Cisco ACI

ACI Cisco

by Publications

Cisco ACI Components

In today's rapidly evolving technological landscape, organizations are constantly seeking innovative solutions to streamline their network infrastructure. Enter Cisco ACI Networks, a game-changing technology that promises to redefine networking as we know it. In this blog post, we will explore the key features and benefits of Cisco ACI Networks, shedding light on how it is transforming the way businesses design, deploy, and manage their network infrastructure.

Cisco ACI, short for Application Centric Infrastructure, is an advanced networking solution that brings together physical and virtual environments under a single, unified policy framework. By providing a holistic approach to network provisioning, automation, and orchestration, Cisco ACI Networks enable organizations to achieve unprecedented levels of agility, efficiency, and scalability.

Simplified Network Management: Cisco ACI Networks simplify network management by abstracting the underlying complexity of the infrastructure. With a centralized policy model, administrators can define and enforce network policies consistently across the entire network fabric, regardless of the underlying hardware or hypervisor.

Enhanced Security: Security is a top concern for any organization, and Cisco ACI Networks address this challenge head-on. By leveraging microsegmentation and integration with leading security platforms, ACI Networks provide granular control and visibility into network traffic, helping organizations mitigate potential threats and adhere to compliance requirements.

Scalability and Flexibility: The dynamic nature of modern business demands a network infrastructure that can scale effortlessly and adapt to changing requirements. Cisco ACI Networks offer unparalleled scalability and flexibility, allowing businesses to seamlessly expand their network footprint, add new services, and deploy applications with ease.

Data Center Virtualization: Cisco ACI Networks have revolutionized data center virtualization by providing a unified fabric that spans physical and virtual environments. This enables organizations to achieve greater operational efficiency, optimize resource utilization, and simplify the deployment of virtualized workloads.

Multi-Cloud Connectivity: In the era of hybrid and multi-cloud environments, connecting and managing disparate cloud services can be a daunting task. Cisco ACI Networks facilitate seamless connectivity between on-premises data centers and various public and private clouds, ensuring consistent network policies and secure communication across the entire infrastructure.

Cisco ACI Networks offer a paradigm shift in network infrastructure, empowering organizations to build agile, secure, and scalable networks tailored to their specific needs. With its comprehensive feature set, simplified management, and seamless integration with virtual and cloud environments, Cisco ACI Networks are poised to shape the future of networking. Embrace this transformative technology, and unlock a world of possibilities for your organization.

Matt Conran

Highlights: Cisco ACI Components

The ACI Fabric

Cisco ACI is a software-defined networking (SDN) solution that integrates with software and hardware. With the ACI, we can create software policies and use hardware for forwarding, an efficient and highly scalable approach offering better performance. The hardware for ACI is based on the Cisco Nexus 9000 platform product line. The APIC centralized policy controller drives the software, which stores all configuration and statistical data.

–The Cisco Nexus Family–

To build the ACI underlay, you must exclusively use the Nexus 9000 family of switches. You can choose from modular Nexus 9500 switches or fixed 1U to 2U Nexus 9300 models. Specific models and line cards are dedicated to the spine function in ACI fabric; others can be used as leaves, and some can be used for both purposes. You can combine various leaf switches inside one fabric without any limitations.

a) Cisco ACI Fabric: Cisco ACI’s foundation lies in its fabric, which forms the backbone of the entire infrastructure. The ACI fabric comprises leaf switches, spine switches, and the application policy infrastructure controller (APIC). Each component ensures a scalable, agile, and resilient network.

b) Leaf Switches: Leaf switches serve as the access points for endpoints within the ACI fabric. They provide connectivity to servers, storage devices, and other network devices. With their high port density and advanced features, such as virtual port channels (vPCs) and fabric extenders (FEX), leaf switches enable efficient and flexible network designs.

c) Spine Switches: Spine switches serve as the core of the ACI fabric, providing high-bandwidth connectivity between the leaf switches. They use a non-blocking, multipath forwarding mechanism to ensure optimal traffic flow and eliminate bottlenecks. With their modular design and support for advanced protocols like Ethernet VPN (EVPN), spine switches offer scalability and resiliency.

d) Application Policy Infrastructure Controller (APIC): At the heart of Cisco ACI is the APIC, a centralized management and policy control plane. The APIC acts as a single control point, simplifying network operations and enabling policy-based automation. It provides a comprehensive view of the entire fabric, allowing administrators to define and enforce policies across the network.

e) Integration with Virtualization and Cloud Environments: Cisco ACI seamlessly integrates with virtualization platforms such as VMware vSphere and Microsoft Hyper-V and cloud environments like Amazon Web Services (AWS) and Microsoft Azure. This integration enables consistent policy enforcement and visibility across physical, virtual, and cloud infrastructures, enhancing agility and simplifying operations.

–ACI Architecture: Spine and Leaf–

To be used as ACI spines or leaves, Nexus 9000 switches must be equipped with powerful Cisco CloudScale ASICs manufactured using 16-nm technology. The following figure shows the Cisco ACI based on the Nexus 9000 series. Cisco Nexus 9300 and 9500 platform switches support Cisco ACI. As a result, organizations can use them as spines or leaves to utilize an automated, policy-based systems management approach fully. 

Cisco ACI Components
Diagram: Cisco ACI Components. Source is Cisco

**Hardware-based Underlay**

Server virtualization helped by decoupling workloads from the hardware, making the compute platform more scalable and agile. However, the server is not the main interconnection point for network traffic. So, we need to look at how we could virtualize the network infrastructure similarly to the agility gained from server virtualization.

**Mapping Network Endpoints**

This is carried out with software-defined networking and overlays that could map network endpoints and be spun up and down as needed without human intervention. In addition, the SDN architecture includes an SDN controller and an SDN network that enables an entirely new data center topology.

**Specialized Forwarding Chips**

In ACI, hardware-based underlay switching offers a significant advantage over software-only solutions due to specialized forwarding chips. Furthermore, thanks to Cisco’s ASIC development, ACI brings many advanced features, including security policy enforcement, microsegmentation, dynamic policy-based redirect (inserting external L4-L7 service devices into the data path), or detailed flow analytics—besides the vast performance and flexibility.

