Cisco 300-410 Online Practice Questions and Exam Preparation

Cisco 300-410 Online Questions & Answers

• Question 131:

  Refer to the exhibit.

  

  A network engineer troubleshooting a packet drop problem for the host 172.16.100.5 notices that only one link is used and installed on the routing table, which saturates the bandwidth. Which action must the engineer take to resolve the high bandwidth utilization problem and share the traffic toward this host between the two available links?

  A. Disable the eigrp split horizon loop protection mechanism.
  B. Set the eigrp variance equal to 3 to install a second route with a metric not larger than 3 times of the best metric.
  C. Change the EIGRP delay metric to meet the feasibility condition.
  D. Set the eigrp variance equal to 4 to install a second route with a metric not larger than 4 times of the best metric.
  C. Change the EIGRP delay metric to meet the feasibility condition.

  ---

  From the output of the "show ip eigrp topology ..." command, we notice network 172.16.100.5/32 was learned via two routes:

  +

  From 10.4.1.5 with FD = 409600 and AD = 128256

  +

  From 10.3.1.6 with FD = 435200 and AD = 409600

  To use both paths (called unequal cost load balancing) with EIGRP, the second path must satisfy the feasibility condition. The feasibility condition states that, the Advertised Distance (AD) of a route must be lower than the feasible distance of the current successor route.

  In this case, the second path did not satisfy the feasible condition as its AD (409600) is equal to the FD of the best path -> Therefore we cannot configure load balancing with "variance" command.

• Question 132:

  You have configured BGP on both rtrA in AS 1 and rtrB in AS 2. There are two routes created using the network command between the two routers. One route traverses through AS 5 and AS 6 from rtrA to rtrB, while the other route traverses AS 7, AS 8, and AS 9 from rtrA to rtrB. Both routes use default values for the Weight and LOCAL_PREF attributes. Which of the following attributes determines the BEST route between rtrA and rtrB routers?

  A. Weight
  B. LOCAL_PREF
  C. Origin type
  D. AS_PATH
  D. AS_PATH

  ---

  The AS_PATH attribute is used to determine the best path between the two routes. To select the best path from rtrA to rtrB, BGP analyzes attributes that are set for the two available routes during the configuration of the network. The key BGP attributes and the order in which they are checked are as follows:

  1. Weight - highest weight is selected

  2. LOCAL_PREF - highest LOCAL_PREF is selected

  3. Locally originated routes - local routes are selected

  4. AS_PATH - shortest AS_PATH is selected

  5. Origin type - lowest origin type is selected

  6. Multi-exit Discriminator (MED) - lowest MED is selected

  The weight attribute is the first attribute to be checked while selecting the best BGP route. This attribute is relevant only to the local router on which it is set. The value of this attribute can be any number from 0 to 65535. The default values are 32768 for locally originated routes and 0 for other types of routes. Both routes in this case are originated locally and have the default weight values. Therefore, in this case, the weight attribute is not used to determine the best route.

  BGP then checks the value of the LOCAL_PREF attribute, which refers to local preference. Local preference is a value indicates the route that is preferred to exit the AS to reach a given network. Routes with higher local preference are selected by BGP. You can set the local preference for a route to any value; however, if you do not, the route uses the default value of 100. Because both routes have the default LOCAL_PREF value, this attribute is not used to determine the best route.

  Next BGP checks whether any of the routes are locally originated using the network, redistribute, or aggregate commands. As stated, both routes originated using the network command on the routers. Consequently, BGP analyzes the value of the AS_PATH attribute, which is a list of the AS numbers traversed by a particular route. The route with the shortest AS_PATH is selected as the best path. In this case, the route that consists of AS 5 and 6 is considered the best path because the AS_PATH value for

  this route is shorter than that for the route traversing AS 7, 8, and 9. The AS_PATH value for the route traversing AS 5 and 6 is [6 5 1], while the AS_PATH for the route traversing AS 7, 8, and 9 is [9 8 7 1].

  The other options are incorrect because the corresponding attributes are same for both the routes; hence, those attributes are not considered while BGP determines the best path.

