Cisco CCNP Enterprise 300-410 Questions & Answers

• Question 571:

  Which of the following commands would reveal the K values configured on an EIGRP router?

  A. debug ip eigrp

  B. debug eigrp packet

  C. show ip eigrp traffic

  D. show ip protocols

  Correct Answer: D

  The show ip protocols command gives information about any dynamic routing protocol, including EIGRP. With respect to EIGRP, it will show the K values as a part of the output. A sample is shown below:

  Routing Protocol is "eigrp 77"

  Outgoing update filter list for all interfaces is not set

  Incoming update filter list for all interfaces is not set

  Default networks flagged in outgoing updates

  Default networks accepted from incoming updates

  EIGRP metric weight K1=1,K2=0,K3=1,K4=0,K5=0

  EIGRP maximum, hopcount 100

  The debug ip eigrp command displays real-time information about EIGRP packets that are received and sent. It does not contain K values. A single line of this command output is shown below:

  Router# debug ip eigrp

  IP-EIGRP: Processing incoming UPDATE packet

  IP-EIGRP: Ext 192.168.5.0 255.255.255.0 M 386560 - 256000 130560 SM 360960 - 256000 104960

  The debug eigrp packet command displays general debug information, but not K values. A sample of this command output is shown below:

  Router# debug eigrp packet

  EIGRP: Sending HELLO on Ethernet0/1

  AS 109, Flags 0x0, Seq 0, Ack 0

  EIGRP: Received UPDATE on Ethernet0/1 from 192.195.78.24,

  AS 109, Flags 0x1, Seq 1, Ack 0

  The show ip eigrp traffic command displays packets received, as well as statistics on hello packets, updates, queries, and acknowledgments, but not K values. Partial output of this command is shown below:

  Router# show ip eigrp traffic

  IP-EIGRP Traffic Statistics for process 151

  Hellos sent/received: 220/205

  Updates sent/received: 7/29

  Queries sent/received: 2/0

  Replies sent/received: 0/2

  Acks sent/received: 29/14

  Objective:

  Layer 3 Technologies

  Sub-Objective:

  Describe and optimize EIGRP metrics

  References:

  Cisco IOS Master Command List, Release 12.4T > sa ipsec through show ip route dhcp > show ip protocols

• Question 572:

  An EIGRP network is configured with default settings for all the routers, shown in the exhibit. Traffic is not routing correctly.

  

  What commands need to be run, and on which router should it be run?

  A. The ip summary-address eigrp 500 172.16.0.0.0 255.255.0.0 command should be run on Router D.

  B. The ip summary-address eigrp 500 172.16.3.0.0 255.255.255.0 command should be run on Router C.

  C. The no auto-summary command should be run on Routers A, B, C and F

  D. The auto-summary command should be run on Router D.

  Correct Answer: C

  The no auto-summary command should be run on Routers A, B, C and F. When discontinuous networks exist in the network, as in this one, the auto summarization feature will prevent proper routing. Auto summarization is enabled by default.

  Discontinuous networks are subnets of a classful parent network address not located in the same area of the network. Because Routers A, B, C and F will all advertise a 10.0.0.0/8 network Router D will not only think that the 10.0.0.0/8

  network is on two different directions it will be unable to discern the individual subnets connected to each, leading to connectivity issues. Executing the no auto-summary command on those three routers will allow them to advertise subnets,

  clearing up the routing confusion created by auto summarization.

  The ip summary-address eigrp 500 172.16.0.0.0 255.255.0.0 command should not be run on Router D. This will manually configure the same summarization that is already occurring automatically, and will not solve the issue.

  The auto-summary command should not be run on Router D. This function is already being performed automatically and is the source of the routing problem. It should be disabled instead.

