CCIE Written: WAN Switching

1.What is the primary benefit of the "time-to-live" field in the IP header?
A.To improve buffer utilization
B.To reduce the impact of routing loops
C.To allow calculation of round-trip delays
D.To remind us that all earthly joys are fleeting
E.To avoid delivery of packets that are no longer useful
Correct:B
2.A router interface address is 180.60.45.96 with a mask of 255.255.255.224. What configuration statement will allow this interface to participate in OSPF Area 0?
A.router ospf 1 network 180.60.45.96 255.255.255.32 area 0
B.router ospf 1 network 180.60.45.96 0.255.255.224 area 0
C.router ospf 1 network 180.60.45.96 0.0.0.31 area 0
D.router ospf 1 network 180.60.45.96 0.0.0.224 area 0
Correct:C
3.An IGX-8 identifies itself as an IGX-32 on the configuration screen. What has gone wrong?
A.The NPM was originally in an IGX-32.
B.Database corruption has occurred.
C.The user must physically set a jumper on the SCM to correct this.
D.Use the setnovram command to change the switch type.
Correct:C
4.In PNNI networks, AESA has the following general format:
A.12-byte network prefix plus a 7-byte End System Identifier plus 1 byte Selector
B.11-byte network prefix plus an 8-byte End System Identifier plus 1 byte Selector
C.7-byte network prefix plus a 12-byte End System Identifier plus 1 byte Selector.
D.13-byte network prefix, a 6-byte End System Identifier plus 1 byte Selector
Correct:D
5.To eliminate the need for adjacent routers on broadcast networks to form n(n-1)/2 adjacencies, IS-IS defines a pseudonode or Designated Intermediate System, DIS. All router on the broadcast medium form an adjacency with the DIS. The Backup DIS is called:
A.Redundant DIS
B.BDR
C.There is no concept of a backup DIS in IS-IS
D.Designated Redundant System
Correct:C
6.Cisco/StrataCom (Gang of four) LMI uses what DLCI for messages?
A.0
B.1023
C.It should be configurable, as per the specification.
D.It is negotiated when the ports become active.
Correct:B
7.Click the Exhibit button to view the topology. Using the above diagram, which are valid BGP AS_Path Attributes received at Net1 for a route originating from AS65100? (multiple answer)

