Cisco 300-410 Online Practice Questions and Exam Preparation

Cisco 300-410 Online Questions & Answers

• Question 901:

  Refer to the following table:

  

  Path1, Path2, and Path3 are the available routes between routers A and B. The bgp always-compare med command is executed for all three routes.

  What should be the value for the missing ASN (represented by a question mark in the table) so that Path3 becomes the best path between routers A and B based on their MED values?

  A. 10
  B. 20
  C. 30
  D. 40
  D. 40

  ---

  The missing autonomous system number (ASN) in the AS_PATH parameter of Path3 should be 40 so that Path3 becomes the best path from A to B. BGP selects the best path by first selecting the first valid path between two routers. If other paths are available between the two routers, BGP compares values of various attributes to select the best available path. In this case, Path 2 is the current best path between routers A and B. The values of various parameters (listed in the table) are compared with Path1

  and Path2.

  While comparing Path1 and Path2, the weight, LOCAL_PREF, local originate source command, length of AS_PATH, and origin type are same. Therefore, these parameters are not useful in determining the best path. However, the MED value of Path2 is lower than that of Path1. As a result, Path2 is selected as the best path because BGP prefers the route with the lesser MED value.

  BGP now compares the parameter values of Path 2 (the current best path) and Path3. The weight and LOCAL_PREF parameters are same for both routes. Path 2 and Path3 are both local routes originated by using the redistribute and the network commands, respectively. BGP prefers local routes learned by the network or redistribute commands over those that are learned by the aggregate-address command.

  The AS_PATH parameter specifies the list of AS numbers that comprise the route. The best path should have the shortest value for the AS_PATH parameter. In this case, both Path2 and Path3 consist of three AS numbers and are originated by an IGP. Therefore, the AS_PATH and the origin type parameters are not helpful in determining the best path.

  Finally, BGP compares the MED values of Path2 and Path3. The MED values are compared only when the first AS number in the AS_PATH is the same for both routes; that is, when both routes begin in the same AS. The first ASN in the AS_PATH parameter of Path2 is 40; therefore, the missing ASN for Path3 should be 40. This allows the comparison of MED values and the selection of Path3 as the best route as it has lower MED value.

  All the other options are incorrect because a value other than 40 disables the comparison of the MED values between Path2 and Path3. If the MED value is not considered, then BGP determines whether Path3 is an iBGP or eBGP router.

  BGP selects an iBGP route instead of an eBGP route.

  Objective:

  Layer 3 Technologies

  Sub-Objective:

  Explain BGP attributes and best-path selection

  References:

  Internetworking Technology Handbook > BGP > BGP attributes

• Question 902:

  Refer to the exhibit.

  

  An engineer configured BGP between routers R1 and R3. The BGP peers cannot establish neighbor adjacency to be able to exchange routes. Which configuration resolves this issue?

  A. R3 router bgp 6502 neighbor AB01:2011:7:100::1 ebgp-multihop 255
  B. R1 router bgp 6501 address-family ipv6 neighbor AB01:2011:7:100::3 activate
  C. R1 router bgp 6501 neighbor AB01:2011:7:100::3 ebgp-multihop 255
  D. R3 router bgp 6502 address-family ipv6 neighbor AB01:2011:7:100::1 activate
  D. R3 router bgp 6502 address-family ipv6 neighbor AB01:2011:7:100::1 activate

• Question 903:

  A Cisco router has just been configured for NTP and is synchronized with the configured NTP server. However, log messages still show an incorrect time. What else should be done to match the log messages time stamps with the NTP based time?

  A. Wait a bit longer for the synchronized time to get applied to new log messages.
  B. Configure the "service timestamps log datetime localtime" command in global mode.
  C. Configure the "service timestamps log datetime synchronize" command globally
  D. Configure the "service timestamps log ntp" command in global config mode.
  B. Configure the "service timestamps log datetime localtime" command in global mode.

• Question 904:

  Which failure detection mechanism is used for BFD?

  A. consistent rate
  B. Layer 2 protocol failure
  C. variable rate
  D. routing protocol failure
  A. consistent rate

  ---

  BFD provides a consistent failure detection method for network administrators. Because the network administrator can use BFD to detect forwarding path failures at a uniform rate https://www.cisco.com/en/US/docs/ios/12_4t/ip_route/configuration/guide/t_bfd.html

• Question 905:

  Examine the exhibit.

  

  The router labeled "B" has been configured by using the following configuration commands:

  RouterB(config)# router eigrp 100 RouterB(config-router)# network 10.0.0.0 RouterB(config-router)# distribute-list 10 in bri 0 RouterB(config)# access-list 10 deny 11.11.0.0 0.0.255.255 RouterB(config)# access-list 10 permit any

  Which statement best describes the effects of this configuration?

  A. Only network 11.11.0.0 will be advertised to routers A and C.
  B. Advertisements received by router A will include router D networks.
  C. Advertisements to router C will not include the router D and E networks.
  D. Traffic from network 11.11.0.0 hosts will be discarded because of ACL 10.
  B. Advertisements received by router A will include router D networks.

