Q131. Refer to the exhibit.
A PE router is configured with a policy map that contains the policer shown. The policy map is configured in the inbound direction of an interface facing a CE router. If the PE router
receives 12Mb/s of traffic with the CoS value set to 7 on a 100-Mb/s interface from the CE router, what value of MPLS EXP is set when this traffic goes through the policer shown?
A. 0
B. 6
C. 7
D. 8
Answer: B
Explanation:
Here, the policer is set where the conforming traffic is set to 10 percent of the 100 Mbps interface, so anything more than 10 Mbps will be placed into the exceeding traffic class, the traffic EXP value will be changed from 7 to 6 per the configuration.
Q132. Refer to the exhibit.
Which statement is true?
A. R1 routes this pseudowire over MPLS TE tunnel 1 with transport label 20.
B. The default route 0.0.0.0/0 is available in the IPv4 routing table.
C. R1 is using an MPLS TE tunnel for this pseudowire, because the IP path is not available.
D. R1 has preferred-path configured for the pseudowire.
Answer: D
Explanation:
Verifying the Configuration: Example In the following example, the show mpls l2transport vc command shows the following information (in bold) about the VCs:
. VC 101 has been assigned a preferred path called Tunnel1. The default path is disabled because the preferred path specified that the default path should not be used if the preferred path fails.
. VC 150 has been assigned an IP address of a loopback address on PE2. The default path can be used if the preferred path fails.
Router# show mpls l2transport vc detail
Local interface. Gi0/0/0.1 up, line protocol up, Eth VLAN 222 up
Destination address: 10.16.16.16, VC ID. 101, VC status: up
Preferred path: Tunnel1, active
Default path: disabled
Tunnel label: 3, next hop point2point
Output interfacE. Tu1, imposed label stack {17 16}
Create timE. 00:27:31, last status change timE. 00:27:31
Signaling protocol: LDP, peer 10.16.16.16:0 up
MPLS VC labels: local 25, remote 16
Group ID. local 0, remote 6
MTU: local 1500, remote 1500
Remote interface description:
Sequencing: receive disabled, send disabled
VC statistics:
packet totals: receive 10, send 10
byte totals: receive 1260, send 1300
packet drops: receive 0, send 0
Reference: http://www.cisco.com/c/en/us/td/docs/ios/12_2sr/12_2sra/feature/guide/srtunsel.html#wp10 57815
Q133. Which two DHCP messages are always sent as broadcast? (Choose two.)
A. DHCPOFFER
B. DHCPDECLINE
C. DHCPRELEASE
D. DHCPREQUEST
E. DHCPDISCOVER
Answer: D,E
Explanation:
DHCP discovery
The client broadcasts messages DHCPDISCOVER on the network subnet using the destination address 255.255.255.255 or the specific subnet broadcast address.
DHCP request
In response to the DHCP offer, the client replies with a DHCP request, broadcasts to the server, requesting the offered address. A client can receive DHCP offers from multiple servers, but it will accept only one DHCP offer.
Reference: http://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol
Q134. DRAG DROP
Drag each AF class on the left to its matching DSCP binary value on the right.
Answer:
Q135. Which two statements about reverse ARP are true? (Choose two.)
A. Its servers require static mappings.
B. It works with AutoInstall to configure new devices.
C. It provides IP addresses for subnet masks.
D. It provides IP addresses for default gateways.
E. It requires less maintenance than DHCP.
Answer: A,B
Q136. Which regular expression will match prefixes that originated from AS200?
A. ^$
B. ^200_
C. _200$ D. ^200)
E. _200_
Answer: C
Explanation:
Example on how to deny all prefixes originated in Autonomous System 200
router bgp 100
neighbor 10.1.1.1 remote-as 65535
neighbor 10.1.1.1 route-map map1 in
!
route-map map1 permit 10
match as-path 1
!
ip as-path access-list 5 deny _200$
ip as-path access-list 5 permit .*
Reference: http://www.cisco.com/c/en/us/td/docs/ios/termserv/configuration/guide/12_4t/tsv_12_4t_bo ok/tsv_reg_express.html
Q137. How many hash buckets does Cisco Express Forwarding use for load balancing?
A. 8
B. 16
C. 24
D. 32
Answer: B
Explanation:
In order to understand how the load balance takes place, you must first see how the tables relate. The Cisco Express Forwarding table points to 16 hash buckets (load share table), which point to the adjacency table for parallel paths. Each packet to be switched is broken up into the source and destination address pair and checked against the loadshare table.
Reference: http://www.cisco.com/c/en/us/support/docs/ip/express-forwarding-cef/18285-loadbal-cef.html
Q138. Which technology can create a filter for an embedded packet capture?
A. Control plane policing
B. Access lists
C. NBAR
D. Traffic shaping
Answer: B
Explanation:
A filter can be applied to limit the capture to desired traffic. Define an Access Control List (ACL) within config mode and apply the filter to the buffer:
ip access-list extended BUF-FILTER
permit ip host 192.168.1.1 host 172.16.1.1
permit ip host 172.16.1.1 host 192.168.1.1
monitor capture buffer BUF filter access-list BUF-FILTER
Reference: http://www.cisco.com/c/en/us/support/docs/ios-nx-os-software/ios-embedded-packet-capture/116045-productconfig-epc-00.html
Q139. Which congestion-avoidance or congestion-management technique can cause global synchronization?
A. Tail drop
B. Random early detection
C. Weighted random early detection
D. Weighted fair queuing
Answer: A
Explanation:
Tail Drop
Tail drop treats all traffic equally and does not differentiate between classes of service. Queues fill during periods of congestion. When the output queue is full and tail drop is in effect, packets are dropped until the congestion is eliminated and the queue is no longer full.
Weighted Random Early Detection
WRED avoids the globalization problems that occur when tail drop is used as the congestion avoidance mechanism on the router. Global synchronization occurs as waves of congestion crest only to be followed by troughs during which the transmission link is not fully utilized. Global synchronization of TCP hosts, for example, can occur because packets are dropped all at once. Global synchronization manifests when multiple TCP hosts reduce their transmission rates in response to packet dropping, then increase their transmission rates once again when the congestion is reduced.
Reference: http://www.cisco.com/c/en/us/td/docs/ios/12_2/qos/configuration/guide/fqos_c/qcfconav.ht ml#wp1002048
Q140. On a broadcast interface, which two OSPF states support BFD sessions? (Choose two.)
A. DR
B. BDR
C. DROTHER
D. 2WAY
E. FULL
F. ACTIVE
Answer: A,B