Fravo.com Certification Made Easy MCSE, CCNA, CCNP, OCP, CIW, JAVA, Sun Solaris, Checkpoint World No1 Cert Guides info@Fravo.com Building Cisco Multilayer Switched Networks (BCMSN) Exam 642-811 Edition 2.0 © Copyrights 1998-2005 Fravo Technologies. All Rights Reserved. 642-811 http://www.fravo.com 1 Congratulations!! You have purchased a Fravo Technologies. Study Guide. This study guide is a complete collection of questions and answers that have been developed by our professional & certified team. You must study the contents of this guide properly in order to prepare for the actual certification test. The average time that we would suggest you for studying this study guide is approximately 15 to 20 hours and you will surely pass your exam. We guarantee it! GOOD LUCK! 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Which feature will put a switch port into the error-disabled state upon receipt of Spanning Tree data messages, requiring a network administrator to manually put the port back in service? A. Loop Guard B. Port Fast C. BDPU Guard D. Root Guard E. BDPU Filtering Answer: C Explanation: Understanding BPDU Guard The BPDU guard feature can be globally enabled on the switch or can be enabled per interface, but the feature operates with some differences. At the global level, you can enable BPDU guard on Port Fast-enabled ports by using the spanning- tree portfast bpduguard default global configuration command. Spanning tree shuts down ports that are in a Port Fast-operational state. In a valid configuration, Port Fast-enabled ports do not receive BPDUs. Receiving a BPDU on a Port Fast-enabled port signals an invalid configuration, such as the connection of an unauthorized device, and the BPDU guard feature puts the port in the error-disabled state. Reference: http://www.cisco.com/en/US/products/hw/switches/ps5206/products_configuration_guide_chapter 09186a008017ff97.html Q2. Which method of Layer 3 switching uses a forwarding information base (FIB)? A. Route caching B. Flow-based switching C. Demand-based switching D. Topology-based switching Answer: A Explanation: Cisco Express Forwarding reindexes the routing table into a new table called a Forward Information Base (FIB). The FIN is an entry-for-entry match of the routing table that has been reindexed via a binary search algorithm called a Patricia Tree. Reference: Building Cisco Multilayer Switched Networks (Ciscopress) page 412 Q3. Which are two closely related standards specifically designed for data transmission over fiber optic networks? (Choose two.) A. FDDI B. SONET C. SDH D. DSL E. ATM 642-811 http://www.fravo.com 3 Answer: B, E Explanation: Synchronous Digital Hierarchy. The European standard that defines a rate and format for transmission of optical signals over fiber using ATM and SONET. In contrast to PDH, SDH provides for a synchronous multiplexing scheme. Reference: http://www.cisco.com/en/US/products/hw/optical/ps2011/prod_technical_reference09186a00800a 8655.html#998751 Q4. Access Control List (ACL) processing in some Cisco switches is done in hardware. What two actions will take place when the hardware reaches capacity to store ACLs? (Choose two.) A. Performance is increased. B. Performance is decreased. C. Packets are dropped. D. Packet filtering will be accomplished. Answer: B, D Explanation: Determining if the ACL Configuration Fits in Hardware: As previously stated, ACL processing in the Catalyst 3550 switch is mostly accomplished in hardware. However, if the hardware reaches its capacity to store ACL configurations, the switch software attempts to fit a simpler configuration into the hardware. This simpler configuration does not do all the filtering that has been configured, but instead sends some or all packets to the CPU to be filtered by software. In this way, all configured filtering will be accomplished, but performance is greatly decreased when the filtering is done in software. Reference: http://www.cisco.com/en/US/products/hw/switches/ps646/products_configuration_guide_chapter0 9186a008007e701.html Q5. Which well-defined routing protocol would a network administrator configure on multicast routes when member routes are widely dispersed? A. Distance Vector Multicast Routing Protocol (DVMRP) B. Protocol Independent Multicast Dense Mode (PIM-DM) C. Multicast Open Shortest Path First (MOSPF) D. Protocol Independent Multicast Sparse Mode (PIM-SM) E. Core-Based Trees (CBT) Answer: D Explanation: Multicast routing protocols fall into two categories: Dense-mode (DM) and Sparse- mode (SM). DM protocols assume that almost all routers in the network will need to distribute multicast traffic for each multicast group (for example, almost all hosts on the network belong to each