- Differentiate between Open Shortest Path First (OSPF) and Border Gateway Protocol (BGP). …
- Differentiate between hard reset and soft reset in the context of BGP. …
- What do the various BGP Path Attributes mean? …
- What do you understand about communities in the context of BGP?
BGP- Border Gateway Protocol is the postal service of the Internet. The postal service processes a letter if someone places it in the mailbox and makes sure that it is sent to its intended destination in the best efficient manner. BGP takes charge of analyzing all the possible paths to a data set that has been sent over the internet and selects the best one through which it could be sent. In short, BGP is the protocol that allows data to be routed across the internet.Â
There are still a number of questions about the primary purpose of BGP. In this article, we will address the top BGP interview questions.
BGP Interview Questions and Answers Part 1
Most Commonly Asked BGP Interview Questions
Frequently requested BGP questions, such as scenario-based BGP interview questