Router
Definition
A device that directs internet traffic between devices and the internet, acting like a traffic controller to manage data flow effectively.
Use Cases
- Netflix: Connect many internal services across multiple AWS VPCs and regions while controlling how traffic flows between networks. — Uses AWS networking primitives (VPC routing and centralized connectivity patterns such as transit-style routing) to steer traffic between VPCs and shared services, with route propagation and segmentation to control paths. (Improved scalability and operational control of network connectivity as the number of services and environments grew.)
- Spotify: Securely connect cloud workloads to internal systems and manage traffic paths between environments. — Uses cloud virtual networking with route tables and gateways to direct traffic between subnets, shared services, and external connectivity, applying least-privilege network paths. (More predictable connectivity and easier scaling of services without redesigning physical network hardware.)
Provider Equivalents
- AWS: Amazon VPC Router (implicit)
- Azure: Azure Virtual Network routing (system routes) / Virtual network gateway (for VPN/ExpressRoute)
- GCP: Google Cloud VPC routes (implicit) / Cloud Router (dynamic routing for hybrid)
- OCI: OCI Virtual Cloud Network (VCN) routing (route tables) / Dynamic Routing Gateway (DRG)
Frequently Asked Questions
- What's the difference between a router and a switch?
- A switch connects devices within the same local network (LAN) and forwards traffic based on MAC addresses (Layer 2). A router connects different networks (for example, your home network to the internet) and forwards traffic based on IP addresses (Layer 3). In cloud networks, routing is typically handled by virtual routers and route tables, while switching is handled by the provider’s virtual network fabric.
- When should I use a router?
- Use a router whenever you need to connect two or more different networks and control how traffic moves between them—such as connecting a home/office LAN to the internet, connecting multiple subnets, or linking on-premises networks to cloud networks. In cloud, you typically "use routing" by configuring route tables and, for hybrid connectivity, using a VPN/Direct Connect/ExpressRoute-type gateway and (optionally) dynamic routing with BGP.
- How much does a router cost?
- For home/SMB, a physical router is usually a one-time hardware purchase (often tens to a few hundred USD), plus your internet service. In cloud, basic VPC/VNet/VCN routing via route tables is generally included, but you pay for related components like VPN gateways, dedicated connectivity (AWS Direct Connect/Azure ExpressRoute), transit hubs (AWS Transit Gateway), and data transfer/egress. Costs depend mainly on throughput, hours of gateway usage, number of attachments/tunnels, and how much data crosses regions or leaves the cloud.
Category: networking
Difficulty: basic
Related Terms
See Also