📘 CCNA 200-301 v1.1
1.2 Describe Characteristics of Network Topology Architectures
1.2.f On-Premises and Cloud
This section is part of the Network Topology Architectures topic in the CCNA 200-301 exam.
It focuses on understanding the difference between on-premises (also called on-prem) and cloud-based network infrastructures — and how they affect the deployment, management, and operation of IT networks.
1. On-Premises Infrastructure
Definition:
On-premises means all the network devices, servers, storage, and applications are physically located inside the organization’s building or data center.
The organization owns, manages, and maintains everything — including the hardware, software, power, cooling, and security.
Characteristics of On-Premises Network
- Ownership
- The company owns all the hardware (switches, routers, firewalls, servers, cables, etc.).
- IT staff are responsible for managing and maintaining all equipment.
- Location
- Devices and servers are located within the company’s physical site (office, branch, or data center).
- Control
- The organization has full control over:
- Network configuration
- Security policies
- Access permissions
- Updates and maintenance
- The organization has full control over:
- Maintenance and Management
- All updates, patches, and troubleshooting must be done by the internal IT team.
- The organization must plan for redundancy, backups, and disaster recovery.
- Costs
- High initial setup costs (buying servers, network gear, licenses, etc.).
- Continuous costs for maintenance, power, and staff.
- Scalability
- Adding new devices or capacity takes time and money.
- Hardware expansion requires physical installation and often downtime.
- Security
- Security is fully managed internally.
- The organization must implement firewalls, intrusion prevention, and physical access control.
Example (IT Context)
A company runs its own internal email server, file storage, and database using servers located in its data center.
All employees access these systems through the internal LAN and WAN managed by the IT team.
Advantages of On-Premises
- Full control of data and configuration.
- Easier to meet strict security or compliance requirements.
- No dependency on Internet connection for local access.
Disadvantages of On-Premises
- High capital cost (hardware, software, infrastructure).
- Requires skilled IT staff for management.
- Harder and slower to scale (grow or shrink capacity).
- Risk of data loss if no proper backups or redundancy.
2. Cloud Infrastructure
Definition:
Cloud infrastructure means IT resources (such as servers, storage, applications, and even network functions) are hosted and managed by a third-party provider (like Amazon AWS, Microsoft Azure, or Google Cloud).
The organization rents these resources over the Internet instead of owning physical equipment.
Characteristics of Cloud Network
- Ownership
- The cloud service provider (CSP) owns and maintains the hardware and software.
- The customer only pays for what they use.
- Location
- Data and systems are hosted in the provider’s data centers, not inside the company’s building.
- Control
- The provider controls the infrastructure.
- The customer controls only the services and configurations through a web portal or API.
- Maintenance and Management
- The provider manages hardware upgrades, replacements, and basic security.
- The customer manages applications, user access, and sometimes virtual networks.
- Costs
- No upfront hardware cost.
- Pay-as-you-go or subscription-based billing model.
- Scalability
- Very easy to scale up or down instantly.
- Resources (CPU, RAM, storage) can be increased through the management console.
- Security
- Cloud providers offer strong security controls, but the organization must manage user access and data protection.
- Security is a shared responsibility:
- The provider secures the cloud infrastructure.
- The customer secures data and access.
Cloud Service Models (Important for CCNA)
There are three main cloud service models you must understand:
| Model | Description | Example Use in Networking |
|---|---|---|
| IaaS (Infrastructure as a Service) | Provides virtualized computing resources over the Internet — such as virtual machines, virtual networks, and storage. | Cisco routers or firewalls running as virtual appliances in a cloud network. |
| PaaS (Platform as a Service) | Provides a development and deployment environment. The provider manages the servers and OS. | Hosting internal business applications or network monitoring tools. |
| SaaS (Software as a Service) | Provides access to software over the Internet — users do not manage any infrastructure. | Cloud-based collaboration tools, email, or monitoring dashboards like Cisco Meraki Dashboard. |
Types of Cloud Deployment Models
| Cloud Type | Description | Example Use |
|---|---|---|
| Public Cloud | Shared cloud environment managed by a provider. Multiple customers share resources. | Using AWS or Azure to host virtual routers or servers. |
| Private Cloud | Dedicated cloud infrastructure for a single organization. | Company’s internal virtual data center. |
| Hybrid Cloud | Combination of on-premises and cloud infrastructure that work together. | Running internal servers on-prem but storing backups or applications in the cloud. |
Advantages of Cloud
- Low initial cost.
- Scalable and flexible – resources can be added instantly.
- Fast deployment – no need to buy and install hardware.
- Provider manages hardware and maintenance.
- High availability (data replicated across multiple locations).
Disadvantages of Cloud
- Less control over hardware and underlying systems.
- Internet dependency – if the Internet is down, access is affected.
- Possible security and compliance concerns.
- Ongoing subscription cost.
3. Hybrid Infrastructure (On-Premises + Cloud)
Most organizations today use a hybrid model, which combines both:
- On-premises network for sensitive or legacy systems.
- Cloud for scalable applications, backup, and remote access.
Example in IT Context:
A company keeps its main database on-prem for security, but hosts its web servers on the cloud for better scalability and availability.
4. Comparison Table
| Feature | On-Premises | Cloud |
|---|---|---|
| Ownership | Owned by organization | Owned by cloud provider |
| Location | Company’s site | Provider’s data center |
| Cost Type | Capital Expense (CapEx) | Operational Expense (OpEx) |
| Scalability | Limited, manual | High, automatic |
| Maintenance | Handled by IT staff | Handled by provider |
| Deployment Speed | Slow | Fast |
| Control Level | Full | Partial |
| Internet Dependence | Not required (for internal use) | Required |
| Security Responsibility | Entirely organization’s | Shared between provider and customer |
5. Key Terms to Remember for Exam
- On-premises – locally hosted and fully controlled by the organization.
- Cloud computing – resources delivered over the Internet.
- IaaS, PaaS, SaaS – three cloud service models.
- Public, Private, Hybrid cloud – three cloud deployment types.
- CapEx vs. OpEx – capital vs. operational expenditure.
- Shared responsibility model – both provider and customer play a role in security.
✅ Summary for CCNA Exam:
- Understand the differences between on-prem and cloud architectures.
- Know the benefits and limitations of each.
- Be able to explain cloud models (IaaS, PaaS, SaaS) and deployment types (Public, Private, Hybrid).
- Recognize how networking concepts apply to both (e.g., virtual routers, cloud firewalls, VPNs to connect on-prem to cloud).
