What is IGP and BGP?
IGP is used to establish and distribute routing information to routers within Autonomous System (AS), the most common routing protocols within this category are RIP (Routing Information Protocol) and OSPF (Open Shortest Path First) [2]. BGP is used to route traffic between ASs within the internet.
Can BGP be used as IGP?
BGP is a routing protocol, but it is not an IGP but an EGP. So it does not handle routes within the same AS, it is only for exchanging routing information between different ASn. Theoretically, that may be done with static routing, but in practice, a different routing protocol, an IGP like OSPF or EIGRP is used.
Can BGP work without IGP?
No IGP was used. Before a BGP route is advertised and added to the routing table, this route must be known via an IGP. For the case of AS65000, no IGP is used, only pure iBGP peering hence BGP synchronization will stop bgp speaker from adding routes learned by its iBGP peer to its routing table.
Is OSPF an IGP or EGP?
Companies, organizations, and even service providers use an IGP on their internal networks. IGPs include RIP, EIGRP, OSPF, and IS-IS. Exterior Gateway Protocols (EGP): Used for routing between autonomous systems.
Why we use BGP instead of IGP?
The gist of it is that IGPs are built to operate within an autonomous system and BGP is built to operate between autonomous systems. The key difference is in the nature of intra-AS vs. The goal is to get a holistic view of the autonomous system and the need for routing policy, while there, isn’t great.
What is IGP routing protocol?
An interior gateway protocol (IGP) is a dynamic route update protocol used between routers that run on TCP/IP hosts within a single autonomous system. The routers use this protocol to exchange information about IP routes.
Why is IGP required for BGP?
As we know, IGP stands for Interior Gateway Protocol and represents a group of routing protocols that run within a single administrative domain. IGP selects the shortest path between the two nodes based on distance. The distance here is a sum of metrics of all the links that belong to a given path.
Can OSPF replace BGP?
BGP would peer with the neighbor and OSPF would synchronize a full topology from its neighbors. You would then configure OSPF to redistribute routes learned from BGP into the OSPF topology and vice versa. Static routes typically need to be redistributed.
Do home routers use BGP?
The short answer to this question is NO. You do not need to run BGP on your home or small business router. All Internet Service Providers (ISPs) that have multiple connections to the Internet use BGP to communicate with those other providers.
How does IGP routing work?
What are the two categories of IGP protocols?
An interior gateway protocols (IGP) is used to route the traffic within each separate network of an autonomous system (AS). There are two types of IGP: distance vector routing and link state routing.
What’s the difference between internal BGP and external BGP?
This is what internal BGP (iBGP) is for. The “regular” BGP is thus external BGP (eBGP). When I say all the BGP routers, I really do mean all of them: if your network has 100 BGP routers, each of those needs to maintain iBGP sessions with the other 99. Well, unless you use route reflectors, but that’s a story for another day.
What’s the difference between OSPF and BGP in Cisco?
With OSPF being an IGP and BGP being an EGP suggests an obvious division of labor: OSPF handles the internal routing, BGP the routing towards external destinations. However, it’s not that simple. Yes, OSPF is in charge of internal routing. These routes show up as “O” routes in the output of “show ip route” on a Cisco router.
Which is the most widely used IGP protocol?
As such, Cisco created its own Interior Gateway Routing Protocol (IGRP) and then an enhanced version aptly named Enhanced IGRP (EIGRP). However, the most widely used IGP is OSPF: Open Shortest Path First.
Why do BGP routers need to talk to each other?
However, it would be a bit embarrassing if all the BGP routers in the network would be telling their external neighbors completely different things. So all the BGP routers in the network need to talk to each other in order to tell a consistent story to external networks. This is what internal BGP (iBGP) is for.