multicast group). Accordingly, DM protocols build distribution trees by initially flooding the 642-811 http://www.fravo.com 4 entire network and then pruning back the small number of paths without receivers. SM protocols assume that relatively few routers in the network will be involved in each multicast. The hosts belonging to the group are widely dispersed, as might be the case for most multicasts in the Internet. Therefore, SM protocols begin with an empty distribution tree and add branches only as the result of explicit requests to join the distribution. Reference: http://www.cisco.com/en/US/tech/tk828/tk363/technologies_white_paper09186a0080092942.sht ml Q6. Drag and drop the type of flow mask used with Multiplayer Switching (MLS) in the options column to the statement that defines its character in the target column. Answer: Destination-IP - Used when no access list are configured Source-Destination–IP - Used when standard access list is configured IP-Flow - Used when extended access list is configured Explanation: Flow Mask: • Destination-IP: This mode is used if no access list are configured on any of the MLS router interfaces. • Source-Destination–IP: This mode is used if there is a standard access list on any of the MLS interfaces. • IP-Flow: This mode is used if there is an extended access list on any MLS interfaces. Reference: Building Cisco Multilayer Switched Networks (Ciscopress) page 234-235 Q7. Which QoS technique avoids the problems that occur when tail drops is used as the congestion avoidance mechanism on the router? 642-811 http://www.fravo.com 5 A. RSVP B. WRED C. CAR D. CBWFQ Answer: B Explanation: With class-based QoS queuing, you can create up to 64 classes for an interface. (Unlike WFQ, queues are not automatically based on the packet's ToS value.) Class-based QoS queuing also lets you control the drop mechanism used when congestion occurs on the interface. You can use WRED for the drop mechanism, and configure the WRED queues, to ensure that high- priority packets within a class are given the appropriate weight. If you use tail drop, all packets within a class are treated equally, even if the ToS values are not equal. Reference: http://www.cisco.com/en/US/products/sw/cscowork/ps2064/products_user_guide_chapter09186a0 0800e0a04.html Q8. Which technology manages multicast traffic at Layer 2 by configuring Layer 2 LAN interfaces dynamically to forward multicast only to those interfaces that want to receive it? A. IGMP B. IGMP snooping C. PIM-DIM D. DVMRP E. MOSPF Answer: B Explanation: Understanding IGMP Snooping In subnets where you have configured either IGMP (see "Configuring IP Multicast Layer 3 Switching") or the IGMP querier (see the "Enabling the IGMP Querier" section), IGMP snooping manages multicast traffic at Layer 2 by configuring Layer 2 LAN interfaces dynamically to forward multicast traffic only to those interfaces that want to receive it. Reference: http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_guide_chapter0 9186a00800f4ff2.html Q9. Exhibit: 642-811 http://www.fravo.com 6 Use the following information from switch SwitchA: Port Mode Encapsulation Status Native VLAN fa0/1 desirable n-802.1q trunking 5 Port VLANs is allowed on trunk fa0/1 1-100, 102-1005 Port VLANs is owned and active in management domain fa0/1 1-6. 8-100, 102-15, 197-999, 1002-1005 Port VLANs in spanning tree forwarding state and not pruned fa0/1 1-6, 8-100, 102-105, 108-999, 1002-1005 The network operations center has received a call stating that users in VLAN 107 are unable to access resources through Router Router1. From this information contained in the graphic, what is the cause of this problem? A. VLAN 107 does not exist on switch SwitchA. B. VTP is pruning VLAN 107. 642-811 http://www.fravo.com 7 C. VLAN 107 is not configured on the trunk. D. Spanning tree is not enabled on VLAN 107. Answer: D Q10. Which two table types are CEF components? (Choose two.) A. Forwarding information base B. Adjacency tables C. Neighbor tables D. Caching tables E. Route tables Answer: A, B Explanation: There are two Cisco Express Forwarding components: • Forwarding Information Base • Adjacency table Reference: Building Cisco Multilayer Switched Networks (Ciscopress) page 412 Q11. What is a characteristic of a VLAN map that does not contain a match clause? A. Implicit deny feature at end of list. B. Implicit forward feature at end of list. C. Can only be implemented by the input direction within the VLAN. D. Can only be implemented by the output direction within the VLAN. Answer: A Explanation: Each VLAN access map can consist of one or more map sequences, each sequence with a match clause and an action clause. The match clause specifies IP, IPX, or MAC