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?
A. The BGP table will be examined and verified more frequently.
B. The minimum time interval between sending EBGP and IBGP routing updates will decrease.
C. The BGP convergence time will increase.
D. The BGP keepalive messages will be sent to the BGP peers at a faster rate.
E. The BGP table will be modified more quickly in the event that a next-hop address becomes unreachable.
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?
router static address-family ipv4 unicast 192.0.2.1/32 Null0 ! route-policy RTBH if tag is 666 then set next-hop 192.0.2.1 endif end-policy ! router bgp 65123 address-family ipv4 unicast redistribute static route-policy RTBH ! !When attacks are detected from 209.165.201.144/28 ! router static address-family ipv4 unicast 209.165.201.144/28 null0 tag 666 !
A. pass in the route policy
B. The 192.0.2.1/32 static route should be tagged as 666 (tag 666)
Which two statements correctly describe the RPF check when a multicast packet arrives at a router?
A. If the packet has arrived on the interface leading back to the destination, the RPF check passes and the packet is forwarded. If the RPF check fails, the packet is dropped.
B. The router looks up the destination address in the unicast routing table to determine if the packet has arrived on the interface that is on the reverse path back to the destination.
C. The router looks up the source address in the unicast routing table to determine if the packet has arrived on the interface that is on the reverse path back to the source.
D. If the packet has arrived on the interface leading back to the source, the RPF check passes and the packet is forwarded. If the RPF check fails, the packet is dropped.
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?
Which two statements regarding Auto RP operations and implementations are correct?
A. A Reverse Path Forwarding check is done on the RP discovery messages
B. Candidate RPs send RP announcements to the 224.0.1.39 multicast group, and the mapping agents send RP discovery messages to the 224.0.1.40 multicast group
C. Every PIM-SM router must be configured with the RP mapping agent IP address
D. Administrative scoping can be configured to limit the scope of the RP announcements
E. Candidate RPs learn the IP address of the mapping agents via periodic RP discovery messages
F. RP discovery messages are flooded hop by hop throughout the network as multicast to the all PIM routers multicast group with a TTL of 1
When configuring PIM operations, what is the effect of setting the SPT threshold to infinity?
A. The multicast source to the RP path will never switch over to the shortest path tree
B. 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
C. All the PIM routers will have more (S, G) states, thus consuming more router resources
D. The last-hop routers will never switch over to the shortest path tree and will always remain on the shared tree
Assume that the R1 router is enabled for PIM-SM and receives a multicast packet sourced from 172.16.1.100, and the R1 router has multicast receivers on the Gi0/1, Gi0/2, Gi0/3 and Gi0/4 interfaces. The multicast packet from the 172.16.1.100 source must arrive on which interface on the R1 router for it to be forwarded out the other interfaces?
R1 routing table:
172.16.1.0/24 via Gi0/1 172.16.2.0/24 via Gi0/2 172.16.3.0/24 via Gi0/3 0.0.0.0/0 via Gi0/4
Refer to the exhibit. Which statement correctly explains the bgp graceful-restart command?
router bgp 65123 bgp graceful-restart ! neighbor-group X graceful-restart
A. This command is used to enable NSR and is entered on the NSR-capable router, and also on any NSR-aware peer
B. This command is only required on the NSF-capable routers to enable BGP graceful restart with the BGP peers
C. This command is only required on the NSR-capable routers to enable BGP graceful restart with the BGP peers
D. This command is used to enable NSF and is entered on the NSF-capable router, and also on any NSF-aware peer
E. This command is only required on the NSF-aware routers to enable BGP graceful restart with the BGP peers
The data-forwarding plane of a router can continue to process and forward packets even if the control plane - which is responsible for determining best paths - fails. Also reduces routing flaps, which stabilizes the network and reduces the consumption of control-plane resources.
A. 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 RP/0/RSP0/CPU0:P1(config-bgp-nbr-af)#bfd fast-detect
B. bfd fast-detect also needs to be enabled for the address-family under address-family ipv4 unicast RP/0/RSP0/CPU0:P1(config-bgp-af)#bfd fast-detect
C. bfd fast-detect also needs to be enabled for the 192.168.1.1 neighbor under neighbor 192.168.1.1 RP/0/RSP0/CPU0:P1(config-bgp-nbr)#bfd fast-detect
D. bfd fast-detect also needs to be enabled globally on the router RP/0/RSP0/CPU0:P1(config)#bfd fast-detect
E. bfd fast-detect also needs to be enabled globally under router bgp 64500 RP/0/RSP0/CPU0:P1(config-bgp)#bfd fast-detect
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?
Refer to the Cisco IOS-XR configuration exhibit. The Cisco IOS-XR router is unable to establish any PIM neighbor relationships. What is wrong with the configuration?
When a BGP route reflector receives an IBGP update from a non-client IBGP peer, the route reflector will then forward the IBGP updates to which other router(s)?
A. To the EBGP peers and other clients and non-clients.