A.200 57000 100 65100
B.200 57000 100 100
C.100 57000 200
D.200 57000 100
E.65100 100 57000 200
Correct:A D E
8.The default network clocking source in a BPX network is:
A.The internal oscillator of the lowest-numbered node
B.The internal oscillator of the highest-numbered node
C.Each node's own internal oscillator
D.The clock chip on the network management system
Correct:B
9.When using IS-IS for IP routing, Dual IS-IS defined by RFC 1195, what is true? (multiple answer)
A.It is necessary to configure a NSAP address.
B.It is not possible to perform both IP and CLNS routing wih the same process.
C.IP address and subnet information is carried in the TLV field on the L-1/L-1 LSPs.
D.Dual IS-IS does not support VLSM information.
Correct:A C
10.What is true about the DLCI field in the Frame Relay header?
A.It consists of two portions, source and destination, which map data to a logical channel.
B.It generally has significance only between the local switch and the DTE device.
C.It is an optional field in the ITU-T specification.
D.It is present only in data frames sent through the network.
Correct:B
11.On each LAN segment with multiple bridges running spanning tree, the bridge closest to the:
A.Designated bridge is selected as root bridge
B.Root bridge is selected as designated bridge
C.Root bridge is not selected as designated bridge
D.Designated bridge is not selected as root bridge
Correct:B
12.What best describes ADPCM?
A.It stands for Advanced Duplicate Packet Code Marking.
B.It specifies no transmission of data during silent periods of voice conversation.
C.It allows synchronous data to be carried over voice card technology.
D.It compresses voice from 64K per channel to 32K, 24K, or 16K per channel.
E.It compresses voice from 64k to approximately 8k.
Correct:D
13.What ATM cell header contains a generic flow control (GFC) field?
A.The NNI ATM cell
B.The UNI ATM cell
C.Both UNI and NNI
D.None of the above
Correct:B
14.What is Fast EtherChannel?
A.A feature to bundle multiple Ethernet point-to-point links quickly into one logical high speed link
B.A feature to bundle multiple Fast-Ethernet point-to-point links into one logical high speed link
C.Another name for full-duplex Fast Ethernet
D.Another name for Gigabit Ethernet
E.None of the above
Correct:B
15.While entering commands on a console, the break key is pressed accidentally and the router reboots. What action could disable this problem?
A.In configuration mode, enter disable break .
B.In configuration mode, enter no service break .
C.Change the configuration register.
D.Replace the router - this is an invalid response to pressing the break key when past 60 seconds after boot.
Correct:C
16.A Peer group leader is chosen by:
A.Dynamic process within a peer group
B.All nodes in the peer group
C.The highest node ID as a tiebreaker
D.The lowest node ID as a tiebreaker
E.Selecting the node that is physically connected to a different peer group
Correct:A B C
17.A router is receiving updates for a subnet from different routing protocols. The administrator wishes to take advantage of a path via a route with a less favorable Administrative Distance. What can be done to effect this without losing any of the updates?
A.Configure a static route with an Administrative Distance of 120
B.Use the Router Configuration mode command distance with an appropriate 'weight' for this subnet
C.Create a distribute-list to block this subnet
D.Modify the default-metric weight of the routing protocol offering the more favorable Administrative Distance
Correct:B
18.What is an advantage of cell technology?
A.Cell technology simplifies the hardware/software architecture allowing for faster switching fabrics.
B.Cells have less overhead.
C.Cell technology guarantees end-to-end error control.
D.Cell technology allows faster switching of IP packets.
Correct:A
19.Which are characteristcs of VAD?
A.VAD is used with ADPCM voice connections only.
B.VAD makes voice traffic bursty.
C.VAD will add delay to a voice connection.
D.VAD connections use less bandwidth on the trunks.
Correct:B D
20.In Frame Relay, what devices resend packets that do not transmit correctly?
A.Digital transmission media cabled to monitor ports, as opposed to straight DCE signaling
B.Network end stations
C.Network switches running SNMP management software
D.Special bridging devices within the backbone cloud
Correct:B
21.A network administrator is using debug commands to check the performance of a network. What steps can the administrator take to ensure that the "debug" will not require too much CPU, or at least that she will not have to reboot the router to disable debug? (multiple answer)
A.Make the debug command as specific as possible
B.Use the max-time parameter of the debug command
C.In configuration mode, enter scheduler interval 15
D.Configure a loopback to channel debug traffic
Correct:A C
22.The network should always be timed from:
A.A stratum 1 clock
B.The source with the best stratum rating in the network
C.A circuit with timing provided from the carrier
D.A single source
Correct:B
23.In Frame Relay, the BECN bit is set by:
A.The Frame Relay network, to inform the DTE receiving the frame that congestion was experienced in the path from source to destination
B.The Frame Relay network, in frames traveling in the opposite direction from those frames that encountered congestion
C.The receiving DTE, to inform the Frame Relay network that it is overloaded and that the switch should throttle back
D.The sending DTE, to inform the Frame Relay network that it is overloaded and that the switch should throttle back
E.Any device that uses an extended DLCI address
Correct:B
24.What Q.931 message cannot be received in response to sending a Q.931 SETUP message?
A.Alerting
B.Call Proceeding
C.Connect
D.USER Information
E.Progress
Correct:D
25.Click the Exhibit button to view the routing table. If a router had the three routes listed, which one of the routes would forward a packet destined for 10.1.1.1?

A.10.1.0.0/16 through EIGRP, because EIGRP routes are always preferred over OSPF or static routes.
B.10.1.0.0/16 static, because static routes are always preferred over OSPF or EIGRP routes.
C.10.1.1.0/24 through OSPF because the route with the longest prefix is always chosen.
D.Whichever route appears in the routing table first.
E.The router will load share between the 10.1.0.0/16 route through EIGRP and the 10.1.0.0/16 static route.
Correct:C
26.Typically, if a 1024 byte AAL5 SDU is segmented and sent as an unconforming burst towards the switch configured as PPD, what cell reaches the far end?
A.Only the first cell makes it through.
B.Only the last cell makes it through.
C.All of the cells make it through, but they have the DE bit set.
D.None of the above
Correct:B
27.When using Frame Relay service interworking, what is true when building a connection?
A.One side uses native Frame Relay (IETF) and the far side uses native ATM with SNAP or NLPID encapsulation.
B.Both sides use native Frame Relay.
C.One side expects Frame Relay frames and the other side expects Frame Relay frames segmented into ATM cells (FR-SSCS).
D.There is no such thing as Frame Relay service interworking.
Correct:A
28.What is the Generic Flow Control (GFC) header in an ATM NNI cell is used for?
A.Rate control between the ATM NNI switches
B.Rate control between UNI devices
C.GFC has local significance, only, and the value encoded in the field is not end-to-end.
D.None of the above
Correct:C
29.What is NOT a reason to deploy MPLS?
A.Ubiquitous acceptance and firm standards
B.Traffic engineering capabilities
C.Simplify lookups in software-based routers
D.Potential use in VPN services
Correct:A
30.What is not a PNNI Signaling Message?
A.CONNECT
B.STATUS ENQUIRY
C.CALL PROCEEDING
D.DELETING
E.ALERTING
F.NOTIFY
Correct:D