Free Cisco 350-501 Practice Exam with Questions & Answers | Set: 13

The configuration shown in the exhibit is used to disable IP directed-broadcasts on a specific interface of a network device. This is typically done to mitigate smurf attacks, which involve sending a large amount of ICMP echo (ping) traffic to IP broadcast addresses, all having a spoofed source address of the victim’s IP. By disabling IP directed-broadcasts, the network device will not forward packets that are sent to broadcast addresses, thus mitigating this type of DDoS attack. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Module on Security in the Service Provider Network

 To achieve this, we need to apply an access control list (ACL) on PE-R9 that permits SSH traffic from the management network 192.168.0.0/16 while denying other traffic. The correct ACL configuration is as follows:

access-list 100 permit tcp 192.168.0.0 0.0.255.255 any eq 22

access-list 100 deny ip any any

• The first line permits TCP traffic from the management network to any destination with destination port 22 (SSH).
• The second line denies all other IP traffic.

References:

• Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) v1.0 course materials.
• Cisco Learning Network: SPCOR Training Videos
• Cisco Learning Network: Service Provider Training

When creating new Cisco MPLS TE tunnels, the headend router sends a Path message to reserve bandwidth on the path to the tunnel’s tailend router. The Path message is part of the RSVP (Resource Reservation Protocol) used in signaling and establishing MPLS TE tunnels. It carries information about the requested resources and desired parameters for the tunnel123. References: Configuring MPLS TE RSVP, MPLS TE RSVP-TE, MPLS TE Theory.

 ISP delegation to PCE servers involves assigning specific tasks or roles to different PCE servers within a network. Option A refers to adding a new PCE server with lower precedence than the primary PCE, which means introducing an additional server that has less priority in task execution compared to the existing primary one. Option B involves changing the precedence of any of the PCE servers, indicating a modification in their hierarchical order or priority for task execution. References := Cisco Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR)

 The configuration shown in the exhibit indicates a BGP FlowSpec policy that is configured locally on CSR1. This policy is designed to drop all traffic destined for TCP ports 80 and 443 for the IP address 10.6.5.0/24. The traffic rate is displayed as 0 bps, which suggests that the policy is not currently dropping any traffic. However, the matched and dropped statistics indicate that the policy has been active in the past, as it has matched and dropped packets.

References: This explanation is based on the principles of BGP FlowSpec configuration and operation as outlined in the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) study materials. 

R1

router ospf 10

redistribute static

int et0/0

ip ospf hello-interval 5

ip ospf dead-interval 10

ip ospf cost 15

ip ospf 10 area 0

copy run start

R2

router ospf 10

redistribute static

int et0/0

ip ospf hello-interval 5

ip ospf dead-interval 10

ip ospf cost 15

ip ospf 10 area 0

copy run start

The OSPF neighbor relationship is not establishing due to a mismatch in MTU (Maximum Transmission Unit) settings on the interfaces of PE-A and PE-B routers. On PE-A, there is no MTU configuration under the interface FastEthernet0/0, which means it is using the default MTU setting. However, on PE-B, the MTU is explicitly set to 1400 bytes with “ip mtu 1400” command under interface FastEthernet0/0. OSPF requires that both ends of a point-to-point link have matching MTU sizes to form a neighbor relationship; otherwise, OSPF adjacency will not be established.

References:

• Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco SPCOR Resources