Step 1 = Create a Customer Gateway (CGW) in AWS. Step 2 = Create a Virtual Private Gateway (VGW) in AWS. Step 3 = Create a site-to-site VPN connection in AWS. Step 4 = Configure the IOS XE router with the required IPsec VPN parameters and routing settings. Step 5 = Verify and test the VPN connection.

The process of configuring a site-to-site VPN connection between an on-premises Cisco IOS XE router and Amazon Web Services (AWS) involves several steps12.

• Create a Customer Gateway (CGW) in AWS: This is the first step where you define the public IP address of your on-premises Cisco IOS XE router in AWS1.
• Create a Virtual Private Gateway (VGW) in AWS: This involves creating a VGW and attaching it to the VPC in AWS1.
• Create a site-to-site VPN connection in AWS: After setting up the CGW and VGW, you then create a site-to-site VPN connection in AWS. This involves specifying the CGW, VGW, and the static IP prefixes for your on-premises network1.
• Configure the IOS XE router with the required IPsec VPN parameters and routing settings: After the AWS side is set up, you configure the on-premises Cisco IOS XE router with the required IPsec VPN parameters and routing settings2.
• Verify and test the VPN connection: Finally, you verify and test the VPN connection to ensure that it is working correctly12.

References :=

• Configure IOS-XE Site-to-Site VPN Connection to Amazon Web Services - Cisco Community
• SD-WAN Configuration Example: Site-to-site (LAN to LAN) IPSec between vEdge and Cisco IOS - Cisco Community

 Cisco SD-WAN IPsec tunnels are different from native IPsec VPN tunnels in several ways. One of the unique features of Cisco SD-WAN IPsec tunnels is that they support real-time dynamic path selection, which means that they can automatically choose the best path for each application based on the network conditions and policies. This feature improves the performance, reliability, and efficiency of the network traffic. Native IPsec VPN tunnels, on the other hand, do not have this capability and rely on static routing or manual configuration to select the path for each tunnel. This can result in suboptimal performance, increased latency, and higher costs. References := Traditional IPsec Versus Cisco SD-WAN IPsec, SD-WAN vs IPsec VPN’s - What’s the difference?, SD-WAN vs. VPN: How Do They Compare?, Traditional IPSEC Versus SD-WAN IPSEC

 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

Enhanced Policy-Based Routing (ePBR) is used to direct packets that arrive at an interface to a specified next-hop. It is very useful in managing a large number of configured access lists more efficiently. In ePBR, the router drops the traffic packets if the next hop configured in the PBR policy is not reachable. To avoid packet loss in such scenarios, you must configure multiple next hops for each access control entry.

Here are the steps to configure ePBR for IPv4 using Cisco vManage:

• Configure an extended ACL: This step involves defining the network or the host. For example, you can permit IPv4 traffic from any source to specific hosts.
• Configure a class map that matches the ACL: Class maps match the parameters in the ACLs. For instance, you can create a class map of type traffic and match it with the previously created ACL.
• Configure the policy map with the action to set the next hop: Policy maps with ePBR then take detailed actions based on the set statements configured. You can configure an ePBR policy map with the class map and set the next hop.
• Apply the service policy on the interface: Finally, you apply the ePBR policy map to the interface. For example, you can apply the policy map to a GigabitEthernet interface.

References :=

• Implementing Enhanced Policy Based Routing - Cisco
• Cisco Catalyst SD-WAN Policies Configuration Guide, Cisco IOS XE
• How to configure PBR - Cisco Community

The process of configuring a Cisco SD-WAN Cloud Interconnect with Equinix involves several steps.

• Ensure that you have UUIDs for the required number of Cisco SD WAN Virtual Edge instances that you want to deploy as Interconnect Gateways: This is the first step where you ensure that you have the necessary UUIDs for the Cisco SD-WAN Virtual Edge instances that you want to deploy.
• Create the necessary network segments: After ensuring the availability of UUIDs, you create the necessary network segments.
• Attach Cisco SD-WAN Virtual Edge to the Equinix device template: After setting up the network segments, you attach the Cisco SD-WAN Virtual Edge to the Equinix device template.
• Create the Interconnect Gateway at the Equinix location that is closest to your SD-WAN branch location: Finally, you create the Interconnect Gateway at the Equinix location that is closest to your SD-WAN branch location.

References :=

• [Cisco SD-WAN Cloud Interconnect with Equinix]
• [Cisco SD-WAN Cloud OnRamp for CoLocation Deployment Guide]

• 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 connectivity model that meets the requirements of high availability, redundancy, and low latency for the company’s business applications is ExpressRoute with private peering using SDCI.

• ExpressRoute is a service that provides a dedicated, private, and high-bandwidth connection between the customer’s on-premises network and Microsoft Azure cloud network1.
• Private peering is a type of ExpressRoute circuit that allows the customer to access Azure services that are hosted in a virtual network, such as virtual machines, storage, and databases2.
• SDCI (Secure Data Center Interconnect) is a Cisco solution that enables secure and scalable connectivity between multiple data centers and cloud providers, using technologies such as MPLS, IPsec, and SD-WAN3.
• By using ExpressRoute with private peering and SDCI, the company can achieve the following benefits:

References:

• What is Azure ExpressRoute?
• Azure ExpressRoute peering
• Cisco Secure Data Center Interconnect
• ExpressRoute circuit and routing domain