Flashcards in WAN Deck (21)
Which command can you enter to determine whether serial interface 0/2/0 has been configured using HDLC encapsulation?
A. router#show platform
B. router#show ip interface s0/2/0
C. router#show interfaces Serial 0/2/0
D. router#show ip interface brief
Which Layer 2 protocol encapsulation type supports synchronous and asynchronous circuits and has built-in security mechanisms?
D. Frame Relay
Which statements about using leased lines for your WAN infrastructure are true?
A. Leased lines provide inexpensive WAN access.
B. Leased lines with sufficient bandwidth can avoid latency between endpoints.
C. Leased lines require little installation and maintenance expertise.
D. Leased lines provide highly flexible bandwidth scaling.
E. Multiple leased lines can share a router interface.
F. Leased lines support up to T1 link speeds.
Answer: B C
Two routers named Atlanta and Brevard are connected by their serial interfaces as illustrated, but there is no connectivity between them. The Atlanta router is known to have a correct configuration. Given the partial configurations, identify the problem on the Brevard router that is causing the lack of connectivity.
A. transmission unit size too large
B. no loopback set
C. an incorrect subnet mask
D. incompatible encapsulation at each end
E. an incorrect IP address F. incompatible bandwidth between routers
Which of the following describes the roles of devices in a WAN? (Choose three)
A. A CSU/DSU terminates a digital local loop
B. A modem terminates a digital local loop
C. A CSU/DSU terminates an analog local loop
D. A modem terminates an analog local loop
E. A router is commonly considered a DTE device
F. A router is commonly considered a DCE device
Answers: A D E
Which two pieces of information are provided by the “show controllers serial 0” command? (Choose two)
A. the type of cable that is connected to the interface.
B. The uptime of the interface
C. the status of the physical layer of the interface
D. the full configuration of the interface
E. the interface‟s duplex settings
Answer: A C
Which command is used to know the duplex speed of serial link?
A. show line
B. show interface
C. show protocol
D. show run
Which WAN topology provides a direct connection from each site to all other sites on the network?
B. full mesh
What are three reasons that an organization with multiple branch offices and roaming users might implement a Cisco VPN solution instead of point-to-point WAN links? (Choose three)
A. reduced cost
B. better throughput
C. broadband incompatibility
D. increased security
F. reduced latency
Answer: A D E
Which three statements about DWDM are true? (Choose three)
A. It allows a single strand of fiber to support bidirectional communications
B. It is used for long-distance and submarine cable systems
C. It can multiplex up to 256 channels on a single fiber
D. It supports both the SDH and SONET standards
E. Each channel can carry up to a 1-Gbps signal F. It supports simplex communications over multiple strands of fiber
Answer: A B D
Which PPP subprotocol negotiates authentication options?
In GLBP, which router will respond to client ARP requests?
A. The active virtual gateway will reply with one of four possible virtual MAC addresses.
B. All GLBP member routers will reply in round-robin fashion.
C. The active virtual gateway will reply with its own hardware MAC address.
D. The GLBP member routers will reply with one of four possible burned in hardware addresses.
Correct Answer: A Section: WAN Technologies
Which statement describes VRRP object tracking?
A. It monitors traffic flow and link utilization.
B. It ensures the best VRRP router is the virtual router master for the group.
C. It causes traffic to dynamically move to higher bandwidth links.
D. It thwarts man-in-the-middle attacks.
Correct Answer: B Section: WAN Technologies
What OSPF command, when configured, will include all interfaces into area 0?
A. network 0.0.0.0 255.255.255.255 area 0
B. network 0.0.0.0 0.0.0.0 area 0
C. network 255.255.255.255 0.0.0.0 area 0
D. network all-interfaces area 0
Correct Answer: A Section: WAN Technologies
Which statement describes the process ID that is used to run OSPF on a router?
A. It is globally significant and is used to represent the AS number.
B. It is locally significant and is used to identify an instance of the OSPF database.
C. It is globally significant and is used to identify OSPF stub areas.
D. It is locally significant and must be the same throughout an area.
Correct Answer: B Section: WAN Technologies
Which two statements about the OSPF Router ID are true? (Choose two.)
A. It identifies the source of a Type 1 LSA.
B. It should be the same on all routers in an OSPF routing instance.
C. By default, the lowest IP address on the router becomes the OSPF Router ID.
D. The router automatically chooses the IP address of a loopback as the OSPF Router ID.
E. It is created using the MAC Address of the loopback interface.
Correct Answer: AD Section: WAN Technologies
What are two benefits of using a single OSPF area network design? (Choose two.)
A. It is less CPU intensive for routers in the single area.
B. It reduces the types of LSAs that are generated.
C. It removes the need for virtual links.
D. It increases LSA response times.
E. It reduces the number of required OSPF neighbor adjacencies.
Correct Answer: BC Section: WAN Technologies
What are the benefit of using Netflow? (Choose three.)
