Cisco 300-410 Online Practice Questions and Exam Preparation

Cisco 300-410 Online Questions & Answers

• Question 71:

  Which two reasons would cause an LSP to break between two PE routers? (Choose two.)

  A. lost LDP adjacency
  B. matching labels
  C. prefix mismatch
  D. IGP hello adjacency
  E. MPLS not enabled
  A. lost LDP adjacency
  E. MPLS not enabled

• Question 72:

  Refer to the exhibit.

  

  Which statement about R1 is true?

  A. OSPF redistributes RIP routes only if they have a tag of one.
  B. RIP learned routes are distributed to OSPF with a tag value of one.
  C. R1 adds one to the metric for RIP learned routes before redistributing to OSPF.
  D. RIP routes are redistributed to OSPF without any changes.
  B. RIP learned routes are distributed to OSPF with a tag value of one.

• Question 73:

  You are the network administrator for a large software organization. You designed the LAN in the organization's main building for connecting the internal LAN to a WAN as shown below:

  

  You have configured EIGRP with the variance parameter set to 3 on all the routers to enable unequal load balancing from the 172.16.1.0 network to the WAN. The delay configured on each of the routers is shown in the LAN diagram, and the K values are set as follows:

  K1 = 0 K2 = 0 K3 = 1 K4 = 0 K5 = 0

  Which of the following paths are entered into the routing tables as a result of the unequal load balancing configured on the routers? (Choose all that apply.)

  A. RA-RB-RD-RH-RK
  B. RA-RB-RE-RI-RK
  C. RA-RC-RF-RI-RK
  D. RA-RC-RG-RJ-RK
  B. RA-RB-RE-RI-RK

  ---

  The only path is entered in the routing table as a result of the unequal load balancing configured on the routers:

  RA-RB-RE-RI-RK

  In EIGRP networks, bandwidth and delay are the default factors for calculating the metric/cost for a given route. Additional factors such as load and reliability can be considered in the computation of the EIGRP metric, as given in the following formula:

  Metric = [K1 * bandwidth + (K2 * bandwidth) / (256 - load) + K3 * delay] * [K5 / (reliability + K4)]

  In this case, only the K3 value has a non-zero value. This implies that only delay is taken into consideration to calculate the metric of the shortest path from 172.16.1.0 network to the WAN. The path with the lowest metric, which is delay in this scenario, is the shortest path, and is therefore entered automatically in the routing table. The total delay and the corresponding metric for the three best paths are given as follows:

  

  In the given table, the path RA-RB-RE-RI-RK has the lowest metric of 14080. This is the shortest path, so it would be entered in the routing table even if variance were not enabled. In this scenario variance is set to 3, which enables unequal load balancing among those paths that have a metric less than three times the least metric for the given route. Three times the least metric in this scenario is 42240 (14080 x 3). This implies that paths between the 172.16.1.0 network and the WAN having a metric less

  than 42240 participate in the load balancing. On metric values alone, those paths would appear in the routing tables. However, to be eligible to be a feasible successor the reported distance of the path must be less than the feasible distance (current best path). None of the paths, with the exception of RA-RB-RE-RI-RK meet that requirement. The path RA-RB-RD-RH-RK is not entered in the routing table as a result of the unequal load balancing. The scaled EIGRP delay for this path is 43520 (170 x 256),

  which is more than three times the least metric available from the 172.16.1.0 network to the WAN (42240). In addition, the reported distance for this path is more than the feasible distance. Therefore, the path RA-RB-RD-RH-RK is not used for balancing the load from the 172.16.1.0 network to the WAN and does not appear in the routing tables.

  Objective:

  Layer 3 Technologies

  Sub-Objective:

  Configure and verify EIGRP load balancing

  References:

  Cisco > Support > Technology Support > IP > IP Routing > Design > Design Technotes > How Does Unequal Cost Path Load Balancing (Variance) Work in IGRP and EIGRP? > Document ID: 13677 Cisco > Support > Technology Support > IP > IP Routing > Design > Design Technotes > How Does Load Balancing Work? > Document ID: 5212

  Cisco > Support > Technology Support > IP > IP Routing > Technology Information > Technology Whitepaper > Enhanced Interior Gateway Routing Protocol > Document ID: 16406 > Feasible Distance, Reported Distance, and Feasible Successor

• Question 74:

  What are two MPLS label characteristics? (Choose two.)

