Cisco 642-885 Online Practice Questions and Exam Preparation

Cisco 642-885 Online Questions & Answers

• Question 21:

  With PIM-SM operations, which four pieces of information are maintained in the multicast routing table for each (*,G) or (S,G) entry? (Choose four.)

  A. RPF Neighbor
  B. RP Set
  C. Incoming Interface
  D. OIL
  E. DF priority
  F. PIM SM state flags
  A. RPF Neighbor
  C. Incoming Interface
  D. OIL
  F. PIM SM state flags

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  The following is sample output from the show ip mroute command for a router operating in sparse mode:

  show ip mroute IP Multicast Routing Table Flags: D - Dense, S - Sparse, C - Connected, L - Local, P - Pruned R - RP-bit set, F - Register flag, T - SPT-bit set Timers: Uptime/Expires Interface state: Interface, Next-Hop, State/Mode (*, 224.0.255.3), uptime 5:29:15, RP is 198.92.37.2, flags: SC Incoming interface: Tunnel0, RPF neighbor 10.3.35.1, Dvmrp Outgoing interface list: Ethernet0, Forward/Sparse, 5:29:15/0:02:57 (198.92.46.0/24, 224.0.255.3), uptime 5:29:15, expires 0:02:59, flags: C Incoming interface: Tunnel0, RPF neighbor 10.3.35.1 Outgoing interface list: Ethernet0, Forward/Sparse, 5:29:15/0:02:57

• Question 22:

  Refer to the configuration exhibit, taken from a Cisco IOS-XR router.

  

  Which configuration change is required to properly enable this router as the signaling router for implementing source-based RTBH filtering?

  A. Set community (no-export) in the route policy
  B. Pass in the route policy
  C. Set local-preference 1000 in the route policy
  D. The 192.0.2.1/32 static route should be tagged as 666 (tag 666)
  A. Set community (no-export) in the route policy

• Question 23:

  Which two options are the common methods for implementing Site of Origin on Cisco IOS XE routers for loop avoidance in multihome BGP customers? (Choose two.)

  A. Configure the route-map in command on the CE BGP neighbor.
  B. Configure Site of Origin directly on the CE BGP neighbor command.
  C. Configure site-map on VRF interface and redistribution of iBGP.
  D. Configure site-map on VRF interface and network command.
  E. Configure the route-map out command on the P router.
  A. Configure the route-map in command on the CE BGP neighbor.
  B. Configure Site of Origin directly on the CE BGP neighbor command.

• Question 24:

  Refer to the Cisco IOS configuration exhibit.

  

  Which statement is correct?

  A. This configuration is typically configured on the boundary routers within a PIM SM domain to filter out malicious candidate-RP-announce and candidate-RPdiscovery packets
  B. This configuration is typically configured on the RPs within a PIM-SM domain to restrict the candidate-RP-announce packets
  C. This configuration is typically configured on the mapping agents within a PIM-SM domain to restrict the candidate-RP-discovery packets
  D. This configuration is typically configured on the MSDP peering routers within a PIM-SM domain to filter out malicious MSDP SA packets
  A. This configuration is typically configured on the boundary routers within a PIM SM domain to filter out malicious candidate-RP-announce and candidate-RPdiscovery packets

• Question 25:

  Which difference occurs between intradomain and interdomain routing technology?

  A. PIM is used in intradomain routing technology and uses reverse path forwarding mechanism to implement optimize multicast data forwarding.
  B. MSDP is used in intradomain routing technology to discover the multicast source.
  C. Interdomain routing technology uses MSDP and M-BGP for exchanging multicast routing information.
  D. RP is not needed in intradomain routing technology, but RP is needed in interdomain routing technology to receive multicast traffic.
  A. PIM is used in intradomain routing technology and uses reverse path forwarding mechanism to implement optimize multicast data forwarding.

• Question 26:

  A network engineer must deploy an iBGP-based cloud region configuration by means of templates to reduce the overall BGP CLI required. Which three commands represent a basic configuration for a BGP peer session template on a regular Cisco IOS instance? (Choose three.)

  A. template peer-session session-template-name
  B. remote-as as-number
  C. neighbor-family config template
  D. peer-family config template
  E. as-override
  F. timers keepalive-interval hold-time
  A. template peer-session session-template-name
  B. remote-as as-number
  F. timers keepalive-interval hold-time

• Question 27:

  A CRS router that runs Cisco IOS XR has dual routing processors installed. Which solution should be implemented to prevent OSPF adjacency flapping if the primary routing processor fails?

  A. NSR
  B. OSPF Fast Timers
  C. OSPF RE Sync
  D. router msdp
  E. NSF
  A. NSR

• Question 28:

  Which three methods can be used to reduce the full-mesh IBGP requirement in a service provider core network? (Choose three.)

  A. Implement route reflectors
  B. Enable multi-protocol BGP sessions between all the PE routers
  C. Implement confederations
  D. Implement MPLS (LDP) in the core network on all the PE and P routers
  E. Enable BGP synchronization
  F. Disable the IBGP split-horizon rule
  A. Implement route reflectors
  C. Implement confederations
  D. Implement MPLS (LDP) in the core network on all the PE and P routers

• Question 29:

  On Cisco IOS-XR, which BGP configuration group allows you to define address-family independent commands and address-family dependent commands for each address family?

  A. neighbor-group
  B. session-group
  C. af-group
  D. peer-group
  A. neighbor-group

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  ꞏCommands relating to a peer group found in Cisco IOS Release 12.2 have been removed from Cisco IOS XR software. Instead, the af-group, session-group, and neighbor-group configuration commands are added to support the neighbor in Cisco IOS XR software: The af-group command is used to group address family-specific neighbor commands within an IPv4 or IPv6 address family. Neighbors that have the same address family configuration are able to use the address family group name for their address family-specific configuration. A neighbor inherits the configuration from an address family group by way of the use command. If a neighbor is configured to use an address family group, the neighbor will (by default) inherit the entire configuration from the address family group. However, a neighbor will not inherit all of the configuration from the address family group if items are explicitly configured for the neighbor. The session-group command allows you to create a session group from which neighbors can inherit address family-independent configuration. A neighbor inherits the configuration from a session group by way of the use command. If a neighbor is configured to use a session group, the neighbor (by default) inherits the session group's entire configuration. A neighbor does not inherit all the configuration from a session group if a configuration is done directly on that neighbor. The neighbor-group command helps you apply the same configuration to one or more neighbors. Neighbor groups can include session groups and address family groups. This additional flexibility can create a complete configuration for a neighbor. Once a neighbor group is configured, each neighbor can inherit the configuration through the use command. If a neighbor is configured to use a neighbor group, the neighbor (by default) inherits the neighbor group's entire BGP configuration. However, a neighbor will not inherit all of the configuration from the neighbor group if items are explicitly configured for the neighbor. In addition, some part of the neighbor group's configuration could be hidden if a session group or address family group was also being used

• Question 30:

  The 224.192.16.1 multicast IP address maps to which multicast MAC address?

  A. 01-00-5E-C0-10-01
  B. 01-00-5E-40-10-01
  C. 01-00-5E-00-10-01
  D. 01-00-5E-C0-16-01
  B. 01-00-5E-40-10-01

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  Least significant 23 bits of IP address and pre-pend 01-00-5E

  224 ignore 192 less 128 becomes 64 = 40 16 = 10 1 = 01 01-00-5E-40-10-01