BGP
Definition
Border Gateway Protocol - routing protocol used to exchange routing information between different networks on the internet.
Use Cases
- Cloudflare: Anycast routing to steer user traffic to the nearest/healthiest data center and to mitigate DDoS attacks by absorbing traffic across a global network. — Cloudflare advertises IP prefixes from many global points of presence using BGP (anycast). They adjust routing announcements and traffic engineering policies to influence how the internet reaches their services. (Lower latency for end users through nearest-site routing and improved resilience by distributing traffic across many locations.)
- Netflix: Delivering video efficiently by placing Open Connect caching appliances inside ISP networks and directing users to nearby caches. — Netflix works with ISPs to deploy Open Connect appliances and uses BGP-based routing/peering practices so subscriber traffic reaches local caches rather than traversing long-haul transit paths. (Reduced backbone/transit usage for ISPs and improved streaming performance and reliability for viewers.)
- Google: Hybrid connectivity where enterprises connect on-premises networks to Google Cloud with dynamic route exchange and failover. — Customers use Dedicated Interconnect or Partner Interconnect with BGP sessions to exchange routes; Cloud Router provides the managed BGP control plane for dynamic routing between VPC networks and on-premises. (Simpler operations versus static routes, faster failover, and scalable connectivity as networks grow or change.)
Provider Equivalents
- AWS: AWS Direct Connect (BGP for routing over private connectivity)
- Azure: Azure ExpressRoute (BGP for route exchange between on-premises and Azure)
- GCP: Cloud Interconnect (BGP for dynamic routing with on-premises) and Cloud Router (managed BGP control plane)
- OCI: OCI FastConnect (BGP for private connectivity) and Dynamic Routing Gateway (DRG) (BGP with on-premises and between networks)
Frequently Asked Questions
- What's the difference between BGP and OSPF?
- BGP is mainly used to exchange routes between different organizations or networks (inter-domain routing), like between an ISP and a cloud provider. OSPF is mainly used inside a single organization’s network (intra-domain routing) to route within a campus or data center. In practice, many companies use OSPF internally and BGP at the edge to connect to ISPs and clouds.
- When should I use BGP?
- Use BGP when you need dynamic routing between separate networks, especially for hybrid cloud connectivity (on-prem to cloud), multi-site WANs, or multi-homing to more than one ISP/provider for redundancy. It’s also useful when you want automatic failover and scalable route management instead of maintaining many static routes.
- How much does BGP cost?
- BGP itself is a protocol and has no licensing cost. Costs come from what you run it on and where: routers/firewalls that support BGP, managed cloud routing features (if applicable), and connectivity charges such as dedicated circuits (e.g., Direct Connect/ExpressRoute/Interconnect/FastConnect), VPN gateways, data transfer/egress, and potentially additional ports or attachments. Pricing varies by provider, region, bandwidth, and traffic volume.
Category: networking
Difficulty: advanced
Related Terms
See Also