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Cisco Meraki

vMX Setup Guide for Microsoft Azure

Overview

This document is a walk-through for setting up a virtual MX appliance (vMX) in the Azure Marketplace. After completing the steps outlined in this document, you will have a virtual MX appliance running in the Azure Cloud that serves as an Auto VPN termination point for your physical MX devices.

Key Concepts

Before deploying a vMX, it is important to understand several key concepts.

Concentrator Mode 

All MXs can be configured in either NAT or VPN concentrator mode. There are important considerations for both modes. If needed, refer to the article on concentrator modes for more detailed information.

One-Armed Concentrator 

In this mode, the MX is configured with a single Ethernet connection to the upstream network. All traffic will be sent and received on this interface. This is the only supported configuration for MX appliances serving as VPN termination points into Azure Cloud.

NAT Mode Concentrator 

In this mode, the MX is configured with a single Ethernet connection to the upstream network and one Ethernet connection to the downstream network. VPN traffic is received and sent on the WAN interfaces connecting the MX to the upstream network and the decrypted, unencapsulated traffic is sent and received on the LAN interface that connects the MX to the downstream network. 

Note: A limited NAT mode capability can be enabled on the vMX in which traffic from the spokes will be NATed to the vMX's IP as it egresses the vMX in to your datacenter.  Other capabilities of the NAT mode including DHCP, HA or multiple ports (LAN and WAN) are not supported.  In each mode the vMX is still a one-armed appliance with one network interface

If you wish to change the concentrator mode after the vMX deployment, you must restart the instance for the changes to be applied. Please choose the desired concentrator mode before the vMX deployment.

VPN Topology

There are several options available for the structure of the VPN deployment.

Split Tunnel 

In this configuration, branches will only send traffic across the VPN if it is destined for a specific subnet that is being advertised by another MX in the same dashboard organization. The remaining traffic will be checked against other available routes, such as static LAN and third-party VPN routes, and if not matched will be NATed and sent out the branch MX unencrypted.

Full Tunnel  

In full-tunnel mode, all traffic that the branch or remote office does not have another route to is sent to a VPN hub.

Azure Cloud Terminology  

This document will make reference to several key Azure-specific terms and concepts.

Azure Virtual Network

A virtual network is where a block of associated IP addresses, DNS settings, security policies, and route tables can be configured and managed.

Azure Resource Manager (ARM) and Azure Classic

Azure has different types of virtual network environments, which represent two different methods of deploying and managing Azure virtual environments. The vMX uses managed applications, which is a Microsoft platform, and is not compatible with Azure 'classic' deployments.

Resource group 

A resource group is a container within Microsoft Azure's infrastructure where resources such as virtual machines are stored.

Azure-Managed Applications

Managed applications within Azure serve as the network used to manage and support the Cisco Meraki vMX.

Additional Information 

During the setup of your vMX instance, or over the course of working within Azure, you may encounter additional terminology which is not defined in this document. To find out more about these terms, and for additional details on the terms listed above, please see the Microsoft Azure glossary.

Meraki Dashboard Configuration 

Begin by creating a new Security Appliance network in your organization. This guide will walk you through creating a new network in the Meraki dashboard.

1. Adding license(s) to the Meraki dashboard

The Meraki Dashboard will require a vMX license to be added before you are able to continue. If you do not have access to a vMX license, please reach out to your Meraki reseller or sales rep.

Create a "Security appliance" network type: 

create_network.png

Once you have created the "Security appliance" network and added the appropriate license, you will be able to deploy a new vMX to your network by clicking on the 'Add vMX' button:

add_vmx.png

Before generating the token, please verify the firmware is running MX 15.37+, otherwise the upgrade will not occur.

2. Generate the authentication token

After you add the new vMX to your network, navigate to Security Appliance > Appliance status and select “Generate authentication token” to generate the token for the Azure "Meraki Authentication Token" data field.

auth_token.png

3. Copy the newly generated token and save it.

The newly generated token will be used in the Basics -> Instance details section when creating a new Azure-managed application.

The authentication token must be entered into the Azure instance within one hour of generating it, otherwise a new token must be generated. 

Azure Setup 

This section walks you through configuring the necessary requirements within Azure and adding a vMX instance to your Azure virtual network. For more details on setting up an Azure virtual network and other components, please refer to Microsoft Azure Documentation.

Before You Begin

You must have the following before you begin:

  • An Azure virtual network (vNET, also known as a VPC) where you will deploy the vMX.  This vNET and it's corresponding resource group can be the same one as the resources you plan to access across the Meraki VPN or a different one.  Refer to this Azure document for creating these resources. 

  • You MUST have an "SD-WAN" subnet inside the vNET where the vMX will be deployed which is separate from the subnet(s) where the resources you plan to access through the VPN are hosted.  Ex. If your apps and resources are located in the "production" subnet, you will deploy a second subnet in the same vNET called "SD-WAN" in which the vMX will be deployed.  DO NOT deploy the vMX inside the production subnet alongside the other resources as this can result in a routing loop and packet loss within the Azure environment.

A NOTE FROM AZURE:

Deploy a virtual appliance into a different subnet than the resources that route through the virtual appliance are deployed in. Deploying the virtual appliance to the same subnet, then applying a route table to the subnet that routes traffic through the virtual appliance, can result in routing loops, where traffic never leaves the subnet.

https://docs.microsoft.com/en-us/azure/virtual-network/virtual-networks-udr-overview#user-defined

This section walks you through configuring the necessary requirements within Microsoft Azure, and adding a vMX instance to your resource group. For more details on setting up a resource group and other components, please refer to Azure's documentation.