  Objective:

  Layer 3 Technologies Sub-Objective: Explain BGP attributes and best-path selection

  References:

  Internetworking Technology Handbook > BGP > BGP attributes

• Question 133:

  Which of the following are valid fields in an MPLS header? (Choose four.)

  A. Label
  B. Sequence Number
  C. Experimental (Exp)
  D. Bottom of Stack (BoS)
  E. Time to Live (TTL)
  F. Checksum
  A. Label
  C. Experimental (Exp)
  D. Bottom of Stack (BoS)
  E. Time to Live (TTL)

• Question 134:

  Refer to the exhibit.

  

  Two routers are connected back to back via Gigabit Ethernet 0/0 interfaces. Which configuration provides VRF-Lite connectivity for two separate VRFs using the prefixes 10.1.1.0/24 for one VRF and 10.2.2.0/24 for the other VRF?

  A. ip vrf 1 rd 65001:1 ip vrf 2 rd 65001:2 ! int GigabitEthernet0/0 no shut ! int GigabitEthernet0/0.1 encapsulation dot1Q 1 ip vrf forwarding ip address 10.1.1.1 255.255.255.0 ! int GigabitEthernet0/0.2 encapsulation dot1Q 2 ip vrf forwarding ip address 10.2.2.1 255.255.255.0
  B. ip vrf 1 rd 65001:1 ip vrf 2 rd 65001:1 ! int GigabitEthernet0/0 no shut ! int GigabitEthernet0/0.1 encapsulation dot1Q 1 ip vrf forwarding 1 ip address 10.1.1.1 255.255.255.0 ! int GigabitEthernet0/0.2 encapsulation dot1Q 2 ip vrf forwarding 2 ip address 10.2.2.1 255.255.255.0
  C. ip vrf 1 ip vrf 2 int GigabitEthernet0/0 no shut ! int GigabitEthernet0/0.1 encapsulation dot1Q 1 ip vrf forwarding 1 ip address 10.1.1.1 255.255.255.0 ! int GigabitEthernet0/0.2 encapsulation dot1Q 2 ip vrf forwarding 2 ip address 10.2.2.1 255.255.255.0
  D. ip vrf 1 ip vrf 2 ! int GigabitEthernet0/0 no shut ! int GigabitEthernet0/0.1 encapsulation dot1Q 1 ip address 10.1.1.1 255.255.255.0 ip vrf forwarding 1 ! int GigabitEthernet0/0.2 encapsulation dot1Q 2 ip address 10.2.2.1 255.255.255.0 ip vrf forwarding 2
  C. ip vrf 1 ip vrf 2 int GigabitEthernet0/0 no shut ! int GigabitEthernet0/0.1 encapsulation dot1Q 1 ip vrf forwarding 1 ip address 10.1.1.1 255.255.255.0 ! int GigabitEthernet0/0.2 encapsulation dot1Q 2 ip vrf forwarding 2 ip address 10.2.2.1 255.255.255.0

  ---

  https://zartmann.dk/mpls-vpns-vs-vrf-lite/

• Question 135:

  Users report issues with reachability between areas as soon as an engineer configured summary routes between areas in a multiple area OSPF autonomous system. Which action resolves the issue?

  A. Configure the summary-address command on the ABR.
  B. Configure the area range command on the ASBR.
  C. Configure the summary-address command on the ASBR.
  D. Configure the area range command on the ABR.
  D. Configure the area range command on the ABR.

  ---

  For OSPF, we can only summary at the ABR with the command "area range" or at the ASBR with the command "summary-address" -> Therefore answer A and answer B are not correct. In this question, the most likely problem is that when doing summarization, the network mask is configured wrong and summarization doesn't work because of the misconfiguration. When configuring the area range command, make sure that the summarization mask is in the form of a prefix mask rather than a wildcard mask

  (that is, 255.255.255.0 instead of 0.0.0.255).

  Good reference: https://www.configrouter.com/troubleshooting-route-summarization-ospf-14082/

• Question 136:

  Refer to the exhibit.

  

  Which action resolves the issue?

