Cisco 642-885 Online Practice Questions and Exam Preparation

Cisco 642-885 Online Questions & Answers

• Question 121:

  Which of the following is a feature added in IGMPv3?

  A. Support for source filtering
  B. Support for Host Membership Report and a Leave Group message
  C. Uses a new variation of the Host Membership Query called the Group-Specific Host Membership Query
  D. Uses an election process to determine the querying router on the LAN
  E. Uses an election process to determine the designated router on the LAN
  F. IPv6 support
  A. Support for source filtering

• Question 122:

  In secure multicast, which protocol is used to distribute secure keys to a multicast group?

  A. ISAKMP
  B. RSA
  C. IPsec
  D. GDOI
  E. SKIP
  D. GDOI

• Question 123:

  Which IPv6 mechanism occurs between a provider edge router and the customer premises equipment router to allow an ISP to automate the process of assigning a block of IPv6 addresses to a customer for use within the customer network?

  A. Router Advertisement
  B. DHCPv6 Prefix Delegation
  C. DHCPv6 Lite
  D. Stateful DHCPv6
  B. DHCPv6 Prefix Delegation

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  http://www.cisco.com/en/US/tech/tk872/technologies_configuration_example09186a0080b8a11 6.shtml

• Question 124:

  A network engineer is working for an ISP and a current eBGP customer requests to enable the BGP TTL security feature. The engineer sees from the current established BGP session that the eBGP peer is directly connected and the ebgp-multihop feature is already in use with a value of one. Which two actions are needed on the Cisco IOS XR router to accomplish the task? (Choose two.)

  A. Configure the neighbor with the command ttl-security.
  B. Disable the eBGP-multihop feature.
  C. Clear the BGP session for the configuration change to take effect.
  D. Enable the BGP TTL security and the BGP peer resets automatically for the change to take effect.
  E. Configure the neighbor with the command ttl-security 254.
  A. Configure the neighbor with the command ttl-security.
  C. Clear the BGP session for the configuration change to take effect.

• Question 125:

  A service provider requests more details about the recent Inter-AS MPLS VPN Option B configuration that was recently deployed. Consider this configuration:

  router bgp 3717 address-family vpnv4 unicast retain route-target all commit !

  Which option describes why this particular command is needed?

  A. The ASBR can have many working customer VRFs, so this configuration ensures the coexistence of all the route-target extended communities that belong to the all ASBR-terminated customer VRFs.
  B. When implementing the Inter-AS Option B MPLS VPN solution, all the route targets that are transmitted over the Inter-AS links need an ASBR local database to forward the customer traffic correctly.
  C. The Inter-AS Option B design implements VPNv4 communication over the Inter-AS link, hence the requirement for a route-target association for each customer VPN connected across two or more ASs.
  D. In the Inter-AS Option B design, no local VRF is maintained on the ASBR routers, so the default behavior of the operating system is to deny any route-target extended community that is encoded in the incoming iBGP updates. This configuration permits VPNv4 communication by accepting the iBGP updates even if no route targets are configured locally.
  D. In the Inter-AS Option B design, no local VRF is maintained on the ASBR routers, so the default behavior of the operating system is to deny any route-target extended community that is encoded in the incoming iBGP updates. This configuration permits VPNv4 communication by accepting the iBGP updates even if no route targets are configured locally.

• Question 126:

  Refer to the exhibit.

  

  Which option is the function of designing a hub and spoke confederation?

  A. allows transit backbone area 66000 to be a blackhole for non-transit ASs
  B. reduces the iBGP mesh, iBGP mesh will be in sub non-transit ASs
  C. increases eBGP sessions between the confederation sub ASs
  D. allows transit backbone area and non-transit ASs to run the same IGP
  B. reduces the iBGP mesh, iBGP mesh will be in sub non-transit ASs

• Question 127:

  Which command set is used to configure BFD support for a BGP neighbor that is reachable through GigabitEthernet 0/0/0/0 on Cisco IOS XR?

  A. router bgp 300 bfd multiplier 2 bfd minimum-interval 20 neighbor 10.20.20.2 remote-as 200
  B. router bgp 300 bfd multiplier 2 bfd minimum-interval 20 neighbor 10.20.20.2 remote-as 200 bfd fast-detect
  C. bfd echo disable router bgp 300 neighbor 10.20.20.2 remote-as 200
  D. bfd router bgp 300 neighbor 10.20.20.2 remote-as 200
  E. interface Gi0/0/0/0 ipv4 verify unicast source reachable-via rx router bgp 300 bfd multiplier 2 bfd minimum-interval 20 neighbor 10.20.20.2 remote-as 200 bfd fast-detect
  F. interface Gi0/0/0/0 ipv4 verify unicast source reachable-via rx bfd interface Gi0/0/0/0 echo disable router bgp 300 bfd multiplier 2 bfd minimum-interval 20 neighbor 10.20.20.2 remote-as 200
  B. router bgp 300 bfd multiplier 2 bfd minimum-interval 20 neighbor 10.20.20.2 remote-as 200 bfd fast-detect

• Question 128:

  When implementing interdomain multicast routing, which mechanism can be used to advertise multicast sources in one domain to the other domains, allowing the RPs to build interdomain multicast distribution trees?