  ---

  The router will scan the access list specified by a distribute list. If a match to a permit statement is found, the route entry is permitted; if a match is found to a deny statement, the route is discarded. In this question, the permit statement in ACL 10 provides a permit match to all routes advertised from router D except for network 11.11.0.0.

  Distribute lists are used to filter inbound, outbound, or redistributed routing updates. Instead of using the passive-interface command, distribute lists enable you to selectively control which routes are processed.

  If a distribute list is associated with an interface, the routing update is compared to the access list that was specified in the distribute list. If a match is found to a permit statement, then the packet is forwarded. If a match is found to a deny statement, the packet is discarded. If no match is found, the implicit deny statement at the end of the access list will drop the packet. For example, if the access list in the above example were missing the line access-list 10 permit any, all updates would be denied, not just the

  one specified by the deny statement.

  If no distribute list is associated with the interface, the routing update packets are processed as normal.

  Distribute lists can reference multiple access lists if required to obtain the desired result. For example, examine the following configuration from a partial output of show run:

  router eigrp

  distribute-list 2 out ethernet 0

  distribute-list 1 out

  !

  access-list 1 permit 10.0.0.0 0.255.255.255

  access-list 2 permit 10.0.1.0 0.0.0.255

  By using two access lists and two distribute lists, you accomplish the following:

  Only routes matching 10.0.0.0/8 will be advertised out interfaces other than E0 Only routes matching 10.0.1.0/24 will be advertised out E0

  Network 11.11.0.0 will not be the only network advertised to routers A and C. In this question, the permit statement in ACL 10 provides a permit match to all routes advertised from router D except for network 11.11.0.0.

  The option advertisements to Router C will not include the router D and E networks is incorrect because although the 11.11.0.0/16 network will be denied, any other networks attached to either Router C or Router D will be permitted.

  Traffic from network 11.11.0.0 hosts will NOT be discarded because of ACL 10. If the access list were applied to the interface with the access-group command instead of the distribute-list command, this would be the case, but a distribute list blocks routing updates, not normal traffic.

  Objective:

  Layer 3 Technologies

  Sub-Objective:

  Configure and verify filtering with any protocol

  References:

  Cisco > Home > Support > Technology Support > IP > IP Routing > Design > Design Technotes > Filtering Routing Updates on Distance Vector IP Routing Protocols

• Question 906:

  What does the PE router convert the IPv4 prefix to within an MPLS VPN?

  A. 48-bit route combining the IP and PE router-id
  B. VPN IPv4 prefix combined with the 64-bit route distinguisher
  C. prefix that combines the ASN, PE router-id and IP prefix
  D. eBGP path association between the PE and CE sessions
  B. VPN IPv4 prefix combined with the 64-bit route distinguisher

  ---

  The IP prefix is a member of the IPv4 address family. After the PE device learns the IP prefix, the PE converts it into a VPN-IPv4 prefix by combining it with an 8-byte route distinguisher (RD). The generated prefix is a member of the VPN-IPv4 address family. It uniquely identifies the customer address, even if the customer site is using globally nonunique (unregistered private) IP addresses. The route distinguisher used to generate the VPN-IPv4 prefix is specified by a configuration command associated with the virtual routing and forwarding (VRF) instance on the PE device.

• Question 907:

  An automatic IPv4-compatible IPv6 tunnel exists between two IPv6 networks. The two IPv6 networks belong to different BGP autonomous systems (AS). The tunnel source has the IPv4 address 172.168.111.65/24 and the tunnel destination has the IPv4 address 172.168.222.80/24. Which of the following statements is TRUE about the tunnel source and tunnel destination IPv6 addresses? (Choose two.)

  A. the IPv6 address of the tunnel source is 172.168.111.65::
  B. the IPv6 address of the tunnel source is ::172.168.111.65
  C. the IPv6 address of the tunnel destination is 172.168.222.80::
  D. the IPv6 address of the tunnel destination is ::172.168.222.80
  B. the IPv6 address of the tunnel source is ::172.168.111.65
  D. the IPv6 address of the tunnel destination is ::172.168.222.80

  ---

  The IPv6 address of the tunnel source is ::172.168.111.65 and the IPv6 address of the tunnel destination is

  ::172.168.222.80. These two addresses are IPv4-compatible IPv6 addresses, which are addresses that contain the IPv4 addresses of the tunnel source and destination.

  In automatic IPv4-compatible IPv6 tunnel, the IPv4 addresses of the tunnel source and the tunnel destination are used to determine their IPv6 addresses. The IPv4 addresses of the tunnel source/destination are embedded into the least significant 32 bits of an all-zero unicast IPv6 address. The resultant IPv6 address has zeros in the most significant 96 bits and the IPv4 address of the tunnel source/destination in the remaining 32 bits.

  In this case, the source of an automatic IPv4-compatible IPv6 tunnel has the IPv6 address

  0:0:0:0:0:0:172.168.111.65, abbreviated as ::2.168.111.65. You can also convert this address into pure hexadecimal format, which would be ACA8:6F41.