  A. The label edge router swaps labels on the received packets.
  B. Labels are imposed in packets after the Layer 3 header.
  C. LDP uses TCP for reliable delivery of information.
  D. An MPLS label is a short identifier that identifies a forwarding equivalence class.
  E. A maximum of two labels can be imposed on an MPLS packet.
  C. LDP uses TCP for reliable delivery of information.
  D. An MPLS label is a short identifier that identifies a forwarding equivalence class.

• Question 75:

  You have a DMVPN hub with the following configuration applied: What problem could occur if the bandwidth 1000 command were missing from the tunnel interface?

  

  A. the tunnel interface will intermittently flap up and down
  B. split horizon will prevent routing updates from traversing from spoke to spoke
  C. congestion will develop in the tunnel interface
  D. the IPsec association will fail
  A. the tunnel interface will intermittently flap up and down

  ---

  In the absence of a bandwidth command on the tunnel interface, the default bandwidth on a tunnel interface is 9 Kbps. EIGRP will use 50% of that (4.5K), which is too low. This will cause problems with the maintenance of EIGRP neighbor relationships. From time to time this will cause the tunnel to flap up and then down as the relationships go up and down. When you execute the bandwidth command it has no real effect on the bandwidth of the link but it will allow EIGRP to use 50% of 10k or 5k for its

  purposes, leaving 4k for data. This will have little impact on the data while maintaining the neighbor relationships.

  The bandwidth command will have no effect on split horizon. There will be no problems with split horizon, even though the output shows that it has been disabled on the tunnel interface with the no ip split-horizon eigrp 1 command.

  The bandwidth command will not cause congestion on the link. It will only lower the bandwidth available to data from 4.5K to 4K.

  The bandwidth command will not cause the IPsec association to fail. There is sufficient bandwidth for this process.

  Objective:

  VPN Technologies

  Sub-Objective:

  Describe DMVPN (single hub)

  References:

  Understanding Cisco Dynamic Multipoint VPN - DMVPN, mGRE, NHRP

• Question 76:

  Refer to the exhibit A company builds WAN infrastructure between the head office and POPs using DMVPN hub-and-spoke topology to provide end-to-end communication All POPs must maintain point-to-point connectivity with the head office Which configuration meets the requirement at routers R12 and R13?

  

  

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

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• Question 77:

  When the log keyword is added to an access list statement, CPU utilization increases. What is the source of the increased CPU utilization? (Choose all that apply.)

  A. the process switching of packets that match the ACE
  B. the incrementing of the match counter every 60 seconds
  C. the generation and transmission of log messages
  D. the CEF switching of packets that match the ACE
  A. the process switching of packets that match the ACE
  C. the generation and transmission of log messages

  ---

  The source of the increased CPU utilization will have two sources. First is the process switching of each packet that matches the ACE, which is a slower switching method than CEF switching. The second is the generation and transmission of the log messages. Both effects can be mitigated by adjusting the logging interval and the message interval.

  The CPU utilization does NOT increase from the incrementing of the match counter every 60 seconds. The match counter increments every 5 minutes by default.

  The CPU utilization does NOT increase from the CEF switching of packets that match the ACE. Those packets will be process switched, which is a much slower process than CEF switching.

  Objective:

  Infrastructure Security

  Sub-Objective:

  Configure and verify router security features

  References:

  Understanding Access Control List Logging

  Cisco > Cisco IOS Security Command Commands D to L > ip access-list log-update Cisco > Cisco IOS Broadband Access Aggregation and DSL Command Reference > logging rate-limit

• Question 78:

  In an MPLS network, which of the following describes the role of the Provider (P) router?

  A. To connect to customer edge (CE) devices
  B. To connect to PE routers and act as transit routers
  C. To impose MPLS labels
  D. To filter VPN routes in the core
  B. To connect to PE routers and act as transit routers

• Question 79:

  Which Layer 3 VPN attribute installs customer routes in the VRF?

  A. RD
  B. RT
  C. extended-community
  D. MPLS label
  B. RT

• Question 80:

  Refer to the exhibit.

  

  The primary link between R1 and R2 went down, but R3 is still advertising the 192.168.200.0/24 network to R1 and the 192.168.100.0/24 network to R2, which creates a loop. Which action resolves the issue?

  A. Configure the eigrp stub command under the EIGRP process on R2.
  B. Configure the summary-address 192.168.0.0 255.255.0.0 100 command on R3.
  C. Configure the eigrp stub command under the EIGRP process on R3.
  D. Configure the eigrp stub leak-map command under the EIGRP process on R1.
  C. Configure the eigrp stub command under the EIGRP process on R3.