  Objective:

  Layer 3 Technologies

  Sub-Objective:

  Configure and verify manual and autosummarization with any routing protocol

  References:

  Cisco > Support > Technology Support > IP > IP Routing > Technology Information > Technology Whitepaper > Enhanced Interior Gateway Routing Protocol > Document ID: 16406 > Summarization

• Question 573:

  You need to resolve a route-selection problem in a redistributed network by increasing the administrative distance to several networks for a protocol, other than EIGRP or BGP, so that these routes will not be used. You create access list 5 to identify the relevant networks, and access the routing protocol configuration prompt.

  Which command will set the administrative distance to these networks to 220 for the selected protocol?

  A. Router(config-router)# list 5 distance 220

  B. Router(config-router)# admin 220 access-list 5

  C. Router(config-router)# distance 220 0.0.0.0 255.255.255.255 5

  D. Router(config-router)# increase 0.0.0.0 255.255.255.255 admin 220 list 5

  Correct Answer: C

  The correct command is Router(config-router)# distance 220 0.0.0.0 255.255.255.255 5. This command instructs the router to change the AD for any networks specified in the access list 5 to 220.

  The correct syntax for the distance command is shown below:

  distance weight [address mask [ access-list-number | name]

  The weight parameter is the administrative distance (AD), which is a number from 10 to 255. Note: Distances 0 through 9 are reserved for system use.

  To change the administrative distance for an entire routing protocol, use the distance command, as shown below:

  Router(config)# router rip

  Router(config-router)# distance 125

  To change the AD for only selected networks, use an access list with the distance command as shown below:

  Router(config)#access-list 5 permit 10.0.0.0 255.0.0.0

  Router(config)#access-list 5 permit 11.0.0.0 255.0.0.0

  Router(config)#access-list 5 permit 12.0.0.0 255.0.0.0

  Router(config)#router rip

  Router(config-router)# distance 220 0.0.0.0 255.255.255.255 5

  The 0.0.0.0 255.255.255.255 portion included with the distance command could hold an address/mask combination for a single address, but it is more common to use an access list.

  Objective:

  Layer 3 Technologies

  Sub-Objective:

  Describe administrative distance

  References:

  Cisco > Cisco IOS IP Routing: Protocol-Independent Command Reference > distance (ip)

• Question 574:

  You are troubleshooting a PPPoE connection that is supposed to maintain a connection with the ISP, even if no interesting traffic exists. The configuration of the dialer interface is shown below:

  

  What command should you add to ensure the connection is maintained in the absence of interesting traffic?

  A. dialer -group

  B. dialer persistent

  C. dialer list

  D. dialer string

  Correct Answer: B

  The dialer persistent command is used to specify that the connection stays up even in the absence of interesting traffic. Interesting traffic is user-defined traffic that triggers a call to the remote end. Were it present in the configuration, the section would appear as follows:

  

  The dialer-group command is assigns the dialer interface to a dialer group. It is an optional setting, and does not appear in this configuration.

  The dialer-list command is used to specify an access list that defines interesting traffic. It is an optional setting, and would NOT be a part of a configuration that does not maintain the connection based on interesting traffic. If you use dialer

  persistent, then you don't need to use dialer-list. The dialer list defines interesting traffic, while dialer persist keep the connection up in the absence of interesting traffic.

  The dialer string command is used to define the number to call to make the connection. It is present in the configuration in the scenario, and specifies the number 713 555 0199.

  Objective:

  Layer 2 Technologies

  Sub-Objective:

  Configure and verify PPP

  References:

  Cisco Dial Configuration Guide, Release 15.0S > Part 5: Dial-on-Demand Routing Configuration > Configuring Peer-to-Peer DDR with Dialer Profiles Cisco Press > Articles > Cisco Network Technology > General Networking > End-to-End

  DSL Architectures

• Question 575:

  Which command shows only OSPF routes installed into the routing table?

  A. show ip route

  B. show ip ospf route

  C. show ip route ospf

  D. show ip ospf

  E. show ip ospf database

  Correct Answer: C

  The correct answer is show ip route ospf.