  A. Multiprotocol BGP
  B. PIM
  C. MSDP
  D. Auto RP
  E. BSR
  F. MLD
  C. MSDP

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  Multicast Source Discovery Protocol

  Multicast Source Discovery Protocol (MSDP) is a mechanism to connect multiple PIM sparse- mode domains.

  MSDP allows multicast sources for a group to be known to all rendezvous point(s) (RPs) in different domains.

  Each PIM-SM domain uses its own RPs and need not depend on RPs in other domains. An RP in a PIM-SM domain has MSDP peering relationships with MSDP

  enabled routers in other domains.

  Each peering relationship occurs over a TCP connection, which is maintained by the underlying routing system.

  MSDP speakers exchange messages called Source Active (SA) messages. When an RP learns about a local active source, typically through a PIM register

  message, the MSDP process encapsulates the register in an SA message and forwards the information to its peers. The message contains the source and group

  information for the multicast flow, as well as any encapsulated data. If a neighboring RP has local joiners for the multicast group, the RP installs the S, G route,

  forwards the encapsulated data contained in the SA message, and sends PIM joins back towards the source. This process describes how a multicast path can be

  built between domains.

• Question 129:

  Which configuration for implementing 6PE on an IS-IS-enabled Cisco IOS XR router is correct?

  A. interface GigabitEthernet0/0/0/0 ipv6 address 2001:DB8:DD11::1/64 router isis ipv6-tun net 49.0000.0000.00010.00 address-family ipv6 unicast single-topology redistribute bgp 200 interface GigabitEthernet0/0/0/0 address-family ipv6 unicast router bgp 200 bgp router-id 209.165.202.129 address-family ipv4 unicast address-family ipv6 unicast redistribute isis ipv6-tun neighbor 209.165.202.130 remote-as 200 address-family ipv4 unicast address-family ipv6 labeled-unicast
  B. interface GigabitEthernet0/0/0/0 ipv6 address 2001:DB8:DD11::1/64 router isis ipv6-tun net 49.0000.0000.00010.00 address-family ipv6 unicast single-topology router bgp 200 bgp router-id 209.165.202.129 address-family ipv4 unicast address-family ipv6 unicast redistribute isis ipv6-tun neighbor 209.165.202.130 remote-as 200 address-family ipv4 unicast address-family ipv6 labeled-unicast
  C. interface GigabitEthernet0/0/0/0 ipv6 address 2001:DB8:DD11::1/64 router isis ipv6-tun net 49.0000.0000.00010.00 address-family ipv6 unicast single-topology interface GigabitEthernet0/0/0/0 address-family ipv6 unicast router bgp 200 bgp router-id 209.165.202.129 address-family ipv4 unicast address-family ipv6 unicast redistribute static neighbor 209.165.202.130 remote-as 200 address-family ipv4 unicast address-family ipv6 labeled-unicast
  D. interface GigabitEthernet0/0/0/0 ipv6 address 2001:DB8:DD11::1/64 router isis ipv6-tun net 49.0000.0000.00010.00 address-family ipv6 unicast single-topology interface GigabitEthernet0/0/0/0 address-family ipv6 unicast router bgp 200 bgp router-id 209.165.202.129 address-family ipv4 unicast address-family ipv6 unicast redistribute connected redistribute isis ipv6-tun neighbor 209.165.202.130 remote-as 200 address-family ipv4 unicast address-family ipv6 labeled-unicast
  E. interface GigabitEthernet0/0/0/0 ipv6 address 2001:DB8:DD11::1/64 router isis ipv6-tun net 49.0000.0000.00010.00 address-family ipv6 unicast single-topology interface GigabitEthernet0/0/0/0 address-family ipv6 unicast router bgp 200 bgp router-id 209.165.202.129 address-family ipv4 unicast address-family ipv6 unicast redistribute connected redistribute isis ipv6-tun neighbor 209.165.202.130 remote-as 200 address-family ipv4 unicast
  D. interface GigabitEthernet0/0/0/0 ipv6 address 2001:DB8:DD11::1/64 router isis ipv6-tun net 49.0000.0000.00010.00 address-family ipv6 unicast single-topology interface GigabitEthernet0/0/0/0 address-family ipv6 unicast router bgp 200 bgp router-id 209.165.202.129 address-family ipv4 unicast address-family ipv6 unicast redistribute connected redistribute isis ipv6-tun neighbor 209.165.202.130 remote-as 200 address-family ipv4 unicast address-family ipv6 labeled-unicast

• Question 130:

  Which two BGP mechanisms are used to prevent routing loops when using a design with redundant route reflectors? (Choose two.)

  A. Cluster-list
  B. AS-Path
  C. Originator ID
  D. Community
  E. Origin
  A. Cluster-list
  C. Originator ID