Pass4sure offers free demo for 640-878 exam. "Building Cisco Service Provider Next-Generation Networks, Part 2", also known as 640-878 exam, is a Cisco Certification. This set of posts, Passing the Cisco 640-878 exam, will help you answer those questions. The 640-878 Questions & Answers covers all the knowledge points of the real exam. 100% real Cisco 640-878 exams and revised by experts!


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Q1. Refer to the partial Cisco IOS XR BGP configuration exhibit. 

***Exhibit is Missing*** 

Which two statements are true? (Choose two) 

A. This router uses its Loopback 0 interface IP address when establishing BGP peering with the 

10.2.1.1 router. 

B. This router uses its Loopback 0 interface IP address when establishing BGP peering with the 

192.168.101.11 router. 

C. Test1 refers to a route policy that is defined using the RPL. 

D. Both the IBGP and EBGP sessions will be authenticated. 

E. The IBGP session is missing the mandatory route-policy configuration. 

Answer: A,C 

Q2. ISPs use which protocol to establish peering sessions in an Internet exchange point environment? 

A. LDP 

B. IS-IS 

C. BGP 

D. OSPF 

Answer: C 

Q3. Refer to the configuration example exhibit. 

***Exhibit is Missing*** 

Which statement is true? 

A. A trunk port has been created and VLAN has been allowed. 

B. An access port has been created on a UNI. 

C. A customer VLAN of 209 is configured. 

D. A QinQ VLAN of 118 is configured. 

Answer: D 

Q4. 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: A,B 

Q5. You want to configure HSRP between a Cisco IOS and a Cisco IOS XR router for the 192.0.2.0/24 subnet. Half of the PCs on the 192.0.2.0/24 subnet are configured to use 192.0.2.1 as the default gateway, and the other half of the PCs are configured to use 192.0.2.254 as the default gateway. The intent is to load balance the traffic across both routers. 

Which two IOS and IOS XR configurations are needed? (Choose two.) 

A. 

! IOS-XR interface GigabitEthernet 0/0/0/0 ip address 192.0.2.3 255.255.255.0 router hsrp interface GigabitEthernet 0/0/0/0 hsrp 1 ipv4 192.0.2.1 hsrp 1 priority 95 hsrp 1 preempt hsrp 2 ipv4 192.0.2.254 hsrp 2 priority 105 hsrp 2 preempt 

B. 

! IOS-XR interface GigabitEthernet 0/0/0/0 ip address 192.0.2.1 255.255.255.0 router hsrp interface GigabitEthernet 0/0/0/0 hsrp 1 ipv4 192.0.2.1 hsrp 1 priority 99 hsrp 1 preempt hsrp 2 ipv4 192.0.2.254 hsrp 2 priority 101 hsrp 2 preempt 

C. 

! IOS-XR interface GigabitEthernet 0/0/0/0 ip address 192.0.2.3 255.255.255.0 router hsrp interface GigabitEthernet 0/0/0/0 hsrp 1 ipv4 192.0.2.1 hsrp 1 priority 1 hsrp 1 preempt hsrp 2 ipv4 192.0.2.254 hsrp 2 priority 1 hsrp 2 preempt 

D. 

! IOS interface GigabitEthernet 0/0 ip address 192.0.2.2 255.255.255.0 standby 1 ip 192.0.2.1 standby 1 priority 105 standby 1 preempt standby 2 ip 192.0.2.254 standby 2 priority 95 standby 2 preempt ! IOS interface GigabitEthernet 0/0 ip address 192.0.2.254 255.255.255.0 standby 1 ip 192.0.2.1 standby 1 preempt standby 2 ip 192.0.2.254 standby 2 preempt 

E. 

! IOS interface GigabitEthernet 0/0 ip address 192.0.2.2 255.255.255.0 standby 1 ip 192.0.2.1 standby 1 preempt standby 1 priority 2 standby 2 ip 192.0.2.254 standby 2 preempt standby 2 priority 2 

Answer: A,D 

Q6. Refer to the Cisco IOS XR commands exhibit. 

***Exhibit is Missing*** 

The router administrator is trying to activate a software package on the router but is not able to do so. Which statement about this problem is true? 

A. The router needs to be in the global configuration mode. 

B. The router needs to be in the admin global configuration mode. 

C. The router needs to be in the admin EXEC mode. 

D. The install activate command is not the correct command to use. 

E. The administrator needs to log in as the "root" user instead of the "admin" user. 

Answer: C 

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 

Q7. Which two statements about NAT64 are true? (Choose two.) 

A. NAT64 packets traverse two IPv4 addressing domains. 

B. NAT64 packets are translated two times. 

C. There are two types of NAT64 (stateful or stateless). 

D. NAT is performed by the CPE and also by the service provider edge router. 

E. The DNS64 server embeds the IPv4 address from the DNS A record with a preconfigured IPv6 translation prefix. 

Answer: C,E 

Q8. You are enabling OSPF on a router and notice that all the Fast Ethernet and the Gigabit Ethernet interfaces have the same OSPF cost of 1. Which single configuration change can you make in router ospf configuration mode so that the Fast Ethernet interfaces have a higher OSPF cost than the Gigabit Ethernet interfaces? 

A. Change the OSPF interface cost globally. 

B. Change the OSPF default metric. 

C. Change the OSPF auto-cost reference bandwidth. 

D. Change the OSPF administrative distance. 

E. Change the OSPF metric type from E2 to E1. 

Answer: C 

On Cisco IOS XR software, which set of commands enables OSPF area 0 on the Gi0/0/0/0 interface that has an IPv4 IP address of 192.168.1.1/24? 

A. router ospf 1 network 192.168.1.1 0.0.0.0 area 0 router ospf 1 network 192.168.1.1 255.255.255.255 area 0 router ospf 1 area 0 

B. interface gi0/0/0/0 router ospfv3 1 network 192.168.1.1 0.0.0.0 area 0 router ospfv3 1 network 192.168.1.1 255.255.255.255 area 0 router ospfv3 1 area 0 

C. network 192.168.1.0 router ospfv3 1 area 0 

D. interface gi0/0/0/0 

Q9. Refer to the partial configurations exhibit. 

***Exhibit is Missing*** 

What additional configurations are 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 Fa0/1 ip address 192.168.10.1 255.255.255.0 ! interface Fa0/2 ip address 192.168.20.1 255.255.255.0 ! 

B. interface Fa0/1 ip address 192.168.10.1 255.255.255.0 ! interface Fa0/2 ip address 192.168.20.1 255.255.255.0 ! 

C. router eigrp 1 network 192.168.10.0 network 192.168.20.0 ! 

D. interface vlan 10 ip address 192.168.10.1 255.255.255.0 ! interface vlan 20 ip address 192.168.20.1 255.255.255.0 ! 

E. interface Fa0/1 encapsulation dot1q 10 ip address 192.168.10.1 255.255.255.0 ! interface Fa0/2 encapsulation dot1q 20 ip address 192.168.20.1 255.255.255.0 ! 

Answer: C 

Q10. Which four statements about REP configurations on a Cisco ME 3400 switch port are true? 

 (Choose four.) 

A. The port must be an NNI type and must be in trunk mode. 

B. Use the rep segment number command to enable REP on the switch port. 

C. A REP segment cannot be wrapped into a ring topology. REP supports only a topology where each REP segment has two exit points via two edge switches. 

D. The port where the segment terminates is called the edge port. 

E. With REP, at least one port is always blocked in any given segment-that is, the alternate port. 

F. If a failure occurs within the segment, the blocked port goes to the forwarding state after it goes through the listening state and the learning state. 

Answer: A,B,D,E