Accessing the Offer

Access to the vMX offer. A screenshot of the Marketplace list of Cisco Meraki vMX in Azure is included below:

Screen Shot 2020-11-09 at 1.05.39 PM.png

The same vMX offer is also available via Cloud Solution Providers (CSP) program on Azure.  

Deployment Steps

From the Marketplace listing, click on "Create."

After creating, you will be prompted to configure basic settings for the managed app.

Project Details

  • Subscription: Choose the subscription that you want to be billed for from the drop-down menu

  • Resource group: Create a new resource group with any name or select an existing resource group

Instance Details

  • VM name: Choose a name for your Cisco Meraki vMX VM; it can be any name

  • Meraki authentication token: Paste the token previously generated on the Meraki dashboard

  • Region: Select the region where the vMX will be deployed

  • Zone: Select the appropriate Availability Zone (AZ) for the region selected above 

Not all regions on Azure support Availability Zones (AZ). Select “NONE” for zones that don’t support AZs. If a zone is selected for a region that does not support AZs, the deployment will fail.

Screen Shot 2020-10-19 at 8.57.51 PM.png

Failure details:

Azure_AZ_Error.png

Managed Application Details

  • Application name: Choose a name for your Cisco vMX managed application

  • Managed resource group: Name for the managed resource group, which will hold all the resources that are required by the vMX managed application 

After completing the basic settings configuration, go to the next step, “Deployment Details.”

Deployment Details

  • Configure virtual networks

    • Virtual network: Choose an existing virtual network from the list; minimum allowed prefix size for the virtual network is /24 and max is /8

    • Subnet: Choose the SD-WAN subnet mentioned above in which the vMX will be deployed; if needed, refer to the article for more information about subnets in Azure.  The subnet chosen here MUST be different from the subnet where resources you plan to access and route through the vMX are deployed.

  • VM size: Choose the VM size based on the vMX SKU you want to deploy. For best performance, the new instance type of "Standard F4s_v2" should be used to deploy the vMX-S and vMX-M SKUs. 

vMX-L is currently not supported on Azure.


Next, review the deployment details and licensing information and hit "Create." 

After you click on "Create," the deployment will begin.

It may be several minutes before the deployment completes and the instance launches.  


 

Once the vMX is online, a route table needs to be created including the Auto VPN subnets so that the Azure resources know how to access the Meraki subnets over Auto VPN.

Additional Azure Route Table Configuration

To create a route table, click on "New" and then "Route Table."

Next, define the “Basics” for the new route table resource.

Route Table Basics

  • Subscription: Choose the subscription that you want to be billed for from the drop-down menu

  • Resource group: Choose an existing or a new resource group where your instances are present or will be deployed

  • Instance Details

    • Region: Select the region where the route table will be deployed

    • Name: Name for the route table instance; can be anything

    • Propagate gateway routes: Default is "Yes;" select "no" to prevent the propagation of on-premises routes to the network interfaces in associated subnets

Once the Route Table has been created, add the VPN routes pointing to the vMX as the next hop, including the client VPN subnet where applicable:

Please ignore the IP forwarding warning, it has already been enabled in the managed application template by default.


Finally, associate the Route Table with the subnet where the resources are deployed (NOT the SD-WAN subnet where the vMX is deployed). Click on "Subnets" and then "Associate.  Choose the virtual network and then choose the production subnet(s) where your applications are deployed and click "OK."

 

Once the subnet has been associated, enable site-to-site VPN on dashboard.

On the site-to-site VPN page, add each subnet in your resource group that should be accessible to remote Auto VPN peers to the list of "Local Network(s)." For more information on configuring Auto VPN, please refer to the site-to-site VPN settings documentation.

Troubleshooting 

The most common problem when deploying a vMX is getting it provisioned and online in the Meraki dashboard in the first place.  New troubleshooting/diagnosis messages have been added to the vMX console screen so you can identify what went wrong during the provisioning process.

When the vMX boots it will execute the following steps during its initial provisioning process:

  1. Obtain user data (vMX auth token)
  2. Authenticate with the dashboard (using auth token)
  3. Connect to dashboard

Obtain User Data and Authenticate to Dashboard 

Once a vMX has successfully connected to a network, it will then attempt to obtain its user data (vMX auth token). There are different user-data mechanisms in each platform that the vMX currently runs on to provide the token to the vMX. In AWS, Azure, GCP, and Alicloud there are user-data fields in the VM configuration where this can be provided. 

Token Expired 

vMX auth tokens have a lifetime of only one hour for security purposes. If you see the following message on your vMX console it means the token you provided is no longer valid.  

Token_Expired.png

Invalid Token 

If the token provided is incorrect in any way the "invalid token" message is displayed on the console.

Invalid_Token.png

Unable to Reach Meraki Dashboard 

If the vMX is unable to reach the dashboard on TCP port 7734, the initial provisioning phase will fail and an "Unable to reach Meraki Dashboard" message will be displayed on the console (check the firewall information page for a list of all the firewall rules needed for the Cisco Meraki cloud communication). Please refer to this document on the correct ports/IPs that need to be opened for Meraki dashboard communication.

 

Unable_to_Reach_Dash.png

No "Add vMX" Button 

When navigating to Security & SD-WAN > Appliance Status, if there is no "Add vMX" button, please ensure the following two conditions are met:

  1. You have available vMX licenses in your license pool.
  2. You have created a "Security appliance" network type.

Please note that Meraki support does not troubleshoot Azure Cloud-specific firewall rules and deployments.

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