  The show ip route ospf command shows you all the OSPF learned routes in the routing table. An example of the command and its output are below with an explanation of some of the terminology.

  Router5# show ip route ospf

  O IA 10.0.0.0/8 [110/65] via 5.0.0.2, 00:00:20, Serial1/1/0 S 0.0.0.0/0 [110/1] via 5.0.0.2, 00:00:20, Serial1/1/0 O E2 172.16.0.0 [110/25] via 5.0.0.2, 00:00:30, Serial1/1/0

  -indicates that the route was learned from OSPF.

  IA - indicates that the route is an inter area route, meaning it was learned via summary type 3 link state advertisements (LSAs). S - indicates that a static default route has been configured. E2 - indicates that the route is an external router

  redistributed from another protocol. Via - indicates the next hop address to use and the local interface from which to send [110/65]- indicates the administrative distance with the first value and the cost in the second (AD/cost).

  The full legend of the possible route codes is below:

  Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF

  external type 2

  i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area

  * - candidate default, U - per-user static route, o - ODR

  P - periodic downloaded static route

  The commands below can be used to monitor and verify OSPF operation:

  show ip route - displays known routes and from which protocol the routes were discovered, but for all routing protocols, not just OSPF. show ip ospf - displays the number of times the SPF algorithm has run and the default Link State Update

  (LSU) interval, but not the OSPF routes. show ip ospf database - displays the router ID, the OSPF process ID, and the contents of the topological database but not the routing table.

  There is no show ip ospf route command.

  Objective:

  Layer 3 Technologies

  Sub-Objective:

  Configure and verify OSPF operations

  References:

  Cisco > Cisco IOS IP Routing: Protocol-Independent Command Reference > show ip route

• Question 576:

  Which of the following commands should you use to determine both the feasible successors and the non- feasible successors to a given destination network?

  A. show ip route eigrp

  B. show ip eigrp topology

  C. show ip eigrp topology all-links

  D. show ip eigrp topology zero-successors

  Correct Answer: C

  The show ip eigrp topology all-links command displays both feasible successors and non-feasible successors to a given destination network. This command displays the contents of the topology table and shows all the routes available for a given destination network.

  An example of partial output of the command is below:

  

  The 172.20.2.0/24 network has a feasible successor. This can be determined by looking at the values in the parenthesis next to each route. The second value after the / is the advertised distance from the successor. This value must be less

  than the value of the feasible distance for a route to be considered a feasible successor. There are two routes for 172.20.2.0/24. The first route listed, via 172.17.3.1, is the successor route. Its cost is 246983122, which matches the feasible

  distance (FD). The second route, via 172.17.1.1, has an advertised distance of 2443698 (the second value in the parentheses after the /). Because this value is less than the FD (2413698), it qualifies as a feasible successor.

  The 172.25.1.0/24 network does not have a feasible successor. The second route listed via 172.17.1.1 has an advertised distance of 2501649, which is greater than the value of the FD, (2416381). Therefore, it is not a feasible successor.

  You should not use the show ip route eigrp command. This command displays only the best metric routes (successors) to a given destination network. A route has the best metric if it has the least feasible distance, which refers to the sum of

  the metric from a given neighbor to a destination network and the metric to reach that neighbor.

  You should not use the show ip eigrp topology command without the all-links parameter. This command displays only the feasible successors to a given destination network.

  You should not use the show ip eigrp topology zero-successors command because this command lists those routes that do not have a valid successor.

  Objective:

  Layer 3 Technologies

  Sub-Objective:

  Configure and verify policy-based routing

  References:

  Cisco IOS IP Routing: EIGRP Command Reference > show ip eigrp topology

• Question 577:

  Which commands will prevent the local router from advertising the 139.10.0.0 network out of the Ethernet 0/0 interface, while allowing all other networks to be advertised?

