Important note about SSL VPN compatibility for 20.0 MR1 with EoL SFOS versions and UTM9 OS. Learn more in the release notes.

Sophos Firewall: Policy-Based IPsec with Oracle Cloud Infrastructure(OCI)

Disclaimer: This information is provided as-is for the benefit of the Community. Please contact Sophos Professional Services if you require assistance with your specific environment.


Note: The following KB is an updated version of the Sophos Firewall and Oracle Cloud Infrastructure (OCI) policy-based IPsec

Overview

This Recommended Read describes how to configure Sophos Firewall with Oracle Cloud Infrastructure VCN.

Network Diagram

Oracle Cloud Infrastructure (OCI)

It is a platform of cloud services that enables you to build and run a wide range of applications in a high-availability. For more reference, see the link www.oracle.com/.../

In OCI, the IPsec Tunnel is composed of three objects

  1. Dynamic Routing Gateway ( DRG)
  2. Customer-Premise Equipment ( CPE)
  3. IPsec Connection

Configuration

VCN

In the console, go to the Main menu>Network>Virtual Cloud Network> Create VCN

Select Compartment and insert IPv4 CIDR Blocks. For the following example we use 10.1.0.0/16 

To create a virtual Cloud Network. In Networking> Virtual Cloud Networks> Virtual Cloud Network Details

Create Subnet

In Networking>Virtual Cloud Networks>Virtual Cloud Network>Click Create Subnet.

VM Instances

VM Instances

Go to Networking>Virtual Cloud Network> Virtual Cloud Network> Create Internet Gateways.

Routing Tables

Configure the following  

  • Target Type: Internet Gateway
  • Destination CIDR Block: 0.0.0.0/0
  • Target;internetGW

Security List

To change security and turn on ICMP for testing.

Under Networking>Virtual Cloud Network>LAB> Security List Details

Dynamic Routing Gateways

Go To Networking>Customer Connectivity>Dynamic Routing Gateways

Customer-Premises Equipment( CPE)

Create CPE with ISP Address

IPsec Connection

To create a VPN, go to Networking>Customer Connectivity>Site-to-site VPN and input all the necessary information.

  • CPE
  • IKE Version
  • Oracle IKE Initiation
  • DPD
  • Phase one & Phase two Configuration

Follow the screenshot for more details.

Sophos Firewall Configuration

Version 20 firmware is used for the example. For Site-to-site VPN. kindly Go to

Configure>Site-to-site VPN

Ipsec Policies

Click the Add button and define Phase one and Phase Two as noted below

Phase 1

  • mode: main
  • Allow re-keying
  • dh group: 14
  • lifetime:28800
  • encryption aes-256
  • authentication:sha2 256

Phase 2

  • pfs group: 14
  • encryption: aes 256
  • authentication: sha1
  • keylife time: 3600

Note: Sophos will give a warning about using sha1.

Oracle Documentation states to use Sha1-96

Additional Encryption

Notes/Optional: Sometimes, vendors add support for additional encryption types before updating their documentation.

I've added a second set of encryption/Authentication to phase two settings, hoping this is the case with Oracle

  • Aes256/sha2 256

In Sophos Firewall, go to VPN> IPsec Connections

  • Add new connection
  • Type: site-to-site 
  • mode type: initiate
  • Policy: the one created above
  • Shared Secret: Defined for the primary tunnel
  • Listening Interface: This should match the WAN IP, the Oracle CPE and IPsec IKE, CPE identifier configured to receive the tunnel from
  • Gateway Address: WAN IP of the primary Oracle VPN

Note: If your Sophos WAN is behind NAT,  You can use the "Local ID" to override the IP Address presented to the IKE identifier. 

Local Networks

  • Include any on-premises network.

Note: The following must match the "Static route CIDR" values entered upon creating the IPsec connection on CLI.

Remote Networks

  • Any subnets within OCI that you desire to be reachable via tunnel

Click "Save" and then click the radio button to enable/activate the tunnel.

For Backup tunnel. The same configuration and setup will be needed. Create the backup IPsec connection on the Sophos Firewall and then proceed to the following steps:




Updated Formatting, Grammar
[edited by: Raphael Alganes at 7:51 AM (GMT -7) on 9 Oct 2024]