A. Network, Application & User Monitoring
B. Network Planning
C. Security Analysis
Correct Answer: ACD Section: Mix Questions
Explanation: NetFlow Definitions and Benefits Reference: http://www.cisco.com/en/US/products/sw/netmgtsw/ps1964/products_implementation_design_guide0918 6a00800d6a11.html#wp1030045 Explanation: NetFlow traditionally enables several key customer applications including: Network Monitoring–NetFlow data enables extensive near real time network monitoring capabilities. Flowbased analysis techniques may be utilized to visualize traffic patterns associated with individual routers and switches as well as on a network-wide basis (providing aggregate traffic or application based views) to provide proactive problem detection, efficient troubleshooting, and rapid problem resolution.Application Monitoring and Profiling–NetFlow data enables network managers to gain a detailed, timebased, view of application usage over the network. This information is used to plan, understand new services, and allocate network and application resources (e.g. Web server sizing and VoIP deployment) to responsively meet customer demands. User Monitoring and Profiling–NetFlow data enables network engineers to gain detailed understanding of customer/user utilization of network and application resources. This information may then be utilized to efficiently plan and allocate access, backbone and application resources as well as to detect and resolve potential security and policy violations. Network Planning–NetFlow can be used to capture data over a long period of time producing the opportunity to track and anticipate network growth and plan upgrades to increase the number of routing devices, ports, or higher- bandwidth interfaces. NetFlow services data optimizes network planning including peering, backbone upgrade planning, and routing policy planning. NetFlow helps to minimize the total cost of network operations while maximizing network performance, capacity, and reliability. NetFlow detects unwanted WAN traffic, validates bandwidth and Quality of Service (QOS) and allows the analysis of new network applications. NetFlow will give you valuable information to reduce the cost of operating your network. Security Analysis–NetFlow identifies and classifies DDOS attacks, viruses and worms in real- time. Changes in network behavior indicate anomalies that are clearly demonstrated in NetFlow data. The data is also a valuable forensic tool to understand and replay the history of security incidents.Accounting/Billing–NetFlow data provides fine-grained metering (e.g. flow data includes details such as IP addresses, packet and byte counts, timestamps, type- of-service and application ports, etc.) for highly flexible and detailed resource utilization accounting. Service providers may utilize the information for billing based on time-of-day, bandwidth usage, application usage, quality of service, etc. Enterprise customers may utilize the information for departmental charge- back or cost allocation for resource utilization.NetFlow Data Warehousing and Data Mining–NetFlow data (or derived information) can be warehoused for later retrieval and analysis in support of proactive marketing and customer service programs (e.g. figure out which applications and services are being utilized by internal and external users and target them for improved service, advertising, etc.). In addition, NetFlow data gives Market Researchers access to the “who”, “what”, “where”, and “how long” information relevant to enterprises and service providers.
What are three benefits of GLBP? (Choose three.)
A. GLBP supports up to eight virtual forwarders per GLBP group.
B. GLBP supports clear text and MD5 password authentication between GLBP group members.
C. GLBP is an open source standardized protocol that can be used with multiple vendors.
D. GLBP supports up to 1024 virtual routers.
E. GLBP can load share traffic across a maximum of four routers.
F. GLBP elects two AVGs and two standby AVGs for redundancy.
Correct Answer: BDE Section: Mix Questions
Explanation: http://www.cisco.com/en/US/docs/ios/12_2s/feature/guide/fs_glbp2.html Load Sharing You can configure GLBP in such a way that traffic from LAN clients can be shared by multiple routers, thereby sharing the traffic load more equitably among available routers. Multiple Virtual Routers GLBP supports up to 1024 virtual routers (GLBP groups) on each physical interface of a router, and up to four virtual forwarders per group. Preemption The redundancy scheme of GLBP enables you to preempt an active virtual gateway with a higher priority backup virtual gateway that has become available. Forwarder preemption works in a similar way, except that forwarder preemption uses weighting instead of priority and is enabled by default. Authentication You can use a simple text password authentication scheme between GLBP group members to detect configuration errors. A router within a GLBP group with a different authentication string than other routers will be ignored by other group members. http://www.cisco.com/en/US/docs/switches/datacenter/sw/5_x/nx- s/unicast/configuration/guide/l3_glbp.html Explanation: GLBP Authentication ; GLBP has three authentication types: MD5 authentication Plain text authentication No authentication MD5 authentication provides greater security than plain text authentication. MD5 authentication allows each GLBP group member to use a secret key to generate a keyed MD5 hash that is part of the outgoing packet. At the receiving end, a keyed hash of an incoming packet is generated. If the hash within the incoming packet does not match the generated hash, the packet is ignored. The key for the MD5 hash can either be given directly in the configuration using a key string or supplied indirectly through a key chain. You can also choose to use a simple password in plain text to authenticate GLBP packets, or choose no authentication for GLBP.
What is the purpose of LCP?
A. to perform authentication
B. to negotiate control options
C. to encapsulate multiple protocols
D. to specify asynchronous versus synchronous
Correct Answer: B Section: Mix Questions
Explanation: Link Control Protocol http://www.ietf.org/rfc/rfc1661.txt In order to be sufficiently versatile to be portable to a wide variety of environments, PPP provides a Link Control Protocol (LCP). The LCP is used to automatically agree upon the encapsulation format options, handle varying limits on sizes of packets, detect a looped- back link and other common misconfiguration errors, and terminate the link. Other optional facilities provided are authentication of the identity of its peer on the link, and determination when a link is functioning properly and when it is failing.