When should you choose OSPF over BGP routing protocols?

OSPF (Open Shortest Path First) and BGP (Border Gateway Protocol) are both routing protocols used in computer networking. OSPF is used within an organization's network to find the shortest path between routers, while BGP is used to exchange routing information between different networks on the internet.

- OSPF é usado para roteamento interno dentro de um sistema aut?nomo, otimizado para redes internas de uma organiza??o. - BGP é usado para roteamento entre diferentes sistemas aut?nomos, como na internet, permitindo controle detalhado sobre como o tráfego é encaminhado entre redes.

It's really that simple - when to use BGP: always, when to use OSPF: never. These pros and cons were taken from some dusty 25y old John T. Moy book on OSPF, I guess. When firewalls equipped with dynamic routing simply did not exist and BGP was considered a bull in a china shop for Internet peering only.

Choosing between OSPF (Open Shortest Path First) and BGP (Border Gateway Protocol) depends on various factors such as network size, topology, scalability requirements, and the organization's goals. Here's some guidelines on when to choose OSPF over BGP: - Internal network with multiple routers & switches - When using hierarchical networks - Need fast convergence - Using link-state protocol - Using Equal Cost Multipath (ECMP) routing - When Internet connectivity is small Ultimately, the choice between OSPF and BGP depends on the specific requirements and constraints of the network environment. In many cases, organizations use both protocols in conjunction to address different aspects of their routing needs.

Many colleagues will probably disagree with me, but my answer would be to avoid using OSPF if possible. Unfortunately, this is a protocol with many threats that must be anticipated, such as the discontinuity of area 0 and protection against this phenomenon.

OSPF (Open Shortest Path First) is typically used in scenarios where large, dynamic networks require efficient routing protocols capable of adapting to changing network conditions. It's particularly beneficial in environments where quick convergence and optimal path determination are critical. OSPF's ability to support hierarchical network designs, coupled with its robustness in scaling to large networks, makes it a preferred choice for organizations with complex infrastructures. Additionally, OSPF's link-state routing approach provides detailed information about network topology, enabling routers to make informed routing decisions. Overall, OSPF is a reliable solution for managing the routing needs of expansive, evolving networks.

BGP recommendations: 1. You have a large network that spans across multiple Autonomous Systems (AS) or service providers. 2. You need to exchange routing information with other networks to ensure efficient path selection and prevent recursive routing loops. 3. You want to implement policy-based routing decisions, such as filtering or blocking specific types of traffic. 4. You need to support multihoming, where a single network is connected to multiple ISPs or service providers. 5. You want to use advanced routing features such as route reflectors, confederations, or BGP-based VPNs. In general, BGP is a good choice when you need a highly scalable and flexible routing protocol that can handle complex network topologies and routing policies.

When to use both OSPF and BGP: Complex Networks: OSPF internally for dynamic routing, BGP at edge for inter-domain routing. Redundancy: OSPF for internal redundancy, BGP for external stability. Traffic Engineering: OSPF for intra-domain, BGP for inter-domain traffic control. Multi-homing: BGP for multi-homing, better ISP traffic control. Policy Enforcement: BGP allows granular routing policy control, lacking in OSPF.

Choose OSPF for internal network routing within your organization and BGP for managing connections between autonomous systems, such as internet connectivity or complex routing policies. Consider network size, routing requirements, and administrative overhead when making your decision.