Certified 640-878 Preparation Exams 2021

NEW QUESTION 1





Hot Area:

• A. Mastered
• B. Not Mastered

Answer: A

Explanation:

Priority 32768 and MAC address e8ba.70b5.6c00
Use the "show spanning-tree mst" command on each switch to find the root port and the priority.

NEW QUESTION 2





Hot Area:

• A. Mastered
• B. Not Mastered

Answer: A

Explanation:

S78 port Fa0/23
Use the "show spanning-tree mst" command on each switch to find the port status that shows BLK for VLAN 70.

NEW QUESTION 3
Select and Place:

• A. Mastered
• B. Not Mastered

Answer: A

Explanation:

NEW QUESTION 4
Select and Place:

• A. Mastered
• B. Not Mastered

Answer: A

Explanation:

NEW QUESTION 5
What layer of the IP NGN Model does the Customer Element and the Carrier Ethernet exist?

• A. Service Layer
• B. Network Layer
• C. Application Layer
• D. Operational Layer

Answer: B

NEW QUESTION 6
Which spanning-tree mode uses the name command to configure a region name?

• A. MST
• B. PVST+
• C. PVRST+
• D. RSTP

Answer: A

NEW QUESTION 7
Refer to the partial Cisco IOS-XR configuration. What is the purpose of the for PFX to PEER command?
!
mpls ldp label advertise
disable
for PFX to PEER
!<output omitted>
!

• A. To selectively enable LDP peering(s) with specific neighbors
• B. To selectively disable LDP peering(s) with specific neighbors
• C. To perform outbound filtering for local label advertisement for one or more prefixes to one or more peers
• D. To perform inbound filtering for local label advertisement for one or more prefixes from one or more peers

Answer: C

NEW QUESTION 8





Hot Area:

• A. Mastered
• B. Not Mastered

Answer: A

Explanation:

vlan 80
Use the "show spanning-tree mst" command on each switch to see the vlans mapped to each MST.

NEW QUESTION 9
Which two statements about carrier-grade NAT are true? (Choose two.)

• A. It conserves IPv4 addresses.
• B. A service provider issues private IP addresses to its customers.
• C. A service provider translates the private IP address of its customer to another private IP address.
• D. It is implemented on the CE and PE routers.
• E. It is designed to simplify IPv6 addressing.

Answer: AB

Explanation:
http://www.cisco.com/en/US/docs/routers/crs/software/crs_r3.9.1/cg_nat/configuration/guide/cgc39 1cgn.html#wp1268988
Carrier Grade NAT Overview
Carrier Grade Network Address Translation (CGN) is a large scale NAT that is capable of providing private IPv4 to public IPv4 translation in the order of millions of translations to support several hundred thousand subscribers and bandwidth throughput of at least 10 Gbps full-duplex.
CGN is a workable solution to the IPv4 address depletion problem while offering a way for service provider subscribers and content providers to implement a graceful transition to IPv6. CGN employs network address and port translation (NAPT) methods to aggregate many private IP addresses into fewer public IPv4 addresses. For example, a single public IPv4 address with a pool of 32 K port numbers supports 320 individual private IP subscribers assuming each subscriber requires 100 ports (for example, each TCP connection needs one port number). A CGN requires IPv6 to assist with the transition from IPv4 to IPv6.

NEW QUESTION 10
Which statement is true about enabling IS-IS routing and using the net command to configure the NSAP address?

• A. NSAP addresses have a fixed size of 20 bytes.
• B. The NSEL must always be 00 to identify the router.
• C. The area address follows the system ID field before the NSEL field.
• D. An AFI of 39 indicates that the AFI is a locally administered private address.

Answer: B

Explanation:
http://www.cisco.com/en/US/tech/tk365/technologies_white_paper09186a00800a3e6f.shtml

NEW QUESTION 11
Select and Place:

• A. Mastered
• B. Not Mastered

Answer: A

Explanation:

NEW QUESTION 12
On Cisco IOS XR software, what is the default commit option?

• A. best-effort
• B. psuedo-atomic
• C. replace
• D. force

Answer: B

Explanation:

NEW QUESTION 13
Refer to the configuration output below. OSPFv2 is already configured on a customer router and the customer is requesting that OSPFv3 be added. What configuration is needed in order to add OSPFv3 to the fastethernet0/0 interface?
Configuration: ipv6 router ospf 1
router-id 209.165.200.227
area 2 nssa
interface fastethernet0/0
ip address 2001:DB8:0:7::

• A. interface FastEthernet0/0 ipv4 ospf 1 area 2
• B. interface FastEthernet0/0 ipv6 ospf 1 area 2
• C. interface FastEthernet0/0 ipv6 1 area 2
• D. interface FastEthernet0/0 area 2 ospf 1 ipv6

Answer: B

NEW QUESTION 14
Which three are correct statements based on the BGP configuration below? (Choose three.)
Router#config t Router(config)#router bgp 1
Router(config-router)#neighbor 1.1.1.1 remote-as 1
Router(config-router)#neighbor 3.3.3.3 remote-as 2

• A. local AS is 1
• B. local AS is 2
• C. neighbor 1.1.1.1 remote-as 1 is iBGP peer
• D. neighbor 1.1.1.1 remote-as 1 is eBGP peer
• E. neighbor 3.3.3.3 remote-as 2 is iBGP peer
• F. neighbor 3.3.3.3 remote-as 2 is eBGP peer
• G. neighbor 2.2.2.2 remote-as 2 is iBGP peer
• H. neighbor 2.2.2.2 remote-as 2 is eBGP peer

Answer: ACF

NEW QUESTION 15
Which three statements about access control lists on a Cisco IOS router are true? (Choose three)

• A. The more specific ACL entries should be placed at the top of the ACL.
• B. The generic ACL entries should be placed at the top of the ACL, to filter general traffic and reduce noise on the network.
• C. ACLs always search for the most specific entry before taking any filtering action.
• D. Router-generated packets cannot be filtered by the interface ACLs on the router.
• E. Extended ACLs should be placed as close to the destination as possible.
• F. There must be at least one permit statement in an ACL, or all traffic is denied.

Answer: ADF

NEW QUESTION 16
Which command configures a switchport to connect only a host device in VLAN 301?

• A. switchport access vlan 301
• B. switchport mode trunk vlan 301
• C. switchport mode access vlan 301
• D. switchport vlan 301

Answer: A

NEW QUESTION 17
What is the advantage of running IOS-XE individual consolidated packages versus subpackages?

• A. decreases storage requirements
• B. optimizes router memory usage
• C. simplified installation
• D. lowers CPU utilization

Answer: B

NEW QUESTION 18
Refer to the configuration snippet below. A new IOS-XR router is being added to the network. What command is required to enable the Label Distribution Protocol on interface GigabitEthernet 0/3/0/0?
Configuration: mpls ldp
router-id 209.165.200.226

• A. interface GigabitEthernet0/3/0/0
• B. mpls ldpinterface GigabitEthernet0/3/0/0
• C. interface GigabitEthernet0/3/0/0 ldp enable
• D. ldpinterface GigabitEthernet0/3/0/0

Answer: B

NEW QUESTION 19
When upgrading a Cisco ASR 1001 Router, when is the request platform software package expand file bootflash:image-name command required?

• A. to copy the consolidated Cisco IOS XE image to the bootflash:
• B. to perform Cisco IOS ISSU on the standby route processor
• C. to run the router using a consolidated package
• D. to run the router using individual subpackages

Answer: D

Explanation:
http://www.cisco.com/en/US/docs/routers/asr1000/configuration/guide/chassis/asrswcfg.pdf

NEW QUESTION 20
Refer to the exhibit.

What additional configuration is required to enable inter-VLAN routing for VLANs 10 and 20 on the Cisco ME 3400 switch using the Metro IP Access image?

• A. interface Fa0/1ip address 192.168.10.1 255.255.255.0!interface Fa0/2ip address 192.168.20.1 255.255.255.0!
• B. interface Fa0/1ip address 192.168.10.1 255.255.255.0!interface Fa0/2ip address 192.168.20.1 255.255.255.0!router eigrp 1network 192.168.10.0network 192.168.20.0!
• C. interface vlan 10ip address 192.168.10.1 255.255.255.0!interface vlan 20ip address 192.168.20.1 255.255.255.0!
• D. interface Fa0/1 encapsulation dot1q 10ip address 192.168.10.1 255.255.255.0!interface Fa0/2 encapsulation dot1q 20ip address 192.168.20.1 255.255.255.0!

Answer: C

NEW QUESTION 21
What feature of the Cisco ASR series enables service providers and enterprise customers to manage their network performance with respect to bandwidth, delay, jitter, and packet loss?

• A. power over ethernet
• B. quality of service architecture
• C. ip sla
• D. layer 3 capability

Answer: B

NEW QUESTION 22

• A. Mastered
• B. Not Mastered

Answer: A

Explanation:
Here is the solution.
conf t
int loopback 0 no shut
ipv4 address 10.7.1.1 255.255.255.255
ipv6 address 2001:db8:10:7:1::1/128 int Gi0/0/0/1
no shut
ipv4 address 192.168.178.70 255.255.255.0 ipv6 address 2001:DB8:192:168:178::70/64
commit
router bgp 65001
address-family ipv4 unicast redistribute connected neighbor 10.8.1.1
remote-as 65001
update-source loopback 0 commit
exit
address family ipv6 unicast redistribute connected neighbor 2001:db8:10:8:1::1 remote-as 65001
update-source loopback 0 commit

NEW QUESTION 23
What are three common problems related to sessions not establishing between iBGP neighbors? (Choose three.)

• A. Incorrect MAC-address configured
• B. Unable to reach IP
• C. Network is not configured under router bgp x configuration
• D. Access list
• E. Firewall blocking all TCP traffic
• F. Redistribution is not configured under router bgp x configuration

Answer: BDE

NEW QUESTION 24
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