Q191. If two OSPF type 3 prefixes have the same metric, and are within the same process, which prefix(es) are installed into the routing table?
A. The route whose originator has the lower router ID.
B. Both routes are installed.
C. The route whose originator has the higher router ID.
D. The first route that is learned.
Answer: B
Explanation:
OSPF allows multiple equal-cost paths to the same destination. Since all link-state information is flooded and used in the SPF calculation, multiple equal cost paths can be computed and used for routing, and each route will be installed in the routing table.
Q192. Which three statements about DMVPN are true? (Choose three.)
A. It facilitates zero-touch configuration for addition of new spokes.
B. It supports dynamically addressed spokes using DHCP.
C. It features automatic IPsec triggering for building an IPsec tunnel.
D. It requires uses of IPsec to build the DMVPN cloud.
E. Spokes can build tunnels to other spokes and exchange traffic directly.
F. It supports server load balancing on the spokes.
Answer: A,C,E
Q193. Refer to the exhibit.
Which statement is true?
A. The command ip multicast rpf multitopology is missing from the configuration.
B. Multitopology routing for multicast has been enabled for IS-IS.
C. This output is invalid.
D. The command mpls traffic-eng multicast-intact is configured on this router.
Answer: B
Explanation:
The following is sample output from the show ip rpf command in a Multi-Topology Routing (MTR) routing environment. In Cisco IOS releases that support MTR, the “RPF topology” field was introduced to indicate which RIB topology is being used for the RPF lookup. For the “RPF topology” field in this example, the first topology listed (ipv4 multicast base) indicates where the nexthop of the RPF lookup is being conducted and the second topology listed (ipv4 unicast data) indicates where the route originated from.
Router# show ip rpf 10.30.30.32
RPF information for ? (10.30.30.32)
RPF interfacE. Ethernet1/0
RPF neighbor: ? (10.1.1.32)
RPF route/mask: 10.30.30.32/32
RPF typE. unicast (ospf 100)
Doing distance-preferred lookups across tables
RPF topology: ipv4 multicast base, originated from ipv4 unicast data
The table below describes the fields shown in the displays.
Table 15 show ip rpf Field Descriptions
Field
Description
RPF information for
Hostname and source address for which RPF information is displayed.
RPF interface
For the given source, the interface from which the router expects to receive packets.
RPF neighbor
For the given source, the neighbor from which the router expects to receive packets.
RPF route/mask
Route number and mask that matched against this source.
RPF type
Routing table from which this route was obtained, either unicast, MBGP, DVMRP, or static mroutes.
RPF recursion count
The number of times the route is recursively resolved.
Doing distance-preferred
Whether RPF was determined based on distance or length of mask.
Using Group Based VRF Select, RPF VRF.
The RPF lookup was based on the group address and the VRF where the RPF lookup is being performed.
Metric preference
The preference value used for selecting the unicast routing metric to the RP announced by the designated forwarder (DF).
Metric
Unicast routing metric to the RP announced by the DF.
RPF topology
RIB topology being used for the RPF lookup, and, if originated from a different RIB topology, which RIB topology the route originated from.
Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipmulti/command/imc-xe-3se-5700-cr-book/imc-xe-3se-3850-cr-book_chapter_010.html
Q194. Which statement describes what it means if a router has an OSPF priority set to 0?
A. A router with the OSPF priority set to 0 is one that can participate in the election of a DR. It has the highest priority.
B. A router with the OSPF priority set to 0 is one that cannot participate in the election of a DR, but it can become a BDR
C. A router with the OSPF priority set to 0 is one that cannot participate in the election of a DR. It can become neither a DR nor a BDR.
D. A router with the OSPF priority set to 0 is one that cannot participate in the election of a BDR, but it can become a DR
Answer: C
Q195. Which two BGP attributes are optional, non-transitive attributes? (Choose two.)
A. AS path
B. local preference
C. MED
D. weight
E. cluster list
Answer: C,E
Q196. Refer to the exhibit.
Which two are causes of output queue drops on FastEthernet0/0? (Choose two.)
A. an oversubscribed input service policy on FastEthernet0/0
B. a duplex mismatch on FastEthernet0/0
C. a bad cable connected to FastEthernet0/0
D. an oversubscribed output service policy on FastEthernet0/0
E. The router trying to send more than 100 Mb/s out of FastEthernet0/0
Answer: D,E
Explanation:
Output drops are caused by a congested interface. For example, the traffic rate on the outgoing interface cannot accept all packets that should be sent out, or a service policy is applied that is oversubscribed. The ultimate solution to resolve the problem is to increase the line speed. However, there are ways to prevent, decrease, or control output drops when you do not want to increase the line speed. You can prevent output drops only if output drops are a consequence of short bursts of data. If output drops are caused by a constant high-rate flow, you cannot prevent the drops. However, you can control them.