ACLs for traffic filtering and the action clause specifies the action to be taken when a match occurs. When a flow matches a permit ACL entry the associated action is taken and the flow is not checked against the remaining sequences. When a flow matches a deny ACL entry, it will be checked against the next ACL in the same sequence or the next sequence. If a flow does not match any ACL entry and at least one ACL is configured for that packet type, the packet is denied. Reference: http://www.cisco.com/en/US/products/hw/switches/ps700/products_configuration_guide_chapter0 9186a008007f4d4.html Q12. As a design rule, what is the maximum time that should be allowed for a voice packet to cross a network? A. 60 milliseconds B. 120 milliseconds C. 150 milliseconds 642-811 http://www.fravo.com 8 D. 210 milliseconds Answer: C Explanation: Delay is the time it takes for VoIP packets to travel between two endpoints and you should design networks to minimize this delay. However, because of the speed of network links and the processing power of intermediate devices, some delay is expected. The human ear normally accepts up to about 150 milliseconds (ms) of delay without noticing problems (the ITU's G.114 standard recommends no more than 150 ms of one-way delay). Reference: http://www.cisco.com/en/US/products/sw/iosswrel/ps5014/products_feature_guide09186a008008 80e7.html Q13. What information do CGMP-enabled switches and routers exchange using the CGMP protocol? A. CAM table changes. B. Summarized IGMP information. C. Multicast join and leave events. D. Multicast group to port assignments. Answer: C Explanation: CGMP is based on a client/server model. The router is considered a CGMP server, with the switch taking on the client role. The basis of CGMP is that the IP multicast router sees all ICMP packets and therefore can inform the switch when specific hosts join or leave multicast groups. The switch then uses this information to construct a forwarding table. Reference: Building Cisco Multilayer Switched Networks (Ciscopress) page 306 Q14. TACACS+ uses which of the following protocols to communicate? A. UDP B. CDP C. TCP D. DES Answer: C Explanation: RADIUS uses UDP while TACACS+ uses TCP. TCP offers several advantages over UDP. TCP offers a connection-oriented transport, while UDP offers best-effort delivery. RADIUS requires additional programmable variables such as re-transmit attempts and time-outs to compensate for best-effort transport, but it lacks the level of built-in support that a TCP transport offers. Reference: http://www.cisco.com/en/US/tech/tk583/tk547/technologies_tech_note09186a0080094e99.shtml 642-811 http://www.fravo.com 9 Q15. What are three possible router states of HSRP routers on an LAN? (Choose three.) A. Standby B. Established C. Active D. Idle E. Backup F. Init Answer: A, C, F Explanation: Using HSRP, a set of routers works in concert to present the illusion of a single virtual router to the hosts on the LAN. This set is known as an HSRP group or a standby group. A single router elected from the group is responsible for forwarding the packets that hosts send to the virtual router. This router is known as the Active router. Another router is elected as the Standby router. In the event that the Active router fails, the Standby assumes the packet-forwarding duties of the Active router. Although an arbitrary number of routers may run HSRP, only the Active router forwards the packets sent to the virtual router. Reference: http://www.cisco.com/en/US/tech/tk648/tk362/technologies_tech_note09186a0080094a91.shtml Q16. A customer’s requirement states that they only need to carry VLANs 1,2,10,20 on a trunk. VLANs 1,2,3,4,10,20,50 are currently active in the network. Which two of the following commands can be used to accomplish this requirement? (Choose two.) A. switchport trunk allowed vlan add 1,2,10,20 B. switchport trunk disallowed vlan add 3,4,50 C. switchport trunk disallowed vlan remove 3,4,50 D. switchport trunk allowed vlan remove 3,4,50 E. switchport trunk allowed vlan except 1,2,10,20 F. switchport trunk allowed vlan except 3,4,50 Answer: A, D Explanation: switchport trunk allowed vlan vlan_list The vlan_list format is all | none | [add | remove | except] vlan_atom[,vlan_atom .], where: • all specifies all VLANs from 1 to 4094. This keyword is not supported on commands that do not permit all VLANs in the list to be set at the same time. • none indicates an empty list. This keyword is not supported on commands that require certain VLANs to be set or at least one VLAN to be set. • add adds the defined list of VLANs to those currently set, instead of replacing the list. • remove removes the defined list of VLANs from those currently set, instead of replacing the list. • except lists the VLANs that should be calculated by inverting the defined list of VLANs. • vlan_atom is either a single VLAN number from 1 to 4094 or a continuous range of VLANs described by two VLAN numbers, the lesser one first, separated by a hyphen. [...]