  Any of the following three addresses could be used to identify the BGP neighbor at 172.168.11.65:

  0:0:0:0:0:0:172.168.111.65 ::172.168.111.65 ::ACA8:6F41

  Similarly, the tunnel destination has the IPv6 address 0:0:0:0:0:0:172.168.222.80 (abbreviated as ::172.168.222.80). The hexadecimal form of the IPv6 address of the tunnel destination is ::ACA8:DE50.

  Any of the following three addresses could be used to identify the BGP neighbor at 172.168.222.80:

  0:0:0:0:0:0:172.168.222.80 ::172.168.222.80 ::ACA8:DE50

  The other two options state incorrect IPv6 addresses of the tunnel source and the tunnel destination. Both options specify an IPv6 address that has the IPv4 address of the tunnel source/destination in the most significant 32 bits and zeros in the least significant 96 bits.

  Objective:

  Network Principles

  Sub-Objective:

  Recognize proposed changes to the network

  References:

  Home > Support > Technology Support > IP > IP Version 6 (IPv6) > Configure > Configuration Examples and Technotes > IPv6 Tunnel Through an IPv4 Network > Configure > Configurations (Automatic IPv4-Compatible Mode) Cisco IOS IPv6 Implementation Guide > Implementing Tunneling for IPv6 Cisco > Support > Technology Support > IP > IP Version 6 (IPv6) > Technology Information > Technology White Paper > IPv6 Deployment Strategies > Selecting a Deployment Strategy > Deploying IPv6 Over

  IPv4 Tunnels > Automatic IPv4-Compatible Tunnel

• Question 908:

  Refer to the exhibit.

  

  R2 can access content on the server successfully. A network engineer finds packet drops on PC1 for traffic destined to network 2.2.2.2/32. Which action resolves the issue?

  A. Redistribute the connected metric in EIGRP.
  B. Add the eigrp stub connected static command.
  C. Redistribute the static metric in EIGRP.
  D. Remove the eigrp stub connected command.
  C. Redistribute the static metric in EIGRP.

  ---

  need to redistribute static https://community.cisco.com/t5/routing/eigrp-eigrp-stub-connected-static-summary/td-p/2575321#:~:text=the%20command%20%22%20eigrp%20stub%20connected,redistribute%20static%20routes%20in%20eigrp.

• Question 909:

  Which command is NOT mandatory for inclusion in a plan to implement IP Service Level Agreements (SLAs) to monitor IP connections and traffic?

  A. ip sla
  B. ip sla schedule
  C. ip sla reset
  D. icmp-echo
  C. ip sla reset

  ---

  The ip sla reset command is not mandatory for an implementation plan to configure IP SLAs for monitoring IP connections and traffic. This command causes the IP SLA engine to either restart or shutdown. As a result, all IP SLAs operations are stopped, IP SLA configuration information is erased, and IP SLAs are restarted. The IP SLAs configuration information will need to be reloaded to the engine.

  The following commands are essential to the implementation plan:

  ip sla ip sla schedule icmp-echo The ip sla command allows you to configure IP SLAs operations. When you execute this command in the global configuration mode, it enables the IP SLA configuration mode. In the IP SLA configuration mode, you can configure different IP SLA operations. You can configure up to 2000 operations for a given IP SLA ID number.

  The icmp-echo command allows you to monitor IP connections and traffic on routers by creating an IP SLA ICMP Echo operation. This operation monitors end-to-end response times between routers.

  The ip sla schedule command allows you to schedule the IP SLA operation that has been configured. With this command, you can specify when the operation starts, how long the operation runs, and the how long the operation gathers information. For example, if you execute the ip sla schedule 40 start-time now life forever command, the IP SLA operation with the identification number 40 immediately starts running. This is because the now keyword is specified for the start- time parameter. The forever

  keyword with the life parameter indicates that the operation keeps collecting information indefinitely. Note that you cannot re-configure the IP SLA operation after you have executed the ip sla schedule command.

  The information gathered by an IP SLA operation is typically stored in RTTMON-MIB. A Management Information Base (MIB) is a database hosting information required for the management of routers or network devices. The RTTMON-MIB is a Cisco-defined MIB intended for Cisco IOS IP SLAs. RTTMON MIB acts as an interface between the Network Management System (NMS) applications and the Cisco IOS IP SLAs operations.

  Objective:

  Infrastructure Services

  Sub-Objective:

  Configure and verify IP SLA

  References:

  Cisco > Support > Technology Support > IP > IP Application Services > Technology Information > Technology White Paper > Cisco IOS IP Service Level Agreements User Guide Cisco IOS IP SLAs Command Reference > icmp-echo through probe-packet priority > ip sla Cisco IOS IP SLAs Command Reference > icmp-echo through probe-packet priority > ip sla schedule Cisco > Cisco IOS IP SLAs Command Reference > icmp-echo

• Question 910:

  Refer to the exhibit.

  

  Router R1 (head office) is not always preferred for all users to access hosting services R1 should be primary, and the DR site should only be used if router R1 or its uplink fails. Which configuration resolves the issue?

  

  A. Option A
  B. Option B
  C. Option C
  D. Option D
  A. Option A