How does BGP find the best path?
If there are no specific settings that can affect the outcome, BGP Best Path Selection Algorithm determines the best route by selecting the shortest path to the destination. An Autonomous System is a single network or a set of networks and routers, which are under the control of one administrative entity.
Can BGP be used as IGP?
If all routers in an AS are BGP speakers, no interaction is necessary between BGP and an IGP. In such cases, all routers in the AS already have full knowledge of all BGP routes. The IGP is then only used for routing within the AS, and no BGP routes are imported into the IGP.
What is the difference between BGP and IGP routing?
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.
What does Border Gateway Protocol ( BGP ) do?
Border Gateway Protocol (BGP) is an interdomain routing protocol designed to provide loop-free routing between separate routing domains that contain independent routing policies (autonomous systems).
When do you need a BGP in a WAN?
The other reason you see BGP in Enterprise networks is MPLS WAN’s. However, most MPLS providers do offer IGP’s also, and even if they refused an overlay such as DMVPN could be used on top of the MPLS to allow an IGP to make WAN routing decisions. Carriers primarily use BGP to direct traffic as BGP is purpose built for this.
How is an interior gateway protocol ( IGP ) used?
An interior gateway protocol (IGP) is a type of protocol used for exchanging routing information between gateways (commonly routers) within an autonomous system (for example, a system of corporate local area networks). This routing information can then be used to route network-layer protocols like IP.