Related: For pre-information, you may find the following helpful:

  1. Data Center Security 
  2. VMware NSX

Cisco ACI Components

 Introduction to Leaf and Spine

The Cisco SDN ACI works with a Clos architecture, a fully meshed ACI network. Based on a spine leaf architecture. As a result, every Leaf is physically connected to every Spine, enabling traffic forwarding through non-blocking links. Physically, a leaf switch set creates a leaf layer attached to the spines in a full BIPARTITE graph. This means that each Leaf is connected to each Spine, and each Spine is connected to each Leaf. 

The ACI uses a horizontally elongated Leaf and Spine architecture with one hop to every host in an entirely messed ACI fabric, offering good throughput and convergence needed for today’s applications.

The ACI fabric: Does Not Aggregate Traffic

A key point in the spine-and-leaf design is the fabric concept, like a stretch network. One of the core ideas around a fabric is that it does not aggregate traffic. This does increase data center performance along with a non-blocking architecture. With the spine-leaf topology, we are spreading a fabric across multiple devices.

Required: Increased Bandwidth Available

The result of the fabric is that each edge device has the total bandwidth of the fabric available to every other edge device. This is one big difference from traditional data center designs; we aggregate the traffic by either stacking multiple streams onto a single link or carrying the streams serially.

Challenge: Oversubscription

With the traditional 3-tier design, we aggregate everything at the core, leading to oversubscription ratios that degrade performance. With the ACI Leaf and Spine design, we spread the load across all devices with equidistant endpoints, allowing us to carry the streams parallel.

Required: Routed Multipathing

Then, we have horizontal scaling load balancing.  Load balancing with this topology uses multipathing to achieve the desired bandwidth between the nodes. Even though this forwarding paradigm can be based on Layer 2 forwarding ( bridging) or Layer 3 forwarding ( routing), the ACI leverages a routed approach to the Leaf and Spine design, and we have Equal Cost Multi-Path (ECMP) for both Layer 2 and Layer 3 traffic. 

**Overlay and Underlay Design**

Mapping Traffic:

So you may be asking how we can have Layer 3 routed core and pass Layer 2 traffic. This is done using the overlay, which can map different traffic types to other overlays. So, we can have Layer 2 traffic mapped to an overlay over a routed core.

L3 active-active links: ACI links between the Leaf and the Spine switches are L3 active-active links. Therefore, we can intelligently load balance and traffic steer to avoid issues. We don’t need to rely on STP to block links or involve STP in fixing the topology.

Challenge: IP – Identity & Location

When networks were first developed, there was no such thing as an application moving from one place to another while it was in use. So, the original architects of IP, the communication protocol used between computers, used the IP address to indicate both the identity of a device connected to the network and its location on the network. Today, in the modern data center, we need to be able to communicate with an application or application tier, no matter where it is.

Required: Overlay Encapsulation

One day, it may be in location A and the next in location B, but its identity, which we communicate with, is the same on both days. An overlay is when we encapsulate an application’s original message with the location to which it needs to be delivered before sending it through the network. Once it arrives at its final destination, we unwrap it and deliver the original message as desired.

The identities of the devices (applications) communicating are in the original message, and the locations are in the encapsulation, thus separating the place from the identity. This wrapping and unwrapping is done on a per-packet basis and, therefore, must be done quickly and efficiently.

**Overlay and Underlay Components**

The Cisco SDN ACI has an overlay and underlay concept, which forms a virtual overlay solution. The role of the underlay is to glue together devices so the overlay can work and be built on top. So, the overlay, which is VXLAN, runs on top of the underlay, which is IS-IS. In the ACI, the IS-IS protocol provides the routing for the overlay, which is why we can provide ECMP from the Leaf to the Spine nodes. The routed underlay provides an ECMP network where all leaves can access Spine and have the same cost links. 

ACI overlay
Diagram: Overlay. Source Cisco

Underlay & Overlay Interaction

Example: 

Let’s take a simple example to illustrate how this is done. Imagine that application App-A wants to send a packet to App-B. App-A is located on a server attached to switch S1, and App-B is initially on switch S2. When App-A creates the message, it will put App-B as the destination and send it to the network; when the message is received at the edge of the network, whether a virtual edge in a hypervisor or a physical edge in a switch, the network will look up the location of App-B in a “mapping” database and see that it is attached to switch S2.

It will then put the address of S2 outside of the original message. So, we now have a new message addressed to switch S2. The network will forward this new message to S2 using traditional networking mechanisms. Note that the location of S2 is very static, i.e., it does not move, so using traditional mechanisms works just fine.

Upon receiving the new message, S2 will remove the outer address and thus recover the original message. Since App-B is directly connected to S2, it can easily forward the message to App-B. App-A never had to know where App-B was located, nor did the network’s core. Only the edge of the network, specifically the mapping database, had to know the location of App-B. The rest of the network only had to see the location of switch S2, which does not change.

Let’s now assume App-B moves to a new location switch S3. Now, when App-A sends a message to App-B, it does the same thing it did before, i.e., it addresses the message to App-B and gives the packet to the network. The network then looks up the location of App-B and finds that it is now attached to switch S3. So, it puts S3’s address on the message and forwards it accordingly. At S3, the message is received, the outer address is removed, and the original message is delivered as desired.

App-A did not track App-B’s movement at all. App-B’s address identified It, while the switch’s address, S2 or S3, identified its location. App-A can communicate freely with App-B no matter where It is located, allowing the system administrator to place App-B in any area and move it as desired, thus achieving the flexibility needed in the data center.

Multicast Distribution Tree (MDT)

We have a Multicast Distribution Tree MDT tree on top that is used to forward multi-destination traffic without having loops. The Multicast distribution tree is dynamically built to send flood traffic for specific protocols. Again, it does this without creating loops in the overlay network. The tunnels created for the endpoints to communicate will have tunnel endpoints. The tunnel endpoints are known as the VTEP. The VTEP addresses are assigned to each Leaf switch from a pool that you specify in the ACI startup and discovery process.

Normalize the transports

VXLAN tunnels in the ACI fabric normalize the transports in the ACI network. Therefore, traffic between endpoints can be delivered using the VXLAN tunnel, resulting in any transport network regardless of the device connecting to the fabric. 

So, using VXLAN in the overlay enables any network, and you don’t need to configure anything special on the endpoints for this to happen. The endpoints that connect to the ACI fabric do not need special software or hardware. The endpoints send regular packets to the leaf nodes they are connected to directly or indirectly. As endpoints come online, they send traffic to reach a destination.