... configuration The switch also requires that only the 15 http://www fravo. com 642-811 management VLAN (VLAN1) have access to the switch via Telnet The management VLAN1 has already been configured Management VLAN IP address: 192.168.54.12/24 The passwords to be set are listed below Console: cisco Privilege EXEC: cisco3 3 VTY sessions: cisco6 6 To configure the switch click on the host icon that is connected... over trunk links • Configuring hello message timers • HSRP interface tracking • Displaying the status of HSRP 17 http://www fravo. com 642-811 Reference: Building Cisco Multilayer Switched Networks (Ciscopress) page 272 Q35 What command is used to create a traffic policy on a Cisco IOS-based switch? A route-map B traffic -list C policy-map D policy-list Answer: C Explanation: The policy-map command... to Cisco s modular three-tier (Access/Distribution/Core) design philosophy The testing demonstrated the following high availability and resilience features of Catalyst switches: • per-VLAN Spanning Tree (PVST) using Cisco s InterSwitch Link (ISL) and 802.1Q VLAN Trunking • Cisco Spanning Tree Enhancements, including UplinkFast and PortFast • Cisco Hot Standby Router Protocol (HSRP) and HSRP Track • Cisco. .. virtual LANs (VLANs) within the switched network Reference: Building Cisco Multilayer Switched Networks (Ciscopress) page 8 28 http://www fravo. com 642-811 Q56 What is the purpose of MST as specified by the IEEE 802.1s standard? A It B It C It D It runs a separate instance of STP for each VLAN is the spanning-tree implementation used by non -Cisco 892.1Q switches allows a VLAN bridge to use multiple spanning... main criteria for access devices is to provide this functionality with low-cost, high port density devices 29 http://www fravo. com 642-811 Reference: Building Cisco Multilayer Switched Networks (Ciscopress) page 21 Q58 Which three elements represent intelligent network services in Cisco s Architecture for Voice, Video and Integrated Data (AVVID)? (Choose three.) A Quality of Service (QoS) B AVVID foundation... learns for a period of time called the fwd delay (forward delay) Reference: Building Cisco Multilayer Switched Networks (Ciscopress) page 139 Q60 What describes hardware-based PDU header rewriting and forwarding based on information specific to one or more OSI layers? A Cisco express routing 30 http://www fravo. com 642-811 B Router express forwarding C Multiplayer switching D Multilayer routing Answer:... reports the lowest path cost is chosen to forward Reference: Building Cisco Multilayer Switched Networks (Ciscopress) page 155 Q21 Which process plays a major role in the creation of the CEF adjacency table? A B C D Address Resolution Protocol (ARP) PDU header rewrite NetFlow switching Hello packet exchange Answer: A 11 http://www fravo. com 642-811 Explanation: The next step in processing a packet in a Layer... to disabled 20 seconds 15 seconds 15 seconds in the event of failure Blocking to forwarding state 50 seconds Reference: Building Cisco Multilayer Switched Networks (Ciscopress) page 141 Q45 Match the Multilayer Switching term to the correct definition 23 http://www fravo. com 642-811 Answer: Explanation: MLS components: • Multilayer Switching Engine (MLS-SE) – The switching entity that handles the function... Vector Multicast Routing Protocol (DVMRP) • Multicast Open Shortest Path First (MOSPF) • Protocol-Independent Multicast Dense Mode (PIM DM) Reference: Building Cisco Multilayer Switched Networks (Ciscopress) page 313 13 http://www fravo. com 642-811 Q27 Which three of the following passwords require encryption with the service passwordencryption command to avoid transmission in clear text? (Choose three)... Reference: Building Cisco Multilayer Switched Networks (Ciscopress) page 93 Q52 What is the recommended relationship of VLANs to IP subnets? A One-to-one B One-to-many C Many-to-one D VLANs are mapped to MAC addresses Answer: A Explanation: Cisco systems recommend a one-to-one correspondence between VLANs and IP subnets, there can be no more than 254 devices in on VLAN Reference: Building Cisco Multilayer . 1-6. 8- 100 , 1 02 - 15, 197-999, 10 02- 100 5 Port VLANs in spanning tree forwarding state and not pruned fa0/1 1-6, 8- 100 , 1 02 - 105 , 108 -999, 10 02- 100 5 The network. Reference: Building Cisco Multilayer Switched Networks (Ciscopress) page 4 12 Q 22. In the hardware address 00 00. 0c07.ac0a what does 07 .ac represent? A.