  A. RouterA(config)router rip RouterA(config-router)# network 10.0.0.0 RouterA(config-router)# network 139.10.0.0 RouterA(config-router)# network 199.10.10.0 RouterA(config-router)# distribute-list 10 out e0/0 RouterA(config)# access-list 10 deny 139.10.0.0 0.0.255.255 RouterA(config)# access-list 10 permit any

  B. RouterA(config)router rip RouterA(config-router)# network 10.0.0.0 RouterA(config-router)# network 139.10.0.0 RouterA(config-router)# network 199.10.10.0 RouterA(config-router)# distribute-list 10 in e0/0 RouterA(config)# access-list 10 deny 139.10.0.0 0.0.255.255 RouterA(config)# access-list 10 permit any

  C. RouterA(config)# router rip RouterA(config-router)# network 10.0.0.0 RouterA(config-router)# network 139.10.0.0 RouterA(config-router)# network 199.10.10.0 RouterA(config-router)# access-group 10 out e0/0 RouterA(config)# access-list 10 deny 139.10.0.0 0.0.255.255 RouterA(config)# access-list 10 permit any

  D. RouterA(config)# router rip RouterA(config-router)# network 10.0.0.0 RouterA(config-router)# network 139.10.0.0 RouterA(config-router)# network 199.10.10.0 RouterA(config)# access-list 10 deny 139.10.0.0 0.0.255.255 RouterA(config)# access-list 10 permit any RouterA(config)# interface e0/0 RouterA(config-if)# access-group 10 out

  Correct Answer: A

  The following command set will prevent the local router from advertising the 139.10.0.0 network out of the Ethernet 0/0 interface, while allowing all other networks to be advertised:

  RouterA(config)# router rip RouterA(config-router)# network 10.0.0.0 RouterA(config-router)# network 139.10.0.0 RouterA(config-router)# network 199.10.10.0 RouterA(config-router)# distribute-list 10 out e0/0 RouterA(config)# access-list 10 deny 139.10.0.0 0.0.255.255 RouterA(config)# access-list 10 permit any

  The distribute-list command allows you to apply a basic access list to a routing process. Just like applying an access list to an interface, when you apply it to a routing process, the permit statements determine what networks may be advertised out the interface. The deny statements determine what networks are not allowed to be advertised out the interface. Instead of applying the access list to an interface, you use the distribute-list command in router configuration mode to apply it to the particular routing process. By specifying an interface and a direction (in or out) in the distribute-list command, you can indicate where the advertisements will be blocked and in what direction.

  Keep in mind that when applied this way, the access list does not affect what data traffic passes through the interface. It only affects what networks that the routing protocol will advertise. In the scenario here, RIP will not send advertisements for the 139.10.0.0 network out Ethernet 0/0, but traffic coming from or going to that network is still allowed through the interface in either direction unless there is an access list applied to the interface that will block it.

  Conversely, if you applied an access-list to the interface that blocked traffic to or from the 139.10.0.0 network, but permitted all other traffic, it would not stop the routing updates about the 139.10.0.0 from passing through.

  Note: The last command in the sequence, RouterA(config)#access-list 10 permit any, is VERY important. If that line is missing, any route not specified with an allow statement will be denied. For example, if you wanted to only allow one

  network to be advertised, you could configure an allow statement for that network and leave off the permit any parameter. It would block all advertisements with the exception of the one specified by the allow statement.

  The following command set is incorrect because the distribute list is applied inbound, which would prevent the reception of updates concerning the 139.10.0.0/16 but would not prevent them from being advertised:

  RouterA(config)# router rip

  RouterA(config-router)# network 10.0.0.0

  RouterA(config-router)# network 139.10.0.0

  RouterA(config-router)# network 199.10.10.0

  RouterA(config-router)# distribute-list 10 in e0/0

  RouterA(config)# access-list 10 deny 139.10.0.0 0.0.255.255

  RouterA(config)# access-list 10 permit any

  The following command set is incorrect because it applies an access list to the interface instead of a distribute list. The effect would be to block all traffic for that network, but allow routing updates:

  RouterA(config)# router rip

  RouterA(config-router)# network 10.0.0.0

  RouterA(config-router)# network 139.10.0.0

  RouterA(config-router)# network 199.10.10.0

  RouterA(config-router)# access-group 10 out e0/0

  RouterA(config)# access-list 10 deny 139.10.0.0 0.0.255.255

  RouterA(config)# access-list 10 permit any

  The following command set is incorrect because it also applies an access list instead of a distribute list, this time incoming instead of outgoing:

  RouterA(config)# router rip

  RouterA(config-router)# network 10.0.0.0

  RouterA(config-router)# network 139.10.0.0

  RouterA(config-router)# network 199.10.10.0

  RouterA(config)# access-list 10 deny 139.10.0.0 0.0.255.255

  RouterA(config)# access-list 10 permit any

  RouterA(config)# interface e0/0

  RouterA(config-if)# access-group 10 out

  Objective:

  Layer 3 Technologies

  Sub-Objective:

  Configure and verify filtering with any protocol

  References:

  Cisco > Cisco IOS IP Configuration Guide, Release 12.2 > Configuring IP Routing Protocol-Independent Features > Filtering Routing Information Cisco > Cisco IOS IP Routing: Protocol-Independent Command Reference > distribute-list out

  (IP)

• Question 578:

  The exhibit is a frame relay hub-and-spoke topology with router A as the hub.

  

  You want to use the OSPF routing protocol between all three locations. Which interface configuration commands are required on router A? (Choose three.)

  A. ip ospf network broadcast

  B. ip ospf network point-to-point

  C. ip ospf network point-to-multipoint

  D. frame-relay map 10.20.10.21 221

  E. frame-relay map 10.20.10.22 222

  F. frame-relay map ip 10.20.10.21 221 broadcast

  G. frame-relay map ip 10.20.10.22 222 broadcast

  Correct Answer: CFG

  In OSPF point-to-multipoint mode, the routers will automatically identify each neighbor. The election of a designated router (DR) and backup designated router (BDR) are not required. This RFC compliant mode of operation is commonly found

  in partial mesh topologies, such as hub-and-spoke designs. In the diagram shown in the scenario, router A is the hub.

  The frame relay serial interface has one DLCI to each spoke location. DLCI 221 is used by router A to communicate with router C and DLCI 222 is used to communicate with router B. On router A's serial interface, point-to-multipoint mode is

  enabled with the ip ospf network configuration command. The following is the syntax of the ip ospf network command:

  ip ospf network [{broadcast | nonbroadcast | point-to-multipoint | point-to-multipoint nonbroadcast}]

  The command parameters are as follows:

  broadcast - This mode enables the interface to emulate a LAN. This mode requires a full or partial mesh topology.

  nonbroadcast - This RFC 2328 compliant mode is also referred to as NBMA mode. The neighbors must be statically configured.

  point-to-multipoint - This RFC 2328 compliant mode is used in partial mesh topologies, such as hub-and- spoke. Routers use additional LSAs to discover neighboring routers instead of manually defining DRs and BDRs. The hub router floods

  link state updates (LSUs) by duplicating the update to be sent to each routers using the respective DLCI.

  point-to-multipoint nonbroadcast - This is a Cisco extension to the point-to-multipoint mode.

  This mode is useful when the frame relay virtual circuits do not support broadcast traffic. Neighbors are manually defined.

  There is no point-to-point parameter for the ip ospf command. Creating a point-to-point configuration differs in that the point-to-point parameter is executed as a parameter of the command that creates the subinterface that hosts the point-topoint connection as shown below:

  Router(config)# interface serial 0.1 point-to-point

  When configuring a serial interface without sub-interfaces, OSPF will check the encapsulation to determine the network type. HDLC and PPP default to point-to-point while Frame-Relay encapsulation defaults to nonbroadcast.

