Which two protocols are used by bridges and/or switches to prevent loops in a layer 2 network?（）

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• Which two are characteristics of the IS -IS protocol but not OSPF?（）

  A . forms adjacencies with all neighbors B . supports demand circuit routing C . provides routing support for multiple network layer protocols D . utilizes SPF algorithm E . provides for network scalability by allowing the network to be separated into areas F . three layers of hierarchical routing

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• Which two of these are characteristics of the 802.1Q protocol?（）

  A . it is a layer 2 messaging protocol which maintains vlan configurations across network. B . it includes an 8-bit field which specifies the priority of a frame. C . it is used exclusively for tagging vlan frames and dose not address network reconvergence following switched network topology changes. D . it modifies the 802.3 frame header,and thus requires that the FCS be recomputed. E . it is a trunking protocol capable of carring untagged frames.

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• Which two statements are true about the protocols that are used for transmitting voice traffic？（）

  A . RTP multiplexing is used to keep multiple phone conversations separate B . RTP provides end-to-end delivery services for voice traffic. C . UDP is used to ensure a reliable transmission from sender to receiver. D . RTP is used to provide resource reservation for the voice stream. E . UDP provides multiplexing of multiple phone conversations.

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• Which two design recommendations are most appropriate when OSPF is the data center core routing protocol? （）

  A . Never use passive interfaces. B . Use NSSA areas from the core down. C . Use totally stub areas to stop type 3 LSAs. D . Use the lowest Ethernet interface IP address as the router ID. E . Tune OSPF timers to enable OSPF to achieve quicker convergence.

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• Regarding DHCP (dynamic host configuration protocol), which two of the following choices below are true?（）

  A . The DHCP Discover message uses FF-FF-FF-FF-FF as the Layer 2 destination address. B . The DHCP Discover message uses UDP as the transport layer protocol. C . The DHCP Discover message uses a special Layer 2 multicast address as the destination address. D . The DHCP Discover message uses TCP as the transport layer protocol. E . The DHCP Discover message does not use a Layer 2 destination address. F . The DHCP Discover message does not require a transport layer protocol.

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• Which two Internet Protocol (IP) telephony devices are best categorized as infrastructurecomponents?（）

  A . Call management software B . Media Convergence Servers (MCSs) C . Voice gateways D . IP telephone

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• Which two statements about the IS -IS routing protocol are true?（）

  A . IS - IS is capable of supporting IPv4 and IPv6. B . IS - IS is only capable of supporting IPv4 and CLNS. C . IS - IS routers use ES - IS hellos (ESH) to establish and to maintain neighbor relationships. D . IS - IS routers run the Bellman - Ford algorithm against their LSDBs to pick the best paths. E . Level 1 routers learn about paths within the area of which they are a part. F . Level 2 routers learn about paths both within areas and between areas.

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• Which two of the following are designated fields for MAC tunneling protocol（802.1 ah）？（）

  A . Service Ethertype B . ISL C . PseudoLAN TAG D . 802.1q VLAN TAG E . Control Word F . Tunnel Label

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• Which two statements are true about RPF checks in MSDP（Multicast Source Discovery Protocol）？（）

  A . It prevents message looping，Session Advertisement（SA）messages must be RPF checked B . RPF check should be done against the route to the Rendez-vous Point of the corresponding PIM-SM domain，which originated the SA C . RPF checking Session Advertisement（SA）messages will cause message looping D . RPF check should be done against the route to the source S of the corresponding PIM-SM domai

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• Which two statements are characteristics of a distance vector routing protocol?（）

  A . RIP is an example of distance vector routing protocols. B . Updates are periodic and include the entire routing table. C . Routing updates are sent only after topology changes D . The protocol can be useful in hub-and-spoke and hierarchical networks. E . Convergence is usually faster than with link state protocols F . Each router has its own view of the topology

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• Which two statements are characteristics of a distance vector routing protocol？（）

  A . RIP is an example of distance vector routing protocols. B . Updates are periodic and include the entire routing table. C . Routing updates are sent only after topology changes D . The protocol can be useful in hub-and-spoke and hierarchical networks. E . Convergence is usually faster than with link state protocols F . Each router has its own view of the topology

