How Does Routing Work?
Dynamic Routing Protocols OSPF, EIGRP, RIPv2, IS-IS, BGP
- OSPF (Open Shortest Path First),
- EIGRP (Enhanced Interior Gateway Routing Protocol),
- RIPv2 (Routing Information Protocol Version 2),
- IS-IS (Intermediate System-to-Intermediate System),
- BGP (Border Gateway Protocol)
There are two main types of dynamic routing protocols: Interior Gateway Protocols (IGP) and Exterior Gateway Protocols (EGP).
IGP is a routing protocol that is used within an autonomous system (AS). Examples of IGP protocols include Routing Information Protocol (RIP), Open Shortest Path First (OSPF), and Intermediate System to Intermediate System (IS-IS). IGP protocols are used to exchange routing information between routers within the same network and are typically used in small to medium-sized networks.
EGP is a routing protocol that is used between different autonomous systems (ASes) on the Internet. The Border Gateway Protocol (BGP) is the most widely used EGP protocol. EGP protocols are used to exchange routing information between different networks and are typically used in large enterprise networks and Internet Service Providers (ISPs).
Both IGP and EGP protocols have their own advantages and disadvantages. IGP protocols are simpler and easier to configure, making them ideal for smaller networks. They are also faster and more efficient at exchanging routing information within the same network. However, they are less suitable for large networks or networks with multiple autonomous systems.
OSPF: OSPF is a link-state routing protocol that uses a hierarchical network structure and calculates the shortest path to a destination based on the cost of links between routers. It supports variable-length subnet masks (VLSMs) and route summarization, and is commonly used in enterprise networks.
EIGRP: EIGRP is a proprietary routing protocol developed by Cisco that uses both distance-vector and link-state routing algorithms. It supports VLSMs, route summarization, and automatic summarization, and is commonly used in enterprise networks.
RIPv2: RIPv2 is a distance-vector routing protocol that uses hop counts as the metric for path selection. It supports VLSMs and route summarization, but can be slow to converge and is generally not recommended for larger networks.
IS-IS: IS-IS is a link-state routing protocol that is commonly used in service provider networks. It uses a hierarchical network structure and calculates the shortest path to a destination based on the cost of links between routers. It supports VLSMs and route summarization.
BGP: BGP is a path-vector routing protocol that is primarily used for inter-domain routing on the internet. It selects the best path to a destination based on a set of attributes, such as the length of the AS path, the origin of the route, and the next-hop IP address.
Overall, the key differences between these routing protocols lie in their routing algorithms, network structures, metrics, and features. The choice of routing protocol depends on the specific requirements and characteristics of the network, such as size, complexity, and traffic patterns.