Reference: http://www.cisco.com/c/en/us/support/docs/routers/10000-series-routers/6343-queue-drops.html
Q197. Refer to the exhibit.
All switches have default bridge priorities, and originate BPDUs with MAC addresses as indicated. The numbers shown are STP link metrics. Which two ports are forwarding traffic after STP converges? (Choose two.)
A. The port connecting switch SWD with switch SWE
B. The port connecting switch SWG with switch SWF
C. The port connecting switch SWC with switch SWE
D. The port connecting switch SWB with switch SWC
Answer: C,D
Explanation:
Here, we know SWB to SWC are forwarding because we already identified the blocking port. So for the last correct answer let’s consider what must be done to prevent a switch loop between SWC/SWD/SWE. SWE to SWD will be blocked because SWC has a lower MAC address so it wins the forwarding port. And to look at it further, you could try to further understand what would happen with ports on SWG. Would the ports on SWG try to go through SWE or SWF? SWE has the lower MAC address so the port from SWG to SWE would win the forwarding election. Therefore, answer B could never be correct.
Q198. Which two statements about class maps are true? (Choose two.)
A. As many as eight DSCP values can be included in a match dscp statement.
B. The default parameter on a class map with more than one match command is match-any.
C. The match class command can nest a class map within another class map.
D. A policy map can be used to designate a protocol within a class map.
Answer: A,C
Explanation:
Answer A.
Router(config-cmap)# match [ip] dscp dscp-value [dscp-value dscp-value dscp-value
dscp-value dscp-value dscp-value dscp-value]
(Optional) Identifies a specific IP differentiated service code point (DSCP) value as a match criterion. Up to eight DSCP values can be included in one match statement.
Answer C.
Router config-cmap)# match class-map class-name (Optional) Specifies the name of a traffic class to be used as a matching criterion (for nesting traffic class [nested class maps] within one another).
Reference: http://www.cisco.com/c/en/us/td/docs/ios/12_2/qos/configuration/guide/fqos_c/qcfmcli2.html
Q199. Refer to the exhibit.
R3 prefers the path through R1 to reach host 10.1.1.1.
Which option describes the reason for this behavior?
A. The OSPF reference bandwidth is too small to account for the higher speed links through R2.
B. The default OSPF cost through R1 is less than the cost through R2.
C. The default OSPF cost through R1 is more than the cost through R2.
D. The link between R2 and R1 is congested.
Answer: A
Explanation:
The default formula to calculate OSPF bandwidth is BW = Bandwidth Reference / interface
bandwidth [bps] = 10^8 / / interface bandwidth [bps]
BW of the R1-R3 link = 10^8 / 100Mbps = 10^8 / 10^8 = 1
BW of the R2-R3 link = 10^8 / 1Gbps = 10^8 / 10^9 = 1 (round up)
Therefore OSPF considers the two above links have the same Bandwidth -> R3 will go to 10.1.1.1 via the R1-R3 link. The solution here is to increase the Bandwidth Reference to a higher value using the “auto-cost reference-bandwidth” command under OSPF router mode. For example: Router(config)#router ospf 1 Router(config-router)#auto-cost reference-bandwidth 10000 This will increase the reference bandwidth to 10000 Mbps which increases the BW of the R2-R3 link to 10^10 / 10^8 = 100.
Q200. Which option describes how a VTPv3 device responds when it detects a VTPv2 device on a trunk port?
A. It sends VTPv3 packets only.
B. It sends VTPv2 packets only.
C. It sends VTPv3 and VTPv2 packets.
D. It sends a special packet that contains VTPv3 and VTPv2 packet information.
Answer: C
Explanation:
When a VTP version 3 device on a trunk port receives messages from a VTP version 2 device, the VTP version 3 device sends a scaled-down version of the VLAN database on that particular trunk in a VTP version 2 format. A VTP version 3 device does not send out VTP version 2-formatted packets on a trunk port unless it first receives VTP version 2 packets on that trunk. If the VTP version 3 device does not receive VTP version 2 packets for an interval of time on the trunk port, the VTP version 3 device stops transmitting VTP version 2 packets on that trunk port. Even when a VTP version 3 device detects a VTP version 2 device on a trunk port, the VTP version 3 device continues to send VTP version 3 packets in addition to VTP version 3 device 2 packets, to allow two kinds of neighbors to coexist on the trunk. VTP version 3 sends VTP version 3 and VTP version 2 updates on VTP version 2-detected trunks.
Reference: http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst6500/ios/12-2SX/configuration/guide/book/vtp.html