Simplify Network Segmentation for Hybrid Cloud

Introduction

Enterprises have always had the need to maintain separate development and production environments. Operational efficiency, reduction of blast radius, security and compliance are generally the common objectives behind separating these environments. By dividing networks into smaller, isolated segments, organizations can enhance security, optimize performance, and ensure regulatory compliance. This article demonstrates a practical strategy for implementing network segmentation in modern multicloud environments that also connect on-prem infrastructure. This uses F5 Distributed Cloud (F5 XC) services to connect and secure network segments in cloud environments like Amazon Web Services (AWS) and on-prem datacenters.

Need for Segmentation

Network segmentation is critical for managing complex enterprise environments. Traditional methods like Virtual Routing and Forwarding (VRFs) and Multiprotocol Label Switching (MPLS) have long been used to create isolated network segments in on-prem setups. F5 XC ensures segmentation in environments like AWS and it can extend the same segmentation to on-prem environments. These techniques separate traffic, enhance security, and improve network management by preventing unauthorized access and minimizing the attack surface.

Scenario Overview

Our scenario depicts an enterprise with three different environments (prod, dev, and shared services) extended between on-prem and cloud. A 3rd party entity requires access to a subset of the enterprise's services.

This article, covers the following two networking segmentation use-cases:

Hybrid Cloud Transit
Extranet (servicing external 3^rd party partners/customers)

Hybrid Cloud Transit

Consider an enterprise with three distinct environments: Production (Prod), Development (Dev), and Shared Services. Each environment requires strict isolation to ensure security and performance. Using F5 XC Cloud Connect, we can assign each VPC a network segment effectively isolating the VPC’s. Segments in multiple locations (or VPC’s) can traverse F5 XC to reach distant locations whether in another cloud environment or on-prem. Network segments are isolated by default, for example, our Prod segment cannot access Shared. A segment connector is needed to allow traffic between Prod and Shared. The following diagram shows the VPC segments, ensuring complete "ships in the night" isolation between environments.

In this setup, Prod, Dev, and Shared Services environments operate independently and are completely isolated from one another at the control plane level. This ensures that any issues or attacks in one environment do not affect the others.

Customer Requirement: Shared Services Access

Many enterprises deploy common services across their organization to support internal workloads and applications. Some examples include DHCP, DNS, NTP, and NFS, services that need to be accessible to both Prod and Dev environments while keeping Prod and Dev separate from each other. Segment Connectors is a method to allow communication between two isolated segments by leaking the routes between the source and destination segments.

It is important to note that segment connector can be of type Direct or SNAT. Direct allows bidirectional communication between segments whereas the SNAT option allows unidirectional communication from the source to the destination.

Extending Segmentation to On-Premises

Enterprises already use segmented networks within their on-premises infrastructure. Extending this segmentation to AWS involves creating similar isolated segments in the cloud and establishing secure communication channels. F5 XC allows you to easily extend this segmentation from on-prem to the cloud regardless of the underlay technology.

In this scenario, communication between the on-premises Prod segment and its cloud counterpart is seamless, and the same also applies for the Dev segment. Meanwhile Dev and Prod stay separate ensuring that existing security and isolation is preserved across the hybrid environment.

Extranet

In this scenario an external entity (customer/partner) needs access to a few applications within our Prod segment. There are two different ways to enable this access, Network-centric and App-centric. Let’s refer to the external entity as Company B.

In order to connect Company B we generally need appropriate cloud credentials, but Company B will not share their cloud credentials with us. To solve this problem, F5 XC recommends using AWS STS:AssumeRole functionality whereby Company B creates an AWS IAM Role that trusts F5 XC with the minimum privileges necessary to configure Transit Gateway (TGW) attachments and TGW route table entries to extend access to the F5 XC network or network segments.

Section 1 – Network-centric Extranet

Many times, partners & customers need to access a unique subset of your enterprise’s applications. This can be achieved with F5 XC’s dedicated network segments and segment connectors.

With a segment connector for the external and prod network segments, we can give Company B access to the required HTTP service without gaining broader access to other non-Prod segments.

Locking Down with Firewall Policies

We can implement a Zero Trust firewall policy to lock down access from the external segment. By refining these policies, we ensure that third-party consumers can only access the services they are authorized to use.

Our firewall policy on the CE only allows access from the external segment to the intended application on TCP/80 in Prod.

[ec2-user@ip-10-150-10-146 ~]$ curl --head 10.1.10.100

HTTP/1.1 200 OK

Server: nginx/1.24.0 (Ubuntu)

Date: Thu, 30 May 2024 20:50:30 GMT

Content-Type: text/html

Content-Length: 615

Last-Modified: Wed, 22 May 2024 21:35:11 GMT

Connection: keep-alive

ETag: "664e650f-267"

Accept-Ranges: bytes

[ec2-user@ip-10-150-10-146 ~]$ ping -O 10.1.10.100

PING 10.1.10.100 (10.1.10.100) 56(84) bytes of data.

no answer yet for icmp_seq=1

no answer yet for icmp_seq=2

no answer yet for icmp_seq=3

--- 10.1.10.100 ping statistics ---

4 packets transmitted, 0 received, 100% packet loss, time 3153ms

After applying the new policies, we confirm that the third-party access is restricted to the intended services only, enhancing security and compliance.

This demonstrates how F5 Distributed Cloud services enable networking segmentation across on-prem and cloud environments, with granular control over security policies applied between the segments.

Section 2 - App-centric Extranet

In the scenario above, Company B can directly access one or more services in Prod with a segment connector and we’ve locked it down with a firewall policy. For the App-centric method, we’ll only publish the intended services that live in Prod to the external segment.

App-centric connectivity is made possible without a segment connector by using load balancers within App Connect that target the application within the Prod segment and advertises its VIP address to the external segment. The following illustration shows how to configure each component in the load balancer.

Visualization of Traffic Flows

The visualization flow analysis tool in the F5 XC Console shows traffic flows between the connected environments. By analyzing these flows, particularly between third-party consumers and the Prod environment, we can identify any unintended access or overreach.

The following diagram is for a Network-centric connection flow:

This following diagram shows an App-centric connection flow using the load balancer:

Product Feature Demo

Conclusion

Effective network segmentation is a cornerstone of secure and efficient cloud environments. We’ve discussed how F5 XC enables hybrid cloud transit and extranet communication. Extranet can be done with either a network centric or app-centric deployment.

F5 XC is an end to end platform that manages and orchestrates end-to-end segmentation and security in hybrid-cloud environments. Enterprises can achieve comprehensive segmentation, ensuring isolation, secure access, and compliance. The strategies and examples provided demonstrate how to implement and manage segmentation across hybrid environments, catering to diverse requirements and enhancing overall network security.

Additional Resources

More features and guidance are provided in the comprehensive guide below, where showing exactly how you can use the power and flexibility of F5 Distributed Cloud and Cloud Connect to deliver a Network-centric approach with a firewall and an App-centric approach with a load balancer. Create and manage segmented networks in your own cloud and on-prem environments, and achieve the following benefits:

Ability to isolate environments within AWS
Ability to extend segmentation to on-prem environments
Ability to connect external partners or customers to a specific segment
Use Enhanced Firewall Policies to limit access and reduce the blast radius
Enhance the compliance and regulatory requirements by isolating sensitive data and systems
Visualize and monitor the traffic flows and policies across segments and network domains