400-101 Exam - CCIE Routing and Switching (v5.0)

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Q1. Refer to the exhibit. 

ASN 64523 has a multihomed BGP setup to ISP A and ISP B. Which BGP attribute can you set to allow traffic that originates in ASN 64523 to exit the ASN through ISP B? 

A. origin 

B. next-hop 

C. weight 

D. multi-exit discriminator 

Answer:

Explanation: 

MED is an optional nontransitive attribute. MED is a hint to external neighbors about the preferred path into an autonomous system (AS) that has multiple entry points. The MED is also known as the external metric of a route. A lower MED value is preferred over a higher value. Example at reference link below: 

Reference: http://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13759-37.html 

Q2. Refer to the exhibit. 

Which statement about the debug behavior of the device is true? 

A. The device debugs all IP events for 172.16.129.4. 

B. The device sends all debugging information for 172.16.129.4. 

C. The device sends only NTP debugging information to 172.16.129.4. 

D. The device sends debugging information every five seconds. 

Answer:

Explanation: 

This is an example of a conditional debug, where there is a single condition specified of IP address 172.16.129.4. So, all IP events for that address will be output in the debug. 

Q3. DRAG DROP 

Drag and drop the MPLS term on the left to the function it performs on the right. 

Answer:  

Q4. Which two statements about path selection are true? (Choose two.) 

A. If there are multiple equal matches between OSPF processes, the path with the lowest OSPF PID is chosen. 

B. If the backdoor command is configured on a BGP network, the route is advertised with an AD of 20. 

C. If an OSPF E2 route has an AS of 90, that path is preferred over an OSPF IA route with an AD of 110. 

D. If there are multiple equal matches between the same protocols on an EIGRP network, the preferred path will be EIGRP with the highest AS. 

E. If IS-IS has multiple routes with the same prefix-length, it will prefer Level 1 routes over Level 2 routes. 

Answer: A,E 

Q5. Which two parameters does the Tunnel Mode Auto Selection feature select automatically? (Choose two.) 

A. the tunneling protocol 

B. the transport protocol 

C. the ISAKMP profile 

D. the transform-set 

E. the tunnel peer 

Answer: A,B 

Explanation: 

The Tunnel Mode Auto Selection feature eases the configuration and spares you about knowing the responder’s details. This feature automatically applies the tunneling protocol (GRE or IPsec) and transport protocol (IPv4 or IPv6) on the virtual template as soon as the IKE profile creates the virtual access interface. This feature is useful on dual stack hubs aggregating multivendor remote access, such as Cisco AnyConnect VPN Client, Microsoft Windows7 Client, and so on. 

Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/sec_conn_vpnips/configuration/xe-3s/sec-sec-for-vpns-w-ipsec-xe-3s-book/sec-ipsec-virt-tunnl.html 

Q6. Which three statements about SPAN traffic monitoring are true? (Choose three.) 

A. Traffic from a non-source VLAN is discarded when it arrives on a source VLAN. 

B. Multiple sessions can send traffic to an individual destination port. 

C. It supports up to 32 SPAN ports per switch. 

D. The destination port acts as a normal switchport. 

E. It supports up to 64 SPAN ports per switch. 

F. Only one session can send traffic to an individual destination port. 

Answer: A,E,F 

Explanation: 

You can create up to a total of 64 SPAN and ERSPAN sessions to define sources and destinations on the local device.You can also create a SPAN session to monitor multiple VLAN sources and choose only VLANs of interest to transmit on multiple destination ports. 

For example, you can configure SPAN on a trunk port and monitor traffic from different VLANs on different destination ports. 

You can configure a particular destination port in only one SPAN session. 

Traffic from a non-source VLAN is discarded when it arrives on a source VLAN. 

Reference: 

http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus1000/sw/4_0/troubleshooti 

ng/configuration/guide/n1000v_troubleshooting/trouble_15span.html 

Q7. Refer to the exhibit. 

If the route to 10.1.1.1 is removed from the R2 routing table, which server becomes the master NTP server? 

A. R2 

B. the NTP server at 10.3.3.3 

C. the NTP server at 10.4.4.4 

D. the NTP server with the lowest stratum number 

Answer:

Explanation: 

NTP uses a concept called “stratum” that defines how many NTP hops away a device is from an authoritative time source. For example, a device with stratum 1 is a very accurate device and might have an atomic clock attached to it. Another NTP server that is using this stratum 1 server to sync its own time would be a stratum 2 device because it’s one NTP hop further away from the source. When you configure multiple NTP servers, the client will prefer the NTP server with the lowest stratum value. 

Reference: https://networklessons.com/network-services/cisco-network-time-protocol-ntp/ 

Q8. Which two statements about NetFlow are true? (Choose two.) 

A. It must be configured on each router in a network. 

B. It supports ATM LAN emulation. 

C. The existing network is unaware that NetFlow is running. 

D. It uses SIP to establish sessions between neighbors. 

E. It provides resource utilization accounting. 

Answer: C,E 

Explanation: 

NetFlow identifies packet flows for both ingress and egress IP packets. It does not involve any connection-setup protocol, either between routers or to any other networking device or end station. NetFlow does not require any change externally--either to the packets themselves or to any networking device. NetFlow is completely transparent to the existing network, including end stations and application software and network devices like LAN switches. Also, NetFlow capture and export are performed independently on each internetworking device; NetFlow need not be operational on each router in the network. NetFlow data provides fine-grained metering for highly flexible and detailed resource utilization accounting. For example, flow data includes details such as IP addresses, packet and byte counts, timestamps, type-of-service, and application ports. Service providers might utilize the information for billing based on time-of-day, bandwidth usage, application usage, or quality of service. Enterprise customers might utilize the information for departmental chargeback or cost allocation for resource utilization. 

Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/netflow/configuration/12-4t/nf-12-4t-book/ios-netflow-ov.html 

Q9. Which statement about passive interfaces is true? 

A. The interface with the OSPF passive interface configuration appears as a not-so-stubby network. 

B. The interface with the EIGRP passive interface configuration ignores routes after the exchange of hello packets. 

C. The interface with the IS-IS passive interface configuration sends the IP address of that interface in the link-state protocol data units. 

D. Passive interface can be configured on the interface for IS-IS. 

Answer:

Explanation: 

With IS-IS, passive interfaces are used to prevent unnecessary LSA packets out that interface, but the IP address of passive interfaces are still included in updates going out the other interfaces. This behavior is what enables the best practice of configuring loopback interfaces as passive, but still having the loopback be reachable. 

Q10. Refer to the exhibit. 

If OSPF is implemented on the network, which additional configuration is needed to allow traffic from host 10.4.1.15/24 to host 10.1.2.20/24? 

A. A virtual link between router 2 and router 4 

B. A virtual link between router 3 and router 4 

C. A virtual link between router 2 and router 3 

D. The current design allows traffic between the two hosts. 

Answer:

Explanation: 

This specific traffic from 10.4.1.0/24 to 10.1.2.0/24 would work because this traffic crosses only over the single OSPF area of 0.0.0.1. 

However, traffic from hosts on R4 to R1 would indeed need a virtual link, since area 0.0.0.2 is not connected to the backbone area of 0.0.0.0.