Deploying Cisco Service Provider Advanced Network Routing
Question No: 51
On the PE, which two statements are correct regarding the(192.168.156.60,126.96.36.199) entry? (Choose two,)
The RPF neighbor points towards the RP
The RPF neighbor is reachable overthe Gi0/0/0/1 interface
The OIL contains the GiO/0/0/0 interface
The IIL is Null
Explanation: #show ip mroute
Question No: 52
Whichtwo attributes does BGP select before MED? (Choose two.)
lowest router ID
lowest neighbor IP
Question No: 53
Which statement is correct regarding MP-BGP?
MP-BGP can indicate whether an advertised prefix (NLRI) is to be used for unicast routing, multicast RPF checks or for both using different SAFIs.
MP-BGP uses a single BGP table to maintain all the unicast prefixes for unicast forwarding and all the unicast prefixes for RPF checks.
MP-BGP can be used to propagate multicast state information, which eliminates the need to use PIM for building the multicast distribution trees.
MP-BGP enables BGP to carry IP multicast routes used by MSDP to build the multicast distribution trees.
Answer: A Explanation:
Protocol Independent Multicast
Protocol Independent Multicast (PIM) is a routing protocol designed to send and receive multicast routing updates. Proper operation of multicast depends on knowing the unicast paths towards a source or an RP. PIM relies on unicast routing protocols to derive this reverse-path forwarding (RPF) information. As the name PIM implies, it functions
independently of the unicast protocols being used. PIM relies on the Routing Information Base (RIB) for RPF information. If the multicast subsequent address family identifier (SAFI) is configured for Border Gateway Protocol (BGP), or if multicast intact is configured, a separate multicast unicast RIB is created and populated with the BGP multicast SAFI routes, the intact information, and any IGP information in the unicast RIB. Otherwise, PIM gets information directly from the unicast SAFI RIB. Both multicast unicast and unicast databases are outside of the scope of PIM.
The Cisco IOS XR implementation of PIM is based on RFC 4601 Protocol Independent Multicast – Sparse
Mode (PIM-SM): Protocol Specification. For more information, see RFC 4601 and the Protocol Independent Multicast (PIM): Motivation and Architecture Internet Engineering Task Force (IETF) Internet draft
Question No: 54
You noticed a recent change to the BGP configuration on a PE router, the bgp scan time has been changed from the default value to 30s. Which three effects will this change have? (Choose three.)
The BGP table will be examined and verified more frequently
The BGP keepalive messages will be sent to the BGP peers at a faster rate
The BGP table will be modified more quickly in the event that a next-hop address becomes unreachable
The CPU load of the router will increase
The minimum time interval between sending EBGP and IBGP routing updates will decrease
The BGP convergence time will increase
Question No: 55
Refer to the exhibit.
Router A and Router B are connected via GigabitEthernet interfaces, but they are unable to form an MSDP neighborship. Which two components must be addressed when fixing the MSDP peering issue? (Choose two.)
An msdp default peer is configured on both routers.
A BGP process on each router is present so that MSDP can peer and carry updates.
The router interfaces are PIM-enabled to transport MSDP updates.
The connect-source attribute is configured with a host route under the MSDP process.
The MSDP peering on both routers specifies an origin ID so that it can peer.
The router A loopback interface configures the correct subnet mask.
Question No: 56
To which three IP multicast groups can a multicast MAC address quot;01-00-5E-4D-62-B1quot; listen? (Choose three.)
Question No: 57
Which type of BGP session behaves like an EBGP session during session establishment but behaves like an IBGP session when propagating routing updates where the local preference, multi-exit discriminator, and next-hop attributes are not changed?
BGP sessions between a route reflector and its clients
BGP sessions between a route reflector and its non-client IBGP peers
BGP sessions between a route reflector and another route reflector
Intra-confederation IBGP sessions
Intra-confederation EBGP sessions
Answer: E Explanation:
BGP Routing Domain Confederation
One way to reduce the iBGP mesh is to divide an autonomous system into multiple subautonomous systems and group them into a single confederation. To the outside world, the confederation looks like a single autonomous system. Each autonomous system is fully meshed within itself and has a few connections to other autonomous systems in the same confederation. Although the peers in different autonomous systems have eBGP sessions, they exchange routing information as if they were iBGP peers. Specifically, the next hop, MED, and local preference information is preserved. This feature allows you to retain a single IGP for all of the autonomous systems.
Question No: 58
When configuring PIM operations, what is the effect of setting the SPT threshold to infinity?
The multicast source to the RP path will never switch over to the shortest path tree
All the PIM routers will have more (S,G) states, thus consuming more router resources
The receivers will be able to immediately switch over to the shortest path tree after receiving the first multicast packets on the shared tree via the RP
The last-hop routers will never switch over to the shortest path tree and will always remain on the shared tree
Question No: 59
Refer to the exhibit.
Which configuration is missing to complete the configuration task of enabling BFD with the 192.168.1.1 EBGP peer?
bfd fast-detect also needs to be enabled globally under router bgp 64500 RP/0/RSP0/CPU0:P1(config-bgp)#bfd fast-detect
bfd fast-detect also needs to be enabled for the address-family under address-family ipv4 unicast
bfd fast-detect also needs to be enabled for the 192.168.1.1 neighbor under neighbor 192.168.1.1
bfd fast-detect also needs to be enabled for the 192.168.1.1 neighbor address-family under neighbor 192.168.1.1 address-family ipv4 unicast
bfd fast-detect also needs to be enabled globally on the router RP/0/RSP0/CPU0:P1(config)#bfd fast-detect
Question No: 60
The IPv6 2002::/16 prefix is used in which kind of implementations?
6 to 4
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