Deploying Cisco Service Provider Advanced Network Routing v7.0 (642-885)

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Total 131 questions

When implementing Anycast RP, the RPs are also required to establish which kind of peering with each other?

  • A. BGP
  • B. Multiprotocol BGP
  • C. MSDP
  • D. Bidirectional PIM
  • E. PIM SSM

Answer : C

Explanation: ml
Using Anycast RP is an implementation strategy that provides load sharing and redundancy in Protocol Independent Multicast sparse mode (PIM-SM) networks. Anycast
RP allows two or more rendezvous points (RPs) to share the load for source registration and the ability to act as hot backup routers for each other. Multicast Source Discovery
Protocol (MSDP) is the key protocol that makes Anycast RP possible.

Given the IPv6 address of 2001:0DB8::1:800:200E:88AA, what will be its corresponding the solicited-node multicast address?

  • A. FF01::1:200E:88AA
  • B. FF01::1:FF0E:88AA
  • C. FF01:0DB8::1:800:200E:88AA
  • D. FF02::1:FF0E:88AA
  • E. FF02::1:200E:88AA
  • F. FF02:0DB8::1:800:200E:88AA

Answer : D

IPv6 nodes (hosts and routers) are required to join (receive packets destined for) the following multicast groups:
All-nodes multicast group FF02:0:0:0:0:0:0:1 (scope is link-local)
Solicited-node multicast group FF02:0:0:0:0:1:FF00:0000/104 for each of its assigned unicast and anycast addresses
IPv6 routers must also join the all-routers multicast group FF02:0:0:0:0:0:0:2 (scope is link- local).
The solicited-node multicast address is a multicast group that corresponds to an IPv6 unicast or anycast address. IPv6 nodes must join the associated solicited-node multicast group for every unicast and anycast address to which it is assigned. The IPv6 solicited- node multicast address has the prefix FF02:0:0:0:0:1:
FF00:0000/104 concatenated with the 24 low-order bits of a corresponding IPv6 unicast or anycast address (see Figure 2). For example, the solicited-node multicast address corresponding to the IPv6 address 2037::01:800:200E:8C6C is FF02::1:FF0E:8C6C.
Solicited-node addresses are used in neighbor solicitation messages

Which two functions are supported for BGP extension MP-BGP for IP multicasting?
(Choose two.)

  • A. A network can support incongruent unicast and multicast topologies.
  • B. A network can support congruent unicast and multicast topologies.
  • C. MP-BGP is an enhanced BGP that carries routing information for multiple network layer protocols and IP multicast routes.
  • D. MP-BGP carries single sets of routes for unicast routing and multicast routing.
  • E. MP-BGP is useful when a link dedicated to multicast and unicast traffic is desired.

Answer : A,C

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 static route should be tagged as 666 (tag 666)

Answer : A

Which keyword is used in the syntax to refer to Cisco IOS XR address-family groups, session groups, or neighbor groups?

  • A. inherit
  • B. apply
  • C. use
  • D. commit

Answer : C

Which multicast group range is reserved for SSM?

  • A.
  • B.
  • C.
  • D.

Answer : C


PIM-SSM Operations -
PIM in Source Specific Multicast operation uses information found on source addresses for a multicast group provided by receivers and performs source filtering on traffic.
By default, PIM-SSM operates in the multicast group range for IPv4 and ff3x::/32 (where x is any valid scope) in IPv6. To configure these values, use the ssm range command.
If SSM is deployed in a network already configured for PIM-SM, only the last-hop routers must be upgraded with Cisco IOS XR software that supports the SSM feature.
No MSDP SA messages within the SSM range are accepted, generated, or forwarded

Which two specific characteristics categorize traceroute in an IPv6 routing environment?
(Choose two.)

  • A. Traceroute can show the path to reach any destination IPv6 address.
  • B. Traceroute returns an error for a link-local IPv6 address.
  • C. Traceroute is based on ICMPv6 Type 1 (Destination Unreachable) reply packets to determine the network path.
  • D. Traceroute is based on ICMPv6 Type 3 (Time Exceeded) reply packets to determine the network path.
  • E. Traceroute is based on ICMPv6 Type 2 (Packet Too Big) reply packets to determine the network path.
  • F. Traceroute for IPv6 implements a backwards compatibility option to provide a detailed report in environments running dual-stack.

Answer : A,D

Which two options areadvantages of an IPv6 dual-stack implementation in an enterprise environment? (Choose two.)

  • A. simplifies the route redistribution policies complexity
  • B. requires IPv6-to-IPv4 translation on the uplinks to the service providers
  • C. provides built-in support for Kerberos authentication
  • D. does not have to worry about NAT traversal
  • E. supports multicast properly

Answer : D,E

The bsr-border router PIM interface configuration command is used for what purpose?

  • A. To enable the router as the candidate RP
  • B. To enable the router as the candidate BSR
  • C. To enable the router as the BSR mapping agent
  • D. To set up an administrative boundary to prevent BSR messages from being sent out through an interface
  • E. To define a boundary to restrict the RP discovery and announcement messages from being sent outside the PIM-SM domain

Answer : D

Refer to the exhibit.

