300-440 Dumps With Exact Questions and Answers

Step 1 = Click Configuration, select Templates, and then select Feature Templates. Step 2 = Click Add Template, select the device, and then click Basic Configuration. Step 3 = Shut down the tunnel and then remove the ISAKMP profile. Step 4 = Attach the IKEv2 profile and then run the no shutdown command on the tunnel.

The process of configuring a site-to-site IPsec VPN connection between an on-premises Cisco IOS XE router in Controller mode and AWS, and changing the IKE version from IKEv1 to IKEv2 in Cisco vManage involves several steps123.

• Click Configuration, select Templates, and then select Feature Templates: This is the first step where you navigate to the Templates section in the Configuration menu of Cisco vManage1.
• Click Add Template, select the device, and then click Basic Configuration: In this step, you add a new template for the device and proceed with the basic configuration1.
• Shut down the tunnel and then remove the ISAKMP profile: Before changing the IKE version, you need to shut down the existing tunnel and remove the ISAKMP profile that is configured for IKEv12.
• Attach the IKEv2 profile and then run the no shutdown command on the tunnel: Finally, you attach the newly created IKEv2 profile to the tunnel and bring the tunnel back up2.

References :=

• Configuring Internet Key Exchange Version 2 (IKEv2) - Cisco
• Switch from IKEv1 to IKEv2 on Cisco Routers - Cisco Community
• Configure IOS-XE Site-to-Site VPN Connection to Amazon Web Services - Cisco Community

 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, itconsiders 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. References: Bidirectional Forwarding Detection Flap-Reason Definitions on Cisco vEdge Routers, Cisco Catalyst SD-WAN BFD, Cisco SD WAN: BFD (Bidirectional Forwarding Detection)

 The end-to-end ping between the office user PC and the AWS EC2 instance is not working because either the security group rules for the host VPC are blocking the ICMP traffic or the IPsec SA counters are showing errors or drops. To diagnose the loss of connectivity, the engineer should check both the security group rules and the IPsec SA counters. The network security group rules on the host VNET are not relevant because they apply to Azure, not AWS. The IPsec SA configuration on the Cisco VPN router and the AWS private virtual gateway are not likely to be the cause of the problem because the site-to-site VPN tunnel is already up and the site-to-site routing works correctly. References :=

• Designing and Implementing Cloud Connectivity (ENCC, Track 1 of 5), Module 3: Configuring IPsec VPN from Cisco IOS XE to AWS, Lesson 3: Verify IPsec VPN Connectivity
• Security for VPNs with IPsec Configuration Guide, Cisco IOS XE, Chapter: IPsec VPN Overview, Section: IPsec Security Association
• AWS Documentation, User Guide for AWS VPN, Section: Security Groups for Your VPC