Bridge Domains and VRF

Therefore, the Cisco SDN ACI under the hood will automatically start to build the VXLAN overlay network for you. The VXLAN network is based on the Bridge Domain (BD), or VRF ACI constructs deployed to the leaf switches. The Bridge Domain is for Layer 2, and the VRF is for Layer 3. So, as devices come online and send traffic to each other, the overlay will grow in reachability in the Bridge Domain or the VRF. 

Direct host routing for endoints

Routing within each tenant, VRF is based on host routing for endpoints directly connected to the Cisco ACI fabric. For IPv4, the host routing is based on the /32, giving the ACI a very accurate picture of the endpoints. Therefore, we have exact routing in the ACI.  In conjunction, we have a COOP database that runs on the Spines and offers remarkably optimized fabric to know where all the endpoints are located.

To facilitate this, every node in the fabric has a TEP address, and we have different types of TEPs depending on the device’s role. The Spine and the Leaf will have TEP addresses but will differ from each other.

COOP database
Diagram: COOP database

The VTEP and PTEP

The Leaf’s nodes are the Virtual Tunnel Endpoints (VTEP), which are also known as the physical tunnel endpoints (PTEP) in ACI. These PTEP addresses represent the “WHERE” in the ACI fabric where an endpoint lives. Cisco ACI uses a dedicated VRF and a subinterface of the uplinks from the Leaf to the Spines as the infrastructure to carry VXLAN traffic. In Cisco ACI terminology, the transport infrastructure for VXLAN traffic is known as Overlay-1, which is part of the tenant “infra.” 

**The Spine TEP**

The Spines also have a PTEP and an additional proxy TEP, which are used for forwarding lookups into the mapping database. The Spines have a global view of where everything is, which is held in the COOP database synchronized across all Spine nodes. All of this is done automatically for you.

**Anycast IP Addressing**

For this to work, the Spines have an Anycast IP address known as the Proxy TEP. The Leaf can use this address if they do not know where an endpoint is, so they ask the Spine for any unknown endpoints, and then the Spine checks the COOP database. This brings many benefits to the ACI solution, especially for traffic optimizations and reducing flooded traffic in the ACI. Now, we have an optimized fabric for better performance.

The ACI optimizations

**Mouse and elephant flow**

This provides better performance for load balancing different flows. For example, in most data centers, we have latency-sensitive flows, known as mouse flows, and long-lived bandwidth-intensive flows, known as elephant flows. 

The ACI has more precisely load-balanced traffic using algorithms that optimize mouse and elephant flows and distribute traffic based on flow lets: flow let load-balancing. Within a Leaf, Spine latency is low and consistent from port to port.

The max latency of a packet from one port to another in the architecture is the same regardless of the network size. So you can scale the network without degrading performance. Scaling is often done on a POD-by-POD basis. For more extensive networks, each POD would be its Leaf and Spine network.

**ARP optimizations: Anycast gateways**

The ACI comes by default with a lot of traffic optimizations. Firstly, instead of using an ARP and broadcasting across the network, that can hamper performance. The Leaf can assume that the Spine will know where the destination is ( and it does via the COOP database ), so there is no need to broadcast to everyone to find a destination.

If the Spine knows where the endpoint is, it will forward the traffic to the other Leaf. If not, it will drop it.

**Fabric anycast addressing**

This again adds performance benefits to the ACI solution as the table sizes on the Leaf switches can be kept smaller than they would if they needed to know where all the destinations were, even if they were not or never needed to communicate with them. On the Leaf, we have an Anycast address too.

These fabric Anycast addresses are available for Layer 3 interfaces. On the Leaf ToR, we can establish an SVI that uses the same MAC address on every ToR; therefore, when an endpoint needs to route to a ToR, it doesn’t matter which ToR you use. The Anycast Address is spread across all ToR leaf switches. 

**Pervasive gateway**

Now we have predictable latency to the first hop, and you will use the local route VRF table within that ToR instead of traversing the fabric to a different ToR. This is the Pervasive Gateway feature that is used on all Leaf switches. The Cisco ACI has many advanced networking features, but the pervasive gateway is my favorite. It does take away all the configuration mess we had in the past.

ACI Cisco: Integrations

  • Routing Control Platform

Then came along Cisco SDN ACI, the ACI Cisco, which operates differently from the traditional data center with an application-centric infrastructure. The Cisco application-centric infrastructure achieves resource elasticity with automation through standard policies for data center operations and consistent policy management across multiple on-premises and cloud instances.

  • Extending & Integrating the fabric

What makes the Cisco ACI interesting is its several vital integrations. I’m not talking about extending the data center with multi-pod and multi-site, for example, with AlgoSec, Cisco AppDynamics, and SD-WAN. AlgoSec enables secure application delivery and policy across hybrid network estates, while AppDynamic lives in a world of distributed systems Observability. SD-WAN enabled path performance per application with virtual WANs.

Cisco Multi-Pod Design

Cisco ACI Multi-Pod is part of the “Single APIC Cluster / Single Domain” family of solutions, as a single APIC cluster is deployed to manage all the interconnected ACI networks. These separate ACI networks are named “pods,” Each looks like a regular two-tier spine-leaf topology. The same APIC cluster can manage several pods, and to increase the resiliency of the solution, the various controller nodes that make up the cluster can be deployed across different pods.

ACI Multi-Pod
Diagram: Cisco ACI Multi-Pod. Source Cisco.

ACI Cisco and AlgoSec

With AlgoSec integrated with the Cisco ACI, we can now provide automated security policy change management for multi-vendor devices and risk and compliance analysis. The AlgoSec Security Management Solution for Cisco ACI extends ACI’s policy-driven automation to secure various endpoints connected to the Cisco SDN ACI fabric.

These simplify network security policy management across on-premises firewalls, SDNs, and cloud environments. They also provide visibility into ACI’s security posture, even across multi-cloud environments. 

ACI Cisco and AppDynamics 

Then, with AppDynamics, we are heading into Observability and controllability. Now, we can correlate app health and network for optimal performance, deep monitoring, and fast root-cause analysis across complex distributed systems with numbers of business transactions that need to be tracked.

This will give your teams complete visibility of your entire technology stack, from your database servers to cloud-native and hybrid environments. In addition, AppDynamics works with agents that monitor application behavior in several ways. We will examine the types of agents and how they work later in this post.

ACI Cisco and SD-WAN 

SD-WAN brings a software-defined approach to the WAN. These enable a virtual WAN architecture to leverage transport services such as MPLS, LTE, and broadband internet services. So, SD-WAN is not a new technology; its benefits are well known, including improving application performance, increasing agility, and, in some cases, reducing costs.

