Practice Free 300-440 Designing and Implementing Cloud Connectivity (ENCC) Exam Questions Answers With Explanation

 In the given scenario, an engineer is configuring a site-to-site IPsec VPN connection between an on-premises Cisco IOS XE router and AWS. The correct command to complete the tunnel configuration is “tunnel source 20.20.20.21”. This command specifies the source IP address for the tunnel, which is essential for establishing a secure connection between two endpoints over the internet or another network1. References:

• Configure IOS-XE Site-to-Site VPN Connection to Amazon Web Services - Cisco Community
• [Security for VPNs with IPsec Configuration Guide, Cisco IOS XE Release 3S - Config

The architecture model that establishes internet-based connectivity between on-premises networks and AWS cloud resources is the one that establishes an iPsec VPN tunnel with Internet Key Exchange (IKE) for secure key negotiation and encrypted data transmission. This model is also known as the VPN CloudHub model12. It allows multiple remote sites to connect to the same virtual private gateway in AWS, creating a hub-and-spoke topology1. The VPN CloudHub model provides the following benefits12:

• It enables secure communication between remote sites and AWS over the public internet, using encryption and authentication protocols such as IPsec and IKE.
• It supports dynamic routing protocols such as BGP, which can automatically adjust the routing tables based on the availability and performance of the VPN tunnels.
• It allows for redundancy and load balancing across multiple VPN tunnels, increasing the reliability and throughput of the connectivity.
• It simplifies the management and configuration of the VPN connections, as each remote site only needs to establish one VPN tunnel to the virtual private gateway in AWS, rather than multiple tunnels to different VPCs or regions.

The other options are not correct because they do not establish internet-based connectivity between on-premises networks and AWS cloud resources. Option B relies on AWS Elastic Load Balancing (ELB) for traffic distribution and uses SSL/TLS encryption for secure data transmission. However, ELB is a service that distributes incoming traffic across multiple targets within a VPC, not across different networks3. Option C employs AWS Direct Connect for a dedicated network connection and uses private IP addresses for secure communication. However, AWS Direct Connect is a service that establishes a private connection between on-premises networks and AWS, bypassing the public internet4. Option D uses Amazon CloudFront for caching and distributing content globally and uses HTTPS for secure data transfer. However, Amazon CloudFront is a service that delivers static and dynamic web content to end users, not to on-premises networks5.

References:

• 1: Designing and Implementing Cloud Connectivity (ENCC, Track 1 of 5)
• 2: Cisco ASA Site-to-Site VPN
• 3: What Is Elastic Load Balancing?
• 4: What is AWS Direct Connect?

 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

An identity mismatch occurs when the local and remote identities configured on the IPsec peers do not match. This can prevent the establishment of an IPsec tunnel or cause traffic to be dropped by the IPsec policy. In this case, the network engineer should verify that the local and remote identities configured on the Cisco WAN edge router and the AWS endpoint match the values expected by each peer. The identities can be an IP address, a fully qualified domain name (FQDN), or a distinguished name (DN). The identities are exchanged during the IKE phase 1 negotiation and are used to authenticate the peers. If the identities do not match, the peers will reject the IKE proposal and the IPsec tunnel will not be established or will be torn down. References :=

• Configure IOS-XE Site-to-Site VPN Connection to Amazon Web Services, Topic: Troubleshooting
• Designing and Implementing Cloud Connectivity (ENCC) v1.0, Module 3: Implementing Cloud Connectivity, Lesson 2: Implementing Cisco SD-WAN Cloud OnRamp for IaaS, Topic: Troubleshooting Cisco SD-WAN Cloud OnRamp for IaaS
• Cisco IOS Security Configuration Guide, Release 15M&T, Chapter: Configuring IPsec Network Security, Topic: Configuring IPsec Identity and Peer Addressing

• To configure a custom application with Cisco SD-WAN centralized policy, you need to follow these steps25:

The process of configuring a custom application with a Cisco SD-WAN centralized policy using Cisco vManage involves several steps1.

• Click Configuration, select Policies, and then select Centralized Policy: This is the first step where you navigate to the Policies section in the Configuration menu of Cisco vManage1.
• Click Custom Options, select Centralized Policy, and then select Lists: In this step, you select the Custom Options, then select Centralized Policy, and finally select Lists1.
• Click Custom Applications, and then select New Custom Application: After setting up the Lists, you click on Custom Applications and then select New Custom Application1.
• Enter a name for the application, enter the match criteria, and then click Add: Finally, you enter a name for the application, specify the match criteria, and then click Add to complete the configuration1.

References :=

• Cisco Catalyst SD-WAN Policies Configuration Guide, Cisco IOS XE

The configuration of cloud connectivity with Cisco Umbrella Secure Internet Gateway (SIG) in active/backup mode involves several steps. After configuring the SIG Credentials and SIG Feature Templates, the engineer must:

• Select the SIG provider for the primary tunnel: This is the first step in setting up the active/backup mode. The primary tunnel is the main connection path for the cloud connectivity.
• Add the secondary tunnel: The secondary tunnel serves as a backup in case the primary tunnel fails. It ensures that the cloud connectivity remains uninterrupted even if there are issues with the primary tunnel.
• Create one high-availability pair using primary and secondary tunnels: This step involves pairing the primary and secondary tunnels to create a high-availability pair. Thisensures that the cloud connectivity will switch over to the secondary tunnel seamlessly if the primary tunnel fails.
• Edit the service-side VPN template to inject a service route: The final step involves modifying the VPN template on the service side to include a service route. This ensures that the traffic is correctly routed through the primary or secondary tunnel as needed.

References :=

• Designing and Implementing Cloud Connectivity (ENCC) v1.01
• Learning Plan: Designing and Implementing Cloud Connectivity v1.0 (ENCC 300-440) Exam Prep2
• Configure Umbrella SIG Tunnels for Active/Backup or Active/Active Scenarios - Cisco3