  The frame-relay map command identifies the mapping between the Layer 3 address (IP address) and the Layer 2 address (DLCI). The frame relay virtual circuits from the hub router are identified as supporting broadcast traffic by using the

  frame-relay map command with the broadcast keyword.

  Objective:

  Layer 2 Technologies

  Sub-Objective:

  Explain Frame Relay

  References:

  Cisco > Home > Support > Support Technology > Support > IP Routing > Configure > Configuration Examples and Technotes > Initial Configurations for OSPF over Frame Relay Subinterfaces Cisco > Cisco IOS Wide-Area Networking

  Command Reference > frame-relay lapf n201 through fr-atm connect dlci > frame-relay map

• Question 579:

  Which of the following is NOT true of the PPP Session Phase of PPPoE?

  A. PPP options are negotiated

  B. BNG sends a PPPoE Active Discovery Offer to the client

  C. Authentication is performed

  D. Once link setup is complete, data will be transferred across the PPP link within PPPoE headers

  Correct Answer: B

  The Broadband Network Gateway does not send a PPPoE Active Discovery Offer to the client during the PPP Session Phase. That action occurs during the Active Discovery Phase.

  During the PPP Session Phase, the following steps occur:

  PPP options are negotiated.

  Authentication is performed.

  Network Control Protocols (NCP) for any Layer 3 protocols that will traverse the link are started, and these Layer 3 packets will be transmitted within PPPoE headers.

  Objective:

  Layer 2 Technologies

  Sub-Objective:

  Configure and verify PPP

  References:

  Cisco Support Community > ASR9000 BNG debugging PPPoE sessions Cisco > Cisco Security Appliance Command Line Configuration Guide, Version 8.0 > Configuring the PPPoE Client > PPPoE Client Overview

• Question 580:

  After configuring a PPPoE client on and Ethernet interface, you discover the connection is not working. You execute the show run command to view the PPPoE configuration, part of which is shown in the following output:

  

  What command is missing?

  A. vpdn-group

  B. request dialin

  C. protocol pppoe

  D. vpdn enable

  Correct Answer: D

  The command vpdn enable is required to enable virtual private dialup networking. If this command has not been executed, the other commands will not take effect. While some commands are optional, the following tasks are required to set up the PPP over Ethernet client feature: Enable PPPoE in a VPDN Group Configure a PPPoE Client

  Configure the Dialer Interface

  The first step includes these three sub-tasks:

  1.

  Enable virtual private dialup networking using the vpdn enable command.

  2.

  Associate a VPDN group with a customer or VPDN profile using the vpdn-group name command.

  3.

  Create a request-dialin VPDN subgroup using the request-dialin command.

  4.

  Enable the VPDN subgroup to establish PPPoE sessions using the protocol pppoe command.

  In the output in the scenario, we can see that all tasks were taken care of in the first section except for enabling virtual private dialup networking. Had hat been done, the first section would correctly appear as:

  vpdn enable

  vpdn-group 1

  request-dialin

  protocol pppoe

  !

  The rest of the configuration is correct. The following section configures the PPPoE client and specifies the dialer interface to use for cloning:

  interface ethernet1/1

  pppoe-client dial-pool-number 1

  pppoe-client dial-pool-number 2

  The following sections configure two dialer interfaces. They specify that the IP addresses for the interfaces are obtained via PPP/IPCP (IP Control Protocol) address negotiation and that the dialing pools to use to connect to a specific

  destination subnetwork. Finally, they configure the interfaces to belong to a specific dialing group.

  !

  interface dialer 1

  ip address negotiated

  dialer pool 1

  dialer-group 1

  !

  interface dialer 2

  ip address negotiated

  dialer pool 2

  dialer-group 2

  Objective:

  Layer 2 Technologies

  Sub-Objective:

  Configure and verify PPP

  References:

  Cisco Press > Articles > Cisco Network Technology > General Networking > End-to-End DSL Architectures PPP over Ethernet Client