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• Which two link protocols are used to carry multiple VLANs over a single link?（）

  A . VTP B . 802.1q C . IGP D . ISL E . 802.3u

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• Which two statements are true about Internet Group Management Protocol (IGMP) snooping?（）

  A . IGMP snooping and Cisco Group Membership Protocol (CGMP) can be used simultaneously on a switch. B . IGMP snooping a nd Cisco Group Membership Protocol (CGMP) were developed to help Layer 3 switches make intelligent forwarding decisions on their own. C . IGMP snooping examines IGMP join/leave messages so that multicast traffic is forwarded only to hosts that sent an IG MP message toward the router. D . IGMP snooping is an IP multicast constraining mechanism for Layer 2 switches. E . IGMP snooping is enabled with the ip multicast - routing global configuration command.

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• Which two Internet Protocol (IP) telephony devices are best categorized as infrastructure components? （）

  A . IP telephones B . Voice gateways C . Call management software D . Media Convergence Servers (MCSs)

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• Which two design recommendations are most appropriate when OSPF is the data center core routing protocol？ （）

  A .  Never use passive interfaces. B .  Use NSSA areas from the core down. C .  Use totally stub areas to stop type 3 LSAs. D .  Use the lowest Ethernet interface IP address as the router ID. E .  Tune OSPF timers to enable OSPF to achieve quicker convergence

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• Which two multicast protocol statements are true？ （Choose two.）  （）

  A .  Dense mode multicast requires explicit join messages from their members. B .  Dense mode multicast uses a push model to flood traffic throughout the network and then prunes the  unwanted traffic. C .  Sparse mode multicast uses a pull model to send multicast traffic to where it is requested.   D .  Sparse mode uses reverse path forwarding （RPF） to prune off redundant flows. E .  The primary use of sparse mode multicast is for test labs and router performance testing.

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• Which two values are used by Spanning Tree Protocol to elect a root bridge (Choose two.)（）。

  A . amount of RAM B . bridge priority C . IOS version D . IP address E . MAC address F . speed of the link

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• Which two values are used by Spanning Tree Protocol to elect a root bridge? (Choose two.)（）。

  A . amount of RAM B . bridge priority C . IOS version D . IP address E . MAC address F . speed of the link

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• Which two are NOT characteristics of the OSPF routing protocol?（）

  A . It confines network instability to a single area of network. B . It increases the routing overhead of the network C . It supports VLSM D . It routes between Autonomous Systems. E . It allows extensive control of routing update

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• Which two design recommendations are most appropriate when EIGRP is the data center core routing protocol?（）

  A . Summarize data center subnets. B . Use passive interfaces to ensure appropriate adjacencies. C . Tune the EIGRP timers to enable EIGRP to achieve quicker convergence. D . Adjust the default bandwidth value to ensure proper bandwidth on all links. E . Advertise a default summary route into the data center core from the aggregation layer.

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• Which two design recommendations are most appropriate when EIGRP is the data center corerouting protocol？ （）

  A .  Summarize data center subnets. B .  Use passive interfaces to ensure appropriate adjacencies. C .  Tune the EIGRP timers to enable EIGRP to achieve quicker convergence. D .  Adjust the default bandwidth value to ensure proper bandwidth on all links. E .  Advertise a default summary route into the data center core from the aggregation layer.

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• Which two of these are characteristics of the 802.1Q protocol？（）

  A . it is a layer 2 messaging protocol which maintains vlan configurations across network. B . it includes an 8-bit field which specifies the priority of a frame. C . it is used exclusively for tagging vlan frames and dose not address network reconvergence following switched network topology changes. D . it modifies the 802.3 frame header，and thus requires that the FCS be recomputed. E . it is a trunking protocol capable of carring untagged frames.

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• Which two values are used by Spanning Tree Protocol to elect a root bridge?（）

  A . amount of RAM B . bridge priority C . IOS version D . IP address E . MAC address F . speed of the link

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• Which two primary port authentication protocols are used with VSANs？（）

  A . SPAP B . CHAP C . DHCHAP D . ESP

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