Which three statements are correct regarding the Cisco IOS-XR configuration? (Choose three.)

  • A. This router, acting as the RP mapping agent, will send RP announcement messages to the group
  • B. This router, acting as the RP mapping agent, will send RP discovery messages to the group
  • C. This router is the RP mapping agent only for the and multicast groups
  • D. This router is a candidate PIM-SM RP for the multicast group
  • E. This router is a candidate PIM-BIDIR RP for the multicast group
  • F. IGMPv3 is enabled on all interfaces
  • G. Other routers will recognize this router as the RP for all multicast groups with this router loopback 0 IP address

Answer : D,E,F

Which of the following can be used by dual-stack service providers supporting IPv4/IPv6 customers with dual-stack hosts using public IPv6 addresses and private IPv4 addresses?

  • A. NAT64
  • B. 6RD
  • C. 6to4 tunnels
  • D. Carrier-grade NAT

Answer : D

Carrier Grade NAT is a large-scale NAT, capable of providing private-IPv4-to-public-IPv4 translation in the order of millions of translations. Carrier Grade NAT can support several hundred thousand subscribers with the bandwidth throughput of at least 10Gb/s full-duplex.
With IPv4 addresses reaching depletion, Carrier Grade NAT is vital in providing private
IPv4 connectivity to the public IPv4 internet. In addition, Carrier Grade NAT is not limited to
IPv4 NAT; it can also translate between IPv4 and IPv6 addresses.

Which multicast routing protocol supports dense mode, sparse mode and bidirectional mode?

  • A. DVMRP
  • B. MOSPF
  • C. PIM
  • D. MP-BGP
  • E. MSDP

Answer : C

An SP core is running PIM on the network. Multicast groups in this networkare in the range. Which commandenables multicast routing operations without using an

  • A. ip pim autorp
  • B. ip pim ssm default
  • C. ip pim bidir-enable
  • D. ip pim register-source

Answer : B

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

Answer : A,C,D,F

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
(*,, uptime 5:29:15, RP is, flags: SC
Incoming interface: Tunnel0, RPF neighbor, Dvmrp
Outgoing interface list:
Ethernet0, Forward/Sparse, 5:29:15/0:02:57
(,, uptime 5:29:15, expires 0:02:59, flags: C
Incoming interface: Tunnel0, RPF neighbor
Outgoing interface list:
Ethernet0, Forward/Sparse, 5:29:15/0:02:57

When enabling interdomain multicast routing, which two statements are correct? (Choose two.)

  • A. Multiprotocol BGP is used instead of PIM SM to build the intradomain and interdomain multicast distribution trees
  • B. Use MSDP to enable the RPs from different domains to exchange information about active multicast sources
  • C. MSDP SA packets are sent between the multiprotocol BGP peers
  • D. Noncongruent unicast and multicast topologies can be supported using multiprotocol BGP

Answer : B,D

MSDP In the PIM-SM model, multicast sources and receivers must register with their local
RP. Actually, the router closest to the sources or receivers registers with the RP, but the key point to note is that the RP knows about all the sources and receivers for any particular group. RPs in other domains have no way of knowing about sources located in other domains. MSDP is an elegant way to solve this problem.
MSDP is a mechanism that allows RPs to share information about active sources. RPs know about the receivers in their local domain. When RPs in remote domains hear about the active sources, they can pass on that information to their local receivers and multicast data can then be forwarded between the domains. A useful feature of MSDP is that it allows each domain to maintain an independent RP that does not rely on other domains, but it does enable RPs to forward traffic between domains. PIM-SM is used to forward the traffic between the multicast domains.
The RP in each domain establishes an MSDP peering session using a TCP connection with the RPs in other domains or with border routers leading to the other domains. When the RP learns about a new multicast source within its own domain (through the normal PIM register mechanism), the RP encapsulates the first data packet in a Source-Active (SA) message and sends the SA to all MSDP peers. The SA is forwarded by each receiving peer using a modified RPF check, until the SA reaches every MSDP router in the interconnected networkstheoretically the entire multicast internet. If the receiving MSDP peer is an RP, and the RP has a (*, G) entry for the group in the SA (there is an interested receiver), the RP creates (S, G) state for the source and joins to the shortest path tree for the source. The encapsulated data is decapsulated and forwarded down the shared tree of that RP. When the packet is received by the last hop router of the receiver, the last hop router also may join the shortest path tree to the source. The MSDP speaker periodically sends SAs that include all sources within the own domain of the RP

Multiprotocol BGP -
Multiprotocol BGP is an enhanced BGP that carries routing information for multiple network layer protocols and IP multicast routes. BGP carries two sets of routes, one set for unicast routing and one set for multicast routing.
The routes associated with multicast routing are used by the Protocol Independent
Multicast (PIM) feature to build data distribution trees.
Multiprotocol BGP is useful when you want a link dedicated to multicast traffic, perhaps to limit which resources are used for which traffic. Multiprotocol BGP allows you to have a unicast routing topology different from a multicast routing topology providing more control over your network and resources.
In BGP, the only way to perform interdomain multicast

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Total 131 questions