The Cisco ACI and SD-WAN integration makes active-active data center design less risky than in the past. The following figures give a high-level overview of the Cisco ACI and SD-WAN integration. For pre-information generic to SD-WAN, go here: SD-WAN Tutorial

SD WAN integration
Diagram: Cisco ACI and SD-WAN integration

The Cisco SDN ACI with SD-WAN integration helps ensure an excellent application experience by defining application Service-Level Agreement (SLA) parameters. Cisco ACI releases 4.1(1i) and adds support for WAN SLA policies. This feature enables admins to apply pre-configured policies to specify the packet loss, jitter, and latency levels for the tenant traffic over the WAN.

When you apply a WAN SLA policy to the tenant traffic, the Cisco APIC sends the pre-configured policies to a vManage controller. The vManage controller, configured as an external device manager that provides SDWAN capability, chooses the best WAN link that meets the loss, jitter, and latency parameters specified in the SLA policy.

Openshift and Cisco SDN ACI

OpenShift Container Platform (formerly known as OpenShift Enterprise) or OCP is Red Hat’s offering for the on-premises private platform as a service (PaaS). OpenShift is based on the Origin open-source project and is a Kubernetes distribution, the defacto for container-based virtualization. The foundation of the OpenShift networking SDN is based on Kubernetes and, therefore, shares some of the same networking technology along with some enhancements, such as the OpenShift route construct.

Other data center integrations

Cisco SDN ACI has another integration with Cisco DNA Center/ISE that maps user identities consistently to endpoints and apps across the network, from campus to the data center. Cisco Software-Defined Access (SD-Access) provides policy-based automation from the edge to the data center and the cloud.

Cisco SD-Access provides automated end-to-end segmentation to separate user, device, and application traffic without redesigning the network. This integration will enable customers to use standard policies across Cisco SD-Access and Cisco ACI, simplifying customer policy management using Cisco technology in different operational domains.

OpenShift and Cisco ACI

OpenShift does this with an SDN layer and enhances Kubernetes networking to create a virtual network across all the nodes. It is made with the Open Switch standard. For OpenShift SDN, this pod network is established and maintained by the OpenShift SDN, configuring an overlay network using a virtual switch called the OVS bridge. This forms an OVS network that gets programmed with several OVS rules. The OVS is a popular open-source solution for virtual switching.

OpenShift SDN plugin

We mentioned that you could tailor the virtual network topology to suit your networking requirements, which can be determined by the OpenShift SDN plugin and the SDN model you select. With the default OpenShift SDN, several modes are available. This level of SDN mode you choose is concerned with managing connectivity between applications and providing external access to them. Some modes are more fine-grained than others. The Cisco ACI plugins offer the most granular.

Integrating ACI and OpenShift platform

The Cisco ACI CNI plugin for the OpenShift Container Platform provides a single, programmable network infrastructure, enterprise-grade security, and flexible micro-segmentation possibilities. The APIC can provide all networking needs for the workloads in the cluster. Kubernetes workloads become fabric endpoints, like Virtual Machines or Bare Metal endpoints.

Cisco ACI CNI Plugin

The Cisco ACI CNI plugin extends the ACI fabric capabilities to OpenShift clusters to provide IP Address Management, networking, load balancing, and security functions for OpenShift workloads. In addition, the Cisco ACI CNI plugin connects all OpenShift Pods to the integrated VXLAN overlay provided by Cisco ACI.

Cisco SDN ACI and AppDynamics

AppDynamis overview

So, an application requires multiple steps or services to work. These services may include logging in and searching to add something to a shopping cart. These services invoke various applications, web services, third-party APIs, and databases, known as business transactions.

The user’s critical path

A business transaction is the essential user interaction with the system and is the customer’s critical path. Therefore, business transactions are the things you care about. If they start to go, your system will degrade. So, you need ways to discover your business transactions and determine if there are any deviations from baselines. This should also be automated, as learning baseline and business transitions in deep systems is nearly impossible using the manual approach.

So, how do you discover all these business transactions?

AppDynamics automatically discovers business transactions and builds an application topology map of how the traffic flows. A topology map can view usage patterns and hidden flows, acting as a perfect feature for an Observability platform.

AppDynamic topology

AppDynamics will automatically discover the topology for all of your application components. It can then build a performance baseline by capturing metrics and traffic patterns. This allows you to highlight issues when services and components are slower than usual.

AppDynamics uses agents to collect all the information it needs. The agent monitors and records the calls that are made to a service. This is from the entry point and follows executions along its path through the call stack. 

Types of Agents for Infrastructure Visibility

If the agent is installed on all critical parts, you can get information about that specific instance, which can help you build a global picture. So we have an Application Agent, Network Agent, and Machine Agent for Server visibility and Hardware/OS.

  • App Agent: This agent will monitor apps and app servers, and example metrics will be slow transitions, stalled transactions, response times, wait times, block times, and errors.  
  • Network Agent: This agent monitors the network packets, TCP connection, and TCP socket. Example metrics include performance impact Events, Packet loss, and retransmissions, RTT for data transfers, TCP window size, and connection setup/teardown.
  • Machine Agent Server Visibility: This agent monitors the number of processes, services, caching, swapping, paging, and querying. Example Metrics include hardware/software interrupts, virtual memory/swapping, process faults, and CPU/DISK/Memory utilization by the process.
  • Machine Agent: Hardware/OS – disks, volumes, partitions, memory, CPU. Example metrics: CPU busy time, MEM utilization, and pieces file.

Automatic establishment of the baseline

A baseline is essential, a critical step in your monitoring strategy. Doing this manually is hard, if not impossible, with complex applications. It is much better to have this done automatically. You must automatically establish the baseline and alert yourself about deviations from it.

This will help you pinpoint the issue faster and resolve it before it can be affected. Platforms such as AppDynamics can help you here. Any malicious activity can be seen from deviations from the security baseline and performance issues from the network baseline.

Summary: Cisco ACI Components

In the ever-evolving world of networking, organizations are constantly seeking ways to enhance their infrastructure’s performance, security, and scalability. Cisco ACI (Application Centric Infrastructure) presents a cutting-edge solution to these challenges. By unifying physical and virtual environments and leveraging network automation, Cisco ACI revolutionizes how networks are built and managed.

