reference: http://www.cisco.com/c/en/us/support/docs/wan/point-to-point-protocol-ppp/25647-understanding-ppp-chap.html 


Q348. Which CoS value is mapped to DSCP 48 by default? 

A. 6 

B. 7 

C. AF21 

D. AF44 

E. AF41 

F. 46 

Answer:


Q349. Refer to the exhibit. 

If EIGRP is configured between two routers as shown in this output, which statement about their EIGRP relationship is true? 

A. The routers will establish an EIGRP relationship successfully. 

B. The routers are using different authentication key-strings. 

C. The reliability metric is enabled. 

D. The delay metric is disabled. 

Answer:

Explanation: 

The 5 K values used in EIGRP are: 

K1 = Bandwidth modifier 

K2 = Load modifier 

K3 = Delay modifier 

K4 = Reliability modifier 

K5 = Additional Reliability modifier 

However, by default, only K1 and K3 are used (bandwidth and delay). In this output we see that K1, K3, and K4 (Reliability) are all set. 


Q350. Refer to the exhibit. 

Which statement is true? 

A. R2 is directly connected to the receiver for this group and is the winner of an assert mechanism. 

B. R2 is directly connected to the receiver for this group, and it forwards the traffic onto Ethernet3/0, but it is forwarding duplicate traffic onto Ethernet3/0. 

C. R2 has the A flag (Accept flag) set on Ethernet 3/0. This is fine, since the group is in BIDIR-PIM mode. 

D. R2 is directly connected to the receiver for this group and is the loser of an assert mechanism. 

E. The A flag is set until the SPT threshold is reached for this multicast group. 

Answer:

Explanation: 

show ip mroute Field Descriptions 

Field 

Description 

RPF neighbor or RPF nbr 

IP address of the upstream router to the source. Tunneling indicates that this router is sending data to the RP encapsulated in register packets. The hexadecimal number in parentheses indicates to which RP it is registering. Each bit indicates a different RP if multiple RPs per group are used. If an asterisk (*) appears after the IP address in this field, the RPF neighbor has been learned through an assert. 

Reference: http://www.cisco.com/c/en/us/td/docs/ios/12_2/ipmulti/command/reference/fiprmc_r/1rfmult 3.html