Free Cisco 300-440 Exam Dumps September 2026

The commandredistribute ospf 1 match externalis missing on router R2. This command is needed to redistribute only the external OSPF routes into BGP. The external OSPF routes are those that are learned from another routing protocol or redistributed into OSPF. In this case, the 10.0.10.0/24 network is an external OSPF route, as it is redistributed from EIGRP into OSPF on router R1. The other commands are either already present or not relevant for this scenario.Reference:=

Designing and Implementing Cloud Connectivity (ENCC) v1.0, Module 3: Implementing Cloud Connectivity, Lesson 3.1: Implementing IPsec VPN from Cisco IOS XE to AWS, Topic 3.1.2: Configure BGP on the Cisco IOS XE Router

Security for VPNs with IPsec Configuration Guide, Cisco IOS XE, Chapter: Configuring IPsec VPNs with Dynamic Routing Protocols, Section: Configuring BGP over IPsec VPNs

The bgp advertise-best-external command is used to enable the advertisement of the best external path to internal BGP peers. This command is useful when there are multiple exit points from the local AS to other ASes, and the local AS wants to use the closest exit point for each destination. By default, BGP only advertises the best path to its peers, and the best path is usually the one with the lowest IGP metric to the next hop. However, this may not be the optimal path for traffic leaving the local AS, as it may result in suboptimal hot-potato routing or MED oscillations. The bgp advertise-best-external command allows BGP to advertise the best external path, which is the path with the lowest MED among the paths from different neighboring ASes, in addition to the best path. This way, the internal BGP peers can choose the best exit point based on the MED value, rather than the IGP metric. In this scenario, ASBR1 is configured to receive additional paths from ASBR2, which is a route reflector. ASBR2 receives two paths for the same prefix from AS6500, one from ASBR3 and one from ASBR4. ASBR2 selects the best path based on the IGP metric to the next hop, and advertises it to ASBR1. However, this path may not be the best external path, as it may have a higher MED value than the other path. If the connection between ASBR1 and ASBR2 goes down, ASBR1 will not have any backup path to reach AS6500, as it does not know the other path from ASBR4. To prevent this situation, ASBR1 should be configured with the bgp advertise-best-external command, so that it can receive the best external path from ASBR2, along with the best path. This way, ASBR1 will have a backup path to reach AS6500, in case the primary path fails.Reference:=IP Routing: BGP Configuration Guide - BGP Additional Paths ... - Cisco,BGP Additional Paths

Security groups are a feature in AWS that allow you to control the inbound and outbound traffic to your instances. They act as a virtual firewall that can filter the traffic based on the source, destination, protocol, and port. You can assign one or more security groups to your instances, and each security group can have multiple rules. Security groups are stateful, meaning that they automatically allow the response traffic for any allowed inbound traffic, and vice versa. Security groups are essential for securing your nodes in the AWS EKS cluster, as they can prevent unauthorized access to your Mongo Atlas database or other resources. You can also use security groups to isolate your nodes from other instances in the same VPC or subnet, or to allow communication between nodes in different clusters or regions.Reference:=

AWS Security Groups

Security Groups for Your VPC

Security Groups for Your Amazon EC2 Instances

Security Groups for Your Amazon EKS Cluster

BFD (Bidirectional Forwarding Detection) is a protocol that detects failures in the overlay tunnel between Cisco SD-WAN devices. BFD packets are sent and received periodically by each device to check the liveliness and quality of the connection. If a device does not receive a BFD packet from its peer within a specified timeout interval, it considers the peer to be unreachable and reports a BFD down event. This event triggers a control connection state change and a possible route change in the SD-WAN fabric.

In this scenario, the engineer discovers that BFD is flapping on vEdge1, which means that the BFD session between vEdge1 and the remote Edge device is going up and down repeatedly. This indicates a connectivity issue between the two devices, such as network congestion, packet loss, or misconfiguration. The most likely cause of the problem is that the remote Edge device failed to respond BFD keepalives within the timeout interval, which resulted in a BFD timeout event on vEdge1. This event caused vEdge1 to mark the remote Edge device as down and notify the control plane. The control plane then tried to establish a new BFD session with the remote Edge device, which may have succeeded or failed depending on the network condition. This cycle of BFD session creation and deletion caused the BFD flapping on vEdge1.

The other options are less likely to be the cause of the problem. Option A is incorrect because if the remote Edge device BFD was down, vEdge1 would not receive any BFD packets from it and would not flap. Option C is incorrect because if the remote Edge device had a duplicate IP address, vEdge1 would not be able to establish a BFD session with it in the first place. Option D is incorrect because the control plane does not delete the BFD session unless there is a configuration change or a port-hop event on the device.Reference:Bidirectional Forwarding Detection Flap-Reason Definitions on Cisco vEdge Routers,Cisco Catalyst SD-WAN BFD,Cisco SD WAN: BFD (Bidirectional Forwarding Detection)

To send traffic into an IPsec tunnel to the cloud VPN gateway, the engineer must configure two actions:

Configure access lists that match the interesting user traffic. This is the traffic that needs to be encrypted and sent over the IPsec tunnel. The access lists are applied to the crypto map that defines the IPsec parameters for the tunnel.

Configure policy-based routing (PBR). This is a technique that allows the engineer to override the routing table and forward packets based on a defined policy. PBR can be used to send specific traffic to the IPsec tunnel interface, regardless of the destination IP address. This is useful when the cloud VPN gateway has a dynamic IP address or when multiple cloud VPN gateways are available for load balancing or redundancy.Reference:

Designing and Implementing Cloud Connectivity (ENCC) v1.0, Module 3: Implementing Cloud Connectivity, Lesson 3: Implementing IPsec VPNs to the Cloud, Topic: Configuring IPsec VPNs on Cisco IOS XE Routers

Security for VPNs with IPsec Configuration Guide, Cisco IOS XE, Chapter: Configuring IPsec VPNs, Topic: Configuring Crypto Maps

[Cisco IOS XE Gibraltar 16.12.x Feature Guide], Chapter: Policy-Based Routing, Topic: Policy-Based Routing Overview

This command redistributes the routes learned from BGP AS100 into OSPF Area 1, which allows router R2 to advertise those routes to router R1 and connect the on-premises network to the cloud provider.The other options are incorrect because they either redistribute the wrong routes or use the wrong syntax5.

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