How does BGP choose 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..
What is BGP protocol and how it works?
“Border Gateway Protocol (BGP) is a standardized exterior gateway protocol designed to exchange routing and reachability information between autonomous systems (AS) on the Internet. The protocol is often classified as a path vector protocol but is sometimes also classed as a distance-vector routing protocol.”
What is MED value in BGP?
MED is an optional nontransitive attribute. MED is a hint to external neighbors about the preferred path into an autonomous system (AS) that has multiple entry points. The MED is also known as the external metric of a route. A lower MED value is preferred over a higher value.
How does BGP 4 Work?
How does BGP4 work? Unlike the majority of routing protocols, BGP4 is a connection-oriented protocol. When BGP4 is initiated on a router, it establishes a Transmission Control Protocol (TCP) connection with its neighboring router(s). Using this TCP connection, the router exchanges a complete copy of its routing table.
Can BGP do load balancing?
By default, Border Gateway Protocol (BGP) selects only a single best path and does not perform load balancing.
What are the BGP message types?
BGP makes use of four different message types to perform its function namely: OPEN, UPDATE, KEEPALIVE, and NOTIFICATION. Before we consider these message types, we must look at the BGP message header that is present before all these message types and that indicates the type of message contained in the BGP packet.
How do I configure BGP?
To configure the BGP peer sessions:Configure the interfaces to Peers A, B, C, and D. … Set the autonomous system (AS) number. … Create the BGP group, and add the external neighbor addresses. … Specify the autonomous system (AS) number of the external AS. … Add Peer D, and set the AS number at the individual neighbor level.More items…
What metric does BGP use?
The BGP MED attribute, commonly referred to as the BGP metric, provides a means to convey to a neighboring Autonomous System (AS) a preferred entry point into the local AS. BGP MED is a non-transitive optional attribute and thus the receiving AS cannot propagate it across its AS borders.
What protocol does BGP use?
TCPAmong routing protocols, BGP is unique in using TCP as its transport protocol. When BGP runs between two peers in the same autonomous system (AS), it is referred to as Internal BGP (i-BGP or Interior Border Gateway Protocol).