Understanding Cisco ACI Architecture

At the core of Cisco ACI lies a robust architecture that enables seamless integration between applications and the underlying network infrastructure. The architecture comprises three key components:

1. Application Policy Infrastructure Controller (APIC):

The APIC serves as the centralized management and policy engine of Cisco ACI. It provides a single point of control for configuring and managing the entire network fabric. Through its intuitive graphical user interface (GUI), administrators can define policies, allocate resources, and monitor network performance.

2. Nexus Switches:

Cisco Nexus switches form the backbone of the ACI fabric. These high-performance switches deliver ultra-low latency and high throughput, ensuring optimal data transfer between applications and the network. Nexus switches provide the necessary connectivity and intelligence to enable the automation and programmability features of Cisco ACI.

3. Application Network Profiles:

Application Network Profiles (ANPs) are a fundamental aspect of Cisco ACI. ANPs define the policies and characteristics required for specific applications or application groups. By encapsulating network, security, and quality of service (QoS) policies within ANPs, administrators can streamline the deployment and management of applications.

The Power of Network Automation

One of the most compelling aspects of Cisco ACI is its ability to automate network provisioning, configuration, and monitoring. Through the APIC’s powerful automation capabilities, network administrators can eliminate manual tasks, reduce human errors, and accelerate the deployment of applications. With Cisco ACI, organizations can achieve greater agility and operational efficiency, enabling them to rapidly adapt to evolving business needs.

Security and Microsegmentation with Cisco ACI

Security is a paramount concern for every organization. Cisco ACI addresses this by providing robust security features and microsegmentation capabilities. With microsegmentation, administrators can create granular security policies at the application level, effectively isolating workloads and preventing lateral movement of threats. Cisco ACI also integrates with leading security solutions, enabling seamless network enforcement and threat intelligence sharing.

Conclusion

Cisco ACI is a game-changer in the realm of network automation and infrastructure management. Its innovative architecture, coupled with powerful automation capabilities, empowers organizations to build agile, secure, and scalable networks. By leveraging Cisco ACI’s components, businesses can unlock new levels of efficiency, flexibility, and performance, ultimately driving growth and success in today’s digital landscape.

OpenShift Networking Deep Dive

OpenShift SDN

by Publications

OpenShift SDN

In the world of networking, Openshift SDN stands out as a powerful and innovative solution. With its cutting-edge features and flexible architecture, it has revolutionized the way we approach software-defined networking. In this blog post, we will dive deep into Openshift SDN, exploring its key components, benefits, and practical use cases.

Openshift SDN, short for Openshift Software-Defined Networking, is a robust platform that enables efficient and scalable networking in containerized environments. It leverages various technologies such as Open vSwitch and OpenFlow to provide a comprehensive networking solution for modern applications. By decoupling the network control plane from the data plane, Openshift SDN offers enhanced flexibility and agility.

a) Open vSwitch: At the heart of Openshift SDN lies Open vSwitch, a virtual switch that enables network virtualization and bridges the gap between physical and virtual networks. It allows for seamless communication between containers and facilitates the creation of logical networks with advanced features like VLAN tagging and QoS.

b) OpenFlow: Openshift SDN relies on the OpenFlow protocol to manage and control network flows. OpenFlow enables centralized management and programmability, allowing administrators to define and enforce network policies with ease. This dynamic control over network traffic ensures efficient resource utilization and improved network performance.

a) Enhanced Scalability: Openshift SDN provides a scalable networking solution that can handle the demands of modern applications. Its ability to dynamically provision and manage network resources ensures smooth scalability as your application needs grow.

b) Improved Security: With Openshift SDN, security becomes a top priority. The platform offers robust isolation between containers, preventing unauthorized access and potential breaches. Network policies can be defined and enforced at a granular level, ensuring strict control over traffic flow.

c) Simplified Operations: Openshift SDN simplifies network management by providing a centralized control plane. Administrators can easily configure, monitor, and troubleshoot the network, reducing operational complexities and minimizing downtime.

a) Microservices Architecture: Openshift SDN is particularly well-suited for microservices-based applications. Its flexible networking capabilities allow for seamless communication between microservices, enabling efficient scaling and load balancing.

b) Hybrid Cloud Environments: In hybrid cloud deployments, Openshift SDN acts as a bridge, connecting on-premises infrastructure with cloud resources. It ensures secure and reliable communication between different environments, providing a consistent networking experience.

Matt Conran

Highlights: OpenShift SDN

The Role of SDN

OpenShift SDN (Software Defined Network) is a software-defined networking solution designed to make it easier for organizations to manage their network traffic in the cloud. It is a network overlay technology that enables distributed applications to communicate over public and private networks.

OpenShift SDN is based on the Open vSwitch (OVS) platform and provides a secure, reliable, and highly available layer 3 network overlay. With OpenShift SDN, users can define their network topologies, create virtual networks, and control traffic flows between virtual machines and containers.

One of the standout features of OpenShift SDN is its ability to support multiple network isolation policies. This is carried out with the use of a network plugin. This ensures that applications can run securely without interfering with one another. Additionally, OpenShift SDN integrates seamlessly with Kubernetes, leveraging its capabilities to manage network policies, services, and routes efficientl

OpenShift Network Plugins:

OpenShift SDN uses a network plugin that provides a flexible and efficient way to connect containers across nodes in a cluster. It abstracts the underlying network complexities via the network overlay, enabling seamless communication between pods. OpenShift SDN is designed to meet the high demands of modern applications, providing secure and scalable networking solutions.

**OpenShift Networking SDN**

1. To start OpenShift networking SDN, we have the Route constructs to provide access to specific services from the outside world. So, there is a connection point between the Route and the service construct. First, the Route connects to the service; then, the service acts as a software load balancer to the correct pod or pods with your application.

2. With the default of cluster-IP, several different service types can exist. So, you may consider the service the first level of exposing applications, but they are unrelated to DNS name resolution. To make servers accepted by FQDN, we use the OpenShift route resource, which provides the DNS.

3. The default service cluster IP addresses are from the OpenShift Dedicated internal network, which permits pods to access each other. Services are assigned an IP address and port pair that, when accessed, proxy to an appropriate backing pod.

4. By default, unsecured routes are configured and are, therefore, the easiest to configure. A secured route, however, offers security that keeps your connection private. Create secure HTTPS routes using the create route command and optionally supplying certificates and keys (PEM-format files that must be generated and signed separately).

Personal Note: Application Exposure

– When considering OpenShift and how OpenShift networking SDN works, you need to fully understand how application exposure works and how to expose yourself to the external world so that external clients can access your internal application.

– For most use cases, the applications running in Kubernetes ( see Kubernetes networking 101 ) pods’ containers need to be exposed, and this is not done with the pod IP address. Due to the fact that pods IP can be ephmemeral.

– Instead, the pods are given IP addresses for different use cases. Application exposure is done with OpenShift routes and OpenShift services. The construct used depends on the level of exposure needed. 

Related: For pre-information, kindly visit the following:

  1. OpenShift Security Best Practices
  2. ACI Cisco
  3. DNS Security Solutions
  4. Container Networking
  5. OpenStack Architecture
  6. Kubernetes Security Best Practice

OpenShift SDN

Kuberenetes Concepts

Kubernetes’ concept of a POD

As the smallest compute unit that can be defined, deployed, and managed, OpenShift leverages the Kubernetes concept of a pod. There is one or more containers deployed on one host. A pod is the equivalent of a physical or virtual machine instance to a container. Containers within pods can share their local storage and networking, as each pod has its IP address.

An individual pod has a lifecycle; it is defined, assigned to a node, and then runs until the container(s) exit or are removed for some other reason. Pods can be removed after exiting or retained to allow access to container logs, depending on policy and exit code.

In OpenShift, pod definitions are largely immutable; they cannot be modified while running. Changes are implemented by terminating existing pods and recreating them with modified configurations, base images, or both. Additionally, pods are expendable and do not maintain their state when recreated. In general, pods should not be managed directly by users but by higher-level controllers.

Kubernetes PODKubernetes’ Concept of Services

Kubernetes services act as internal load balancers. They identify a set of replicated pods to proxy connections to them. While the service remains consistently available, backing pods can be added or removed arbitrarily, enabling everything that depends on them to refer to them at a consistent address. This is a key abstraction layer a a Kubernetes design. Additionally, the OpenShift Container Platform uses cluster IP addresses to allow pods to communicate with each other and access the internal network.

Note: The service can be assigned additional external IP and ingress IP addresses outside the cluster to allow external access. An external IP address can also be a virtual IP address that provides highly available access to the service.

Services are assigned IP addressing and port mappings, which proxy to an appropriate backing pod when accessed. Using a label selector, a service can find all containers running on a specific port that provides a particular network service. Like pods, services are REST objects. 

Kubernetes service

There are a couple of options for getting hands-on with OpenShift. You can download the CodeReady Containers for Linux, Microsoft, and MacOS or RedHat’s pre-built Sandbox Lab environment.

Configuring OpenShift Cluster

### Getting Started: Setting Up Your OpenShift Environment

Before diving into configuration, it’s essential to set up your OpenShift environment correctly. Start by installing the OpenShift CLI (oc) and setting up access to your cluster. For beginners, Red Hat offers OpenShift Online, which provides a managed cloud service to ease you into the ecosystem. Ensure your local development environment is compatible and includes the necessary tools such as Docker and Kubernetes.

—

### Configuring Your OpenShift Cluster: Step-by-Step

1. **Networking:** Begin by configuring the cluster networking. OpenShift uses a Software-Defined Network (SDN) to manage communication between pods. Choose a suitable network plugin, like OVN-Kubernetes or Calico, and configure the network policies to secure your application traffic.

2. **Storage:** Proper storage configuration is vital for stateful applications. OpenShift supports various storage solutions, including Persistent Volumes (PVs) and Persistent Volume Claims (PVCs). Evaluate your storage needs and select appropriate storage classes to ensure data persistence and redundancy.

3. **Security:** OpenShift offers robust security features. Configure role-based access control (RBAC) to restrict user permissions and define security contexts for your pods. Implement network security policies and enable cluster auditing to monitor and respond to potential threats.

4. **Resource Management:** Efficient resource allocation ensures optimal performance. Configure resource quotas and limits to prevent overconsumption. Utilize Horizontal Pod Autoscalers (HPAs) to automatically adjust the number of pods based on current demand.

—

### Advanced Configuration: Enhancing Your Cluster

For those looking to further optimize their OpenShift cluster, consider implementing advanced configurations:

– **Monitoring and Logging:** Deploy tools like Prometheus and Grafana for monitoring, and Elasticsearch, Fluentd, and Kibana (EFK) stack for logging. These tools offer insight into cluster performance and help troubleshoot issues quickly.

– **CI/CD Integration:** Integrate OpenShift with your existing CI/CD pipeline using tools like Jenkins or GitLab. This integration allows for automated builds, tests, and deployments, enhancing your development workflow.

– **Custom Operators:** Leverage OpenShift’s Operator Framework to automate the management of complex applications. Operators can significantly reduce manual intervention and streamline application lifecycle management.

OpenShift Networking Deep Dive

### The Basics of OpenShift Networking

OpenShift networking is built on the foundation of Kubernetes, but with enhancements that cater to enterprise needs. At its core, OpenShift uses an overlay network to manage communication between pods across nodes. This network ensures seamless connectivity and scalability, allowing applications to function efficiently in a distributed environment. By default, OpenShift uses Open vSwitch (OVS) as its software-defined networking (SDN) solution, which provides flexibility and control over network traffic.

### Key Components of OpenShift Networking

Understanding the components that make up OpenShift networking is essential for effective network management. The primary components include:

1. **Pods and Services:** Pods are the smallest deployable units in OpenShift, and services provide a stable endpoint for accessing these pods.

2. **Ingress and Egress Traffic:** OpenShift manages ingress traffic via routes, which define how external users access the services. Egress traffic, on the other hand, involves controlling the outbound connections from the pods to external services.

3. **Network Policies:** These policies define the rules for communication between pods. By implementing network policies, you can enhance security by restricting the flow of traffic between different parts of your application.

### Advanced Networking Features

OpenShift offers advanced networking features that cater to specific enterprise needs. Some of these features include:

– **Multi-Cluster Networking:** OpenShift supports the deployment of applications across multiple clusters, enabling organizations to achieve high availability and disaster recovery.

– **Service Mesh Integration:** With the rise of microservices, service mesh solutions like Istio are integrated into OpenShift to manage service-to-service communication, providing observability, traffic management, and security.

– **Custom DNS and Load Balancing:** OpenShift allows for custom DNS configurations and integrates with various load balancers to distribute traffic efficiently across nodes.

Service Discovery and DNS

Applications depend on each other to deliver information to users. These relationships are complex to manage in an application spanning multiple independently scalable pods. So, we don’t access applications by pod IP. These IP addresses will change for one reason, and it’s not a scalable solution.

To make this easier, OpenShift deploys DNS when the cluster is deployed and makes it available on the pod network. DNS in OpenShift allows pods to discover the resources in the OpenShift SDN.

Layer Approach to DNS.

DNS in the Openshift is a layered approach. Originally, DNS in Kubernetes was used for service discovery. The problem was solved a long time ago. DNS was the answer for service discovery back then, and it still is. Service Discovery means an application or service inside; it can reference a service by name, not an IP address.

The deployed pods represent microservices. A Kubernetes service points to these pods and discovers them by DNS name, so the service is transparent. The internal DNS manages this in Kubernetes; originally, it was SKYDNS KubeDNS, and now it’s Core DNS.

The DNS Operator

The DNS operator runs DNS services and uses Core DNS. The pods use the internal Core DNS server for DNS resolution. The pod’s DNS name server is automatically set to the Core DNS. OpenShift provides its internal DNS, implemented via Core DNS and dnsmasq for service discovery. The dnsmasq is a lightweight DNS forwarder that provides DNS. 

The DNS Operator has several roles:

    1. It creates the default cluster DNS name cluster. local
    2. Assigns DNS names to namespaces. The namespace is part of the FQDN.
    3. Assign DNS names to services. So, both the service and namespace are part of the FQDN name.
OpenShift DNS Operator
Diagram: OpenShift DNS Operator. Source OpenShift Docs.

OpenShift SDN and the DNS processes

**The Controller nodes

The OpenShift cluster network has several components. First, we have a controller node. There are multiple controller nodes in a cluster. The controller nodes redirect traffic to the PODs. We run a route on each controller node and use Core DNS. So, in front of the Kubernetes cluster or layer, this is a hardware load balancer. Then, we have external DNS, which is outside of the cluster. 

This external DNS has a wildcard domain; thus, external DNS is resolved to the frontend hardware load balancer through the wildcard. So, users who want to access a service issue the request and contact external DNS for name resolution.

Then, external resolves the wildcard domain to the load balancer, which will load balance to the different control nodes. For these control nodes, we can address the route and service.

**OpenShift and DNS: Wildcard DNS.

OpenShift has an internal DNS server that is reachable only by Pods. We need an external DNS server configured with wildcard DNS to make the service available by name to the outside. The wildcard DNS is resolved to all resources created in the cluster domain by fixing the OpenShift load balancer. 

This OpenShift load balancer provides a frontend to the control nodes run as ingress controllers and part of the cluster. They have access to internal resources and are part of the internal cluster.

**OpenShift ingress operators

For this to work, we need to use the OpenShift Operators. The Ingress Operator implements the IngressController API and enables external access to OpenShift Container Platform cluster services. It does this by deploying one or more HAProxy ingress controllers to handle the routing side.

You can use the Ingress Operator to route traffic by specifying the OpenShift Container Platform route construct. You may also have heard of the Kubernetes Ingress resources. Both are similar, but the OpenShift route can have additional security features and the use case of split green deployments.

The OpenShift Route Construct and Encryption

The OpenShift Container Platform route provides traffic to services in the cluster. Routes also offer advanced features that might not be supported by standard Kubernetes Ingress Controllers, such as TLS re-encryption, TLS passthrough, and split traffic for blue-green deployments.

In Kubernetes’s words, we use Ingress, which exposes services to the external world. However, in Openshift, it is best practice to use a routing set, which is an alternative to Ingress.

We have three Pods, each with a different IP address. To access these Pods, we need a service. Essentially, this service provides a load balancing service and distributes load to the pods using a load balancing algorithm, a round robin by default.

The service is an internal component, and in Openshift, we have routes that provide a URL for the services so they can be accessible from the outside world. So, the URL created by the Route points to the service, and the service points to the pods. In the Kubernetes world, Ingress pointed out the benefits, not routes.

Different types of services

Type: 

  • ClusterIP: The Service is exposed as an IP address internal to the cluster. This is useful for a microservices design where the front end connects to the backend without exposing the service externally. These are the Default Types. The service type is ClusterIP, meaning you have a cluster-wide IP address.
  • Node Port: This is a service type that exposes a port on the node’s IP address. This is like port forwarding on the physical node. However, the node port does not connect the internal cluster pods to a port dynamically exposed on the physical node. So external users can connect to the port on the node, and we get the port forwarded to the node port. This then goes to the pods and is load-balanced to the pods.
  • Load Balancer: You can find a service type in public cloud environments. 

Forming the network topology

OpenShift SDN networking

New pod creation: OpenShift networking SDN

As new pods are created on a host, the local OpenShift software-defined network (SDN) allocates and assigns an IP address from the cluster network subnet assigned to the node and connects the veth interface to a port in the br0 switch. It does this with the OpenShift OVS, which programs OVS rules via the OVS bridge. At the same time, the OpenShift SDN injects new OpenFlow entries into the OVSDB of br0 to Route traffic addressed to the newly allocated IP Address to the correct OVS port connecting the pod.

Pod network: 10.128.0.0/14

The pod network defaults to use the 10.128.0.0/14 IP address block. Each node in the cluster is assigned a /23 CIDR IP address range from the pod network block. That means, by default, each application node in OpenShift can accommodate a maximum of 512 pods. 

OpenFlow manages how IP addresses are allocated to each application node. The primary CNI plugin, the essence of SDN for Openshift, establishes the cluster-wide network and configures the overlay network using the OVS.

OpenShift CNI SDN Plugin

OVS is used in your OpenShift cluster as the communications backbone for your deployed pods. OVS in and out of every pod affects traffic in and out of the OpenShift cluster. OVS runs as a service on each node in the cluster. The Primary CNI SDN Plugin uses network policies using Openvswitch flow rules, which dictate which packets are allowed or denied. 

Configuring OpenShift Networking SDN

When you deploy OpenShift, the default configuration for the pod network’s topology is a single flat network. Every pod in every project can communicate without restrictions. OpenShift SDN uses a plugin architecture that provides different network topologies. Depending on your network and security requirements, you can choose a plugin that matches your desired topology. Currently, three OpenShift SDN plugins can be enabled in the OpenShift configuration without significantly changing your cluster.

OpenShift SDN default CNI network provider

OpenShift Container Platform uses a software-defined networking (SDN) approach to provide a unified cluster network that enables communication between pods across the OpenShift Container Platform cluster. The OpenShift SDN establishes and maintains this pod network, configuring an overlay network using Open vSwitch (OVS).

OpenShift SDN modes:

OpenShift SDN provides three SDN modes for configuring the pod network.

  1. ovs-subnet— Enabled by default. Creates a flat pod network, allowing all project pods to communicate.
  2. ovs-multitenant—Separates the pods by project. Applications deployed in a project can only communicate with pods deployed in the same project. 
  3. ovs-network policy: This plugin provides fine-grained Ingress and egress rules for applications. It can be more complex than the other two.

    • OpenShift ovs-subnet

The OpenShift ovs-subnet is the original OpenShift SDN plugin. This plugin provides basic connectivity for the Pods. This network connectivity is sometimes called a “flat” pod network. It is described as a “flat” Pod network because there are no filters or restrictions, and every pod can communicate with every other Pod and Service in the cluster. Flat network topology for all pods in all projects lets all deployed applications communicate. 

    • OpenShift ovs-multitenant

With OpenShift ovs-multitenant plugin, each project receives a unique VXLAN ID known as a Virtual Network ID (VNID). All the pods and services of an OpenShift Project are assigned to the corresponding VNID. So now we have segmentation based on the VNID. Doing this maintains project-level traffic isolation, meaning that Pods and Services of one Project can only communicate with Pods and Services in the same project. There is no way for Pods or Services from one project to send traffic to another. The ovs-multitenant plugin is perfect if just having projects separated is enough.

Unique across projects

Unlike the ovs-subnet plugin, which passes all traffic across all pods, this one assigns the same VNID to all pods for each project, keeping them unique across projects. It also sets up flow rules on the br0 bridge to ensure that traffic is only allowed between pods with the same VNID.

VNID for each Project

When the ovs-multitenant plugin is enabled, each project is assigned a VNID. The VNID for each Project is maintained in the etcd database on the OpenShift master node. When a pod is created, its linked veth interface is associated with its Project’s VNID, and OpenFlow rules are made to ensure it can communicate only with pods in the same project.

    • The ovs-network policy plugin 

The ovs-multitenant plugin cannot control access at a more granular level. This is where the Ovs-network policy plugin steps in, add more configuration power and lets you create custom NetworkPolicy objects. As a result, the ovs-network policy plugin provides fine-grained access control for individual applications, regardless of their project. By isolating policy using network policy objects, you can tailor your topology requirement.

This is the Kubernetes Network Policy, so you map, Label, or tag your application, then define a network policy definition to allow or deny connectivity across your application. Network policy mode will enable you to configure their isolation policies using NetworkPolicy objects. Network policy is the default mode in OpenShift Container Platform 4.8.

  • OpenShift OVN Kubernetes CNI network provider

OpenShift Container Platform uses a virtualized network for pod and service networks. The OVN-Kubernetes Container Network Interface (CNI) plugin is a network provider for the default cluster network. OVN-Kubernetes is based on the Open Virtual Network (OVN) and provides an overlay-based networking implementation. A cluster that uses the OVN-Kubernetes network provider also runs Open vSwitch (OVS) on each node. OVN configures OVS on each node to implement the declared network configuration.

OVN-Kubernetes features

The OVN-Kubernetes Container Network Interface (CNI) cluster network provider implements the following features:

  • Uses OVN (Open Virtual Network) to manage network traffic flows. OVN is a community-developed, vendor-agnostic network virtualization solution.
  • Implements Kubernetes network policy support, including ingress and egress rules.
  • It uses the Geneve (Generic Network Virtualization Encapsulation) protocol rather than VXLAN to create an overlay network between nodes.

Summary: OpenShift SDN

OpenShift SDN, short for Software-Defined Networking, is a revolutionary technology that has transformed the way we think about network management in the world of containerization. In this blog post, we delved deep into the intricacies of OpenShift SDN and explored its various components, benefits, and use cases. So, fasten your seatbelts as we embark on this exciting journey!

Understanding OpenShift SDN

OpenShift SDN is a networking plugin for the OpenShift Container Platform that provides a robust and scalable network infrastructure for containerized applications. It leverages the power of Kubernetes and overlays network connectivity on top of existing physical infrastructure. OpenShift SDN offers unparalleled flexibility, agility, and automation by decoupling the network from the underlying infrastructure.

Key Components of OpenShift SDN

To comprehend the inner workings of OpenShift SDN, let’s explore its key components:

1. Open vSwitch: Open vSwitch is a virtual switch that forms the backbone of OpenShift SDN. It enables the creation of logical networks and provides advanced features like load balancing, firewalling, and traffic shaping.

2. SDN Controller: The SDN controller is responsible for managing and orchestrating the network infrastructure. It acts as the brain of OpenShift SDN, making intelligent decisions regarding network policies, routing, and traffic management.

3. Network Overlays: OpenShift SDN utilizes network overlays to create virtual networks on top of the physical infrastructure. These overlays enable seamless communication between containers running on different hosts and ensure isolation and security.

Benefits of OpenShift SDN

OpenShift SDN brings a plethora of benefits to containerized environments. Some of the notable advantages include:

1. Simplified Network Management: With OpenShift SDN, network management becomes a breeze. It abstracts the complexities of the underlying infrastructure, allowing administrators to focus on higher-level tasks and reducing operational overhead.

2. Scalability and Elasticity: OpenShift SDN is highly scalable and elastic, making it suitable for dynamic containerized environments. It can easily accommodate the addition or removal of containers and adapt to changing network demands.

3. Enhanced Security: OpenShift SDN provides enhanced security for containerized applications by leveraging network overlays and advanced security policies. It ensures isolation between different containers and enforces fine-grained access controls.

Use Cases for OpenShift SDN

OpenShift SDN finds numerous use cases across various industries. Some prominent examples include:

1. Microservices Architecture: OpenShift SDN seamlessly integrates with microservices architectures, enabling efficient communication between different services and ensuring optimal performance.

2. Multi-Cluster Deployments: OpenShift SDN is well-suited for multi-cluster deployments, where containers are distributed across multiple clusters. It simplifies network management and enables seamless inter-cluster communication.

In conclusion, OpenShift SDN is a game-changer in the world of container networking. Its software-defined approach, coupled with advanced features and benefits, empowers organizations to build scalable, secure, and resilient containerized environments. Whether you are deploying microservices or managing multi-cluster setups, OpenShift SDN has got you covered. So, embrace the power of OpenShift SDN and unlock new possibilities for your containerized applications!