ActualTests.Cisco.640-802.Exam.Q.and.A.08.15.08-DDU (1130589), страница 27
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These are not valid options in a Cisco switch.C. ISL is a Cisco proprietary method for setting up trunks, and will only work betweenCisco switches.QUESTION 219:A new switch is being installed in the Certkiller network and you have been assignedthe task of connecting it to an existing switch. In doing this, you want to set up theVLAN Trunking Protocol so that VLAN information can be passed between theswitches. Which of the following must you do to accomplish this? (Choose all thatapply).A. You must set each end of the trunk line to IEEE 802.1e encapsulation.B.
You must set the same VTP management domain name on both switches.C. You must set all ports on the two switches as access ports.D. You must configure one of the switches as a VTP server.E. You must use a rollover cable to connect the two switches.Answer: B, DActualtests.com - The Power of Knowing640-802Explanation:The following describes what is needed in order to correctly set up VTP:Incorrect Answers:A. The encapsulation can be either ISL or 802.1Q, and need to match at each end of thetrunk.C. Ports must only be assigned to VLANS.
Once that is done and the trunk is up andrunning, the VLAN information will be passed between the switches.E. A regular CAT5 cable is used to connect the switches, assuming 10/100 Ethernet isused.QUESTION 220:A new Certkiller switch is installed into an existing LAN and a new VTP trunk is setup with an existing switch.
Which VLANs will be allowed on this new trunk?A. All defined VLANs are allowed on the trunk by default.B. Each VLAN, or VLAN range, that is specified with the switchport mode command.C. Each VLAN, or VLAN range, that is specified with the vtp domain command.D. Each VLAN, or VLAN range, that is specified with the vlan database command.E. None of the aboveAnswer: AExplanation:The question does not state that there are multiple VTP Domains meaning that all definedVLANs are allowed on the trunk until a vtp domain command is issued.QUESTION 221:You need to decide on which trunking method to implement in the Certkillernetwork.
What is a characteristic of ISL and 802.1q frame tagging in a switchedActualtests.com - The Power of Knowing640-802LAN environment?A. They are used to find the best path through a network.B. They allow the exchange of filtering tables.C. They specify different implementations of the Spanning-Tree Protocol.D. They allow the exchange of routing tablesE.
They provide inter-switch VLAN communication.Answer: EExplanation: A trunk link is the other type of Layer 2 port supported on Ciscoswitches. When a trunk port is configured, it begins marking frames as theyexit the port to indicate which VLAN each frame is associated with. Thetrunk port can also read the markings, called tags, as they enter the trunkport. This enables the switch to send a frame only to the ports for thegiven VLAN associated with the incoming frame.The main purpose of trunking is to carry traffic between switches andmaintain the VLAN information.
Unlike an access link, the trunk link doesnot belong to a single VLAN but instead can carry traffic from several VLANsover a point-to-point link between two devices that understand the protocol.Two forms of trunking are used for Cisco switches on Ethernet networks:An IEEE industry standard called IEEE 802.1Q. This is a frame-taggingmechanism that adds a VLAN identifier to the frame by inserting a tag atLayer 2.Another form of trunking on Cisco switches is called Inter-Switch Link(ISL), which is a Cisco proprietary trunking mechanism.
ISL uses a frameencapsulation method that adds a header to identify the VLAN.Incorrect Answers:A, D. These are the functions of routers, not switches.B. Filtering tables can be used on certain Catalyst switches via the use of VLAN accesscontrol lists, but this information is never shared between switches.C. A separate STP instance is created for each VLAN, but the STP implementationremains the same.QUESTION 222:Which one of the following protocols allows the information about the configurationof a new VLAN to be distributed across entire switched network?A.
STPB. VTPC. EIGRPD. SNMPE. CDPF. None of the aboveActualtests.com - The Power of Knowing640-802Answer: BExplanation:Sybex CCNA Study Guide 4th Edition states on page 359:"The basic goals of VLAN Trunking Protocol (VTP) are to manage all configuredVLANs across a switched internetwork and to maintain consistency throughout thatnetwork.