  A. Configure host IP address in access-list 16.
  B. Configure SNMPv3 on the router.
  C. Configure SNMP authentication on the router.
  D. Configure a valid SNMP community string.
  D. Configure a valid SNMP community string.

  ---

  Looking at the configuration, it seems that there are two SNMP community strings configured, "public" and "private". However, the configuration does not specify which community string is being used by the host with IP address 10.1.1.1. The correct action to resolve this issue would be to configure a valid SNMP community string on the device from which the SNMP request is being made, and ensure that it matches the community string configured on the router.

• Question 137:

  Refer to the exhibit. The administrator noticed that the connection was flapping between the two ISPs instead of switching to ISP2 when the ISP1 failed. Which action resolves the issue?

  

  A. Include a valid source-interface keyword in the icmp-echo statement.
  B. Reference the track object 1 on the default route through ISP2 instead of ISP1.
  C. Modify the static routes to refer both to the next hop and the outgoing intertace.
  D. Modify the threshold to match the administrative distance of the ISP2 route.
  A. Include a valid source-interface keyword in the icmp-echo statement.

  ---

  https://www.cisco.com/c/en/us/support/docs/ip/ip-routing/200785-ISP-Failover-withdefault-routes-using-I.html

• Question 138:

  Refer to the exhibit. R1 is configured with IP SLA to check the availability of the server behind R6 but it kept failing.

  

  Which configuration resolves the issue?

  A. R6(config)#ip sla responder udp-echo ip address 10.10.10.1 port 5000
  B. R6(config)#ip access-list extended DDOS R6(config-ext-nacl)#5 permit icmp host 10.10.10.1 host 10.66.66.66
  C. R6(config)#ip sla responder
  D. R6(config)#ip access-list extended DDOS R6(config-ext-nacl)#5 permit icmp host 10.66.66.66 host 10.10.10.1
  B. R6(config)#ip access-list extended DDOS R6(config-ext-nacl)#5 permit icmp host 10.10.10.1 host 10.66.66.66

  ---

  In this IP SLA tracking, we don't need a IP SLA Responder so the command "ip sla responder" on R6 is not necessary.

  We also notice that the ACL is blocking ICMP packets on both interfaces E0/0 and E0/1 of R6 so we need to allow ICMP from source 10.10.10.1 to destination 10.66.66.66.

• Question 139:

  Refer to the exhibit.

  

  An administrator configures a router to stop using a particular default route if the DNS server 8.8.8.8 is not reachable through that route. However, this configuration did not work as desired and the default route still works even if the DNS server 8.8.8 8 is unreachable.

  Which two configuration changes resolve the issue? (Choose two.)

  A. Configure two static routes for the 8.8.8.8/32 destination to match the IP SLA probe for each ISP.
  B. Associate every IP SLA probe with the proper WAN address of the router.
  C. Reference the proper exit interfaces along with the next hops in both static default routes.
  D. Use a separate track object to reference the existing IP SLA 1 probe for every static route.
  E. Use a separate IP SLA probe and track object for every static route
  B. Associate every IP SLA probe with the proper WAN address of the router.
  E. Use a separate IP SLA probe and track object for every static route

• Question 140:

  An engineer is implementing a coordinated change with a server team. As part of the change, the engineer must configure interface GigabitEthernet2 in an existing VRF "RED", then move the interface to an existing VRF "BLUE" when the server team is ready. The engineer configured interface GigabitEthernet2 in VRF "RED".

  

  Which configuration completes the change?

  A. interface GigabitEthernet2 no ip address vrf forwarding BLUE
  B. interface GigabitEthernet2 no vrf forwarding RED vrf forwarding BLUE ip address 10.0.0.0 255.255.255.254
  C. interface GigabitEthernet2 no vrf forwarding RED vrf forwarding BLUE
  D. interface GigabitEthernet2 no ip address ip address 10.0.0.0 255.255.255.254 vrf forwarding BLUE
  B. interface GigabitEthernet2 no vrf forwarding RED vrf forwarding BLUE ip address 10.0.0.0 255.255.255.254