EAP Documentation - Configuring ZTNA as a service


ZTNA or Zero Trust Network Access, as the name implies is founded on the principle of trust nothing, verify everything. Sophos ZTNA provides
an elegant zero-trust solution for secure remote-access to network applications and data. It verifies the user’s identity and optionally the health of
their device while securely connecting the user directly to the application enabling improved micro-segmentation, better security, and protection
from Ransomware and attacks, with a better user experience than other remote access technologies like VPN.

In this EAP, we introduce a new deployment mode, ZTNA as a service. ZTNA admins can make use of a new Sophos-protected data-plane cloud
to provide access to internal resources. The multi-tenanted Sophos cloud works to further isolate network deployments from direct internet
exposure and reduces the attack surface area. Admins can easily connect their users to applications without the hassle of opening firewall ports
and NAT policy.

ZTNA connectors are supported on VMware ESXi, AWS, and Hyper-V in this EAP. Admins can choose from multiple geo points of presence to
provide access to their internal resources.
This document is a step by step guide for the admin to configure and deploy a ZTNAaaS Connector and resources behind it. This explains both
the agent-less and agent flow. While the configuration flow is largely similar to existing configuration of gateways, there are a few updates to the
following sections:

  1. IfZTNA as a service needs to be configured, domain ownership needs to be validated
  2. While adding ZTNA connectors, you can choose the desired points of presence on Sophos Cloud. Currently we support 6 points of
    presence. Choosing a PoP nearest to where applications are hosted helps in reducing latency
  3. Public DNS server settings. CNAME records for the alias domains for ZTNA connectors and agentless resources will have to be added

Pre-Deployment Requirements

Before the admin sets up ZTNAaaS connector, they must meet the following requirements. The pre-requisites for setting up a ZTNA
connector are similar to those mentioned while connecting a ZTNA Gateway. The list can be seen here:


DNS management

You need an external DNS server for the following:

  • Verify the domain ownership that admin is going to use for ZTNAaaS connector
  • Resolve the CNAME record of connector to point to the alias domain generated for the ZTNAaaS connector.
  • Resolve the CNAME record of resources to point to the alias domain generated for the resources.

More details can be found in later sections

The domain name of your resources must match that of your connector. For example:

Connector FQDN: https://ztna.mycompany.net/
Resource FQDN: https://wiki.mycompany.net/#all-updates

Wildcard certificate

You need a wildcard certificate for the ZTNAaaS connector. Use one of the following:

  • A certificate issued from Let's Encrypt.
  • A certificate issued by a trusted certificate authority.

Azure Active Directory

You need a Microsoft Azure Active Directory account with security enabled user groups configured and synced with Sophos Central.

This guide tells you how to set up and sync these groups.

Azure Active Directory and Okta are the identity providers supported.


Infra Role Where does it exist?
1 Azure AD


  1. Authentication : Connector will federate Login Requests from User to Azure AD. This is done via Identity Provider Config in Zero Trust Network on Sophos Central.
  2. Authorization : Configure Azure AD Sync Settings in Sophos Central to sync all Users and Groups with Azure AD. This data would be used during Resource Configuration to assign Group Policies to individual Resources.

    Create Callback URI for User to get redirected back to Connector post Authentication. This will have the Connector FQDN
2 Gloabal AD Settings


Sophos Central
3 Zero Trust Network Configuration

The Configurations shown here are only with respect to recommendation of Single Arm, 3 node cluster deployment.

ZTNAaaS Supports Single Arm and Dual Arm Configurations

  • Single Arm :- Single Interface for Connector. This will be labeled as "External"
  • Dual Arm :- Dual Interfaces labelled as "External" and "Internal".

Turn on ZTNAaaS

After joining the ZTNA as a service Early Access Program (EAP), Go to Central -> ZTNA -> Settings Turn on ZTNAaaS switch. Once you turn it on, the page will refresh and will load in couple of seconds.

Note : Only if you enable this 'ZTNAaaS', will you be able to configure gateway in connector mode

  • Add the Domain and verify ownership

Go to Central ZTNA Settings

  1. Click on Domains Hyperlink

2. Click on Add Domain and add  your domain

 3. Domain will now be displayed in domains table

4. The generated TXT record/token for the domain has to be added in DNS server as a TXT record (Cloudflare is used in this example)

Note: Give few minutes after the above step before proceeding to next step.

5. Click on validate button for your domain

6. Your domain status should get changed to "Validated" by now

  • Create IDP


Go to Central -> ZTNA -> Identity Providers Add Identity Provider

Go to Central -> ZTNA -> Gateways/Connectors

  1. Click on Add Gateway/Connector. Choose the deployment mode as Connector. Choose the domain from the list of verified domains. Choose the point of presence nearest to where your datacenter is to reduce latency.

2. You will get a 'Connector Added' popup with generated alias domain for the connector; which we will use later. Connector will now be displayed in Summary Page

3. Click on Connector from Summary which will now take you to Connector Details Page. In case you need to add more instances in the cluster, click on 'Add/Edit Instances'

4. Click on Add another instance, in the below pop-up, where we will now add the remaining 2 nodes to the cluster

5. Download ISO for all nodes

  • Create Policy

Go to Central ->ZTNA -> Policies -> Add Policy

  • Select 'Agentless' and Continue

  • Give a name for Policy and save with Default Configs, where Policy is Enforced as below
  • Select 'Agent' and Continue
  • Give a name to the Policy and choose to allow 'Green OR Green and Yellow OR Green, Yellow, Red' states for device health
  • Click Save
  • Create Resources

Go to Central -> ZTNA -> Resources & Access Add resource

  • Fill in all mandatory params as below

You will get a Resource added popup which will have the alias domain. Verify Resource Created from Summary Page.
Note : Incase resource is of 'Agent' type, alias domain is not generated

Below is an example to create an Agent resource of SSH Type

  • Select the Connector from the drop down
  • Select the Policy we created in step 1
  • Select resource type eg SSH (Web App, SSH, CIFS RDP, OTHER)
  • Provide an external FQDN for the resource
  • Provide the internal FQDN for the resource
  • Select the Port type and number according to the resource selected in step 4. ( eg TCP and 22, for SSH app)
  • Select the AD user group which will be allowed to access the given resource
  • Save it

    Note : Incase resource is of 'Agent' type, alias domain is not generated

Sophos Central
4 Public DNS Server

IMPORTANT: Please note DNS entries required for Agentless and Agent based Resources are different. Find the details below

1) Below are the DNS entries required for AGENT-LESS resource access:

"CNAME" Record : Connector FQDN Connector Alias Domain

"CNAME" Record : Resource FQDN Resource Alias Domain

Note : Connector Alias Domain and Resource Alias Domain's generated are different and can be found in Connector and Resource details page in UI respectively

Connector configuration on Public DNS server:

Agentless resource configuration on public DNS server:

2) In case of AGENT based Resource access, we need to have only 1 DNS record

"CNAME" Record : Connector FQDN Connector Alias Domain

Note : Incase resource is of 'Agent' type, alias domain is not generated


  1. For agent based access, Please make sure you do not have any CNAME records for Resources.
  2. Make sure you do not add any wildcard DNS entries.

Public DNS Server
5 Private DNS Server

Connector needs to be pointing to a Private DNS Server to redirect user to actual resource post successful authentication and authorization

Alternatively, admin can directly configure the internal FQDN/IP of the resource directly


Connector Boot-UP

Follow the steps mentioned in the below link to bring up the ZTNA connector based on the chosen platform type. We currently support VMware ESXi, Hyper-V and AWS.


For ESxi and Hyper-V platforms, download the base image from the "Protect Devices"

1. Download Base Image from Protect Devices Tab on Sophos Central

Endpoint Installation with ZTNA Agent

ZTNA agent can work either with other endpoint components or as a standalone agent. In the latter case, you cannot make use of synchronized security.

Option 1: Enable ZTNA on existing Endpoint Installation

ZTNA Agent can be installed/ enabled on an already installed Endpoint.
For this you should have the 'Manage Endpoint Software' feature enabled on Central.
Once you have this enabled, go to Central Devices page
Select the device you want to install ZTNA on, and choose the 'install' option from the ZTNA dropdown and continue. You should see a tick against the ZTNA column in devices page.
Please wait for a minute before you can check the Endpoint UI , you should see a new item in the Sophos UI named - Zero Trust Network Access.

f you have a connected Gateway in Central and the ZTNA installed properly, you should see this screen on the Endpoint and ipconfig /all command will show a Sophos ZTNA TAP Adapter in the interfaces list.

c:/> ipconfig/all

Option 2: Fresh Installation

ZTNA Agent is bundled in the Endpoint and can be chosen as a thin-installer component while downloading the thin-Installer from the Central. You will be able to see this optional ZTNA component only when you have joined the ZTNA EAP program.

Accessing Userportal/Agentless Resource

  1. Type User Portal/Resource FQDN in browser

  2.  Authenticate using the user credentials. User will be displayed with the agentless resources to which he has access in user portal.
  3. User redirected to User Portal/Resource ( Post Successful Authentication & Authorization )


To provide Feedback or report any issues use the Feedback option within Sophos Central

Edited screenshots
[edited by: emmosophos at 12:19 AM (GMT -7) on 4 Nov 2022]