VTP allows an administrator to add, delete, and rename VLANs-informationthat is then propagated to all other switches in the VTP domain."Incorrect Answers:A. STP is the Spanning Tree Protocol, used to prevent bridging loops in a LAN.C. EIGRP is a routing protocol used to exchange routing information, not VLANinformation.D. SNMP is the Simple Network Management Protocol, used to provide information toremote network management stations.E.
CDP is the Cisco Discovery Protocol, which is used to exchange information betweenCisco devices. It can only be used between Cisco routers and switches..QUESTION 223:Which encapsulation types are configurable on a Cisco switch for a trunk? (Selecttwo answer choices)A. VTPB. ISLC. CDPD. 802.1QE. 802.1pF. LLCG. IETFAnswer: B, DExplanation:Trunks are used to carry traffic belonging to multiple VLANs between devices over thesame link. A device can determine which VLAN the traffic belongs to by its VLANidentifier. The VLAN identifier is a tag that is encapsulated with the data. ISL and 802.1qare two types of encapsulations used to carry data from multiple VLANs over trunk links.ISL is a Cisco proprietary protocol for interconnecting multiple switches and maintainingVLAN information as traffic goes between switches.
ISL provides VLAN trunkingcapabilities while maintaining full wire speed performance on Ethernet links infull-duplex or half-duplex mode. ISL operates in a point-to-point environment and willsupport up to 1000 VLANs. In ISL, the original frame is encapsulated and an additionalActualtests.com - The Power of Knowing640-802header is added before the frame is carried over a trunk link. At the receiving end, theheader is removed and the frame is forwarded to the assigned VLAN. .ISL uses PerVLAN Spanning Tree (PVST) which runs one instance of Spanning Tree Protocol (STP)per VLAN. PVST allows for optimal root switch placement for each VLAN and supportsload balancing of VLANs over multiple trunk links.802.1Q is the IEEE standard for tagging frames on a trunk and supports up to 4096VLANs.
In 802.1Q, the trunking device inserts a four-byte tag into the original frame andre-computes the Frame Check Sequence (FCS) before sending the frame over the trunklink. At the receiving end, the tag is removed and the frame is forwarded to the assignedVLAN. 802.1Q does not tag frames on the native VLAN.
It tags all other framestransmitted and received on the trunk. While configuring a 802.1 trunk, you must makesure that the same native VLAN is configured on both sides of the trunk. IEEE 802.1Qdefines a single instance of spanning tree running on the native VLAN for all the VLANsin the network which is called Mono Spanning Tree (MST). This lacks the flexibility andload balancing capability of PVST available with ISL. However, PVST+ offers thecapability to retain multiple Spanning Tree topologies with 802.1Q trunking.QUESTION 224:You need to configure an 802.1Q link on a Certkiller switch. Which commands,when used together, would do this? (Select two answer choices)A.
Switch(vlan)# mode trunkB. Switch(config)# switchport access mode trunkC. Switch(config-if)# switchport mode trunkD. Switch(config-if)# switchport trunk encapsulation dot1qE. Switch(config)# switchport access mode 1F. Switch(vlan)# trunk encapsulation dot1qAnswer: C, DExplanation:Creating this trunk link is a two step process. First you have to set the switchport mode totrunk, and then you configure the encapsulation. The giveaway on this question is thefact that to create a trunk on an interface, you have to be in interface configuration mode.So switchport mode trunk sets the trunk, and switchport trunk encapsulation dot1q setsthe encapsulation.QUESTION 225:Which of the following are VLAN frame encapsulation types that may beconfigured on a Catalyst switch? (Choose two.)A.
VTPActualtests.com - The Power of Knowing640-802B. ISLC. CDPD. 802.1QE. 802.1pF. LLCAnswer: B, DExplanation:The two VLAN trunking encapsulation types are:Inter-Switch Link (ISL): This is proprietary to Cisco switches, and it's used for FastEthernet and Gigabit Ethernet links only. ISL routing can be used on a switch port, routerinterfaces, and server interface cards to trunk a server.
ISL lets you explicitly tag VLANinformation onto an Ethernet frame. This tagging information allows VLANs to bemultiplexed over a trunk link through an external encapsulation method, which allowsthe switch to identify the VLAN membership of a frame over the trunked link.IEEE 802.1Q: Created by the IEEE as a standard method of frame tagging, this actuallyinserts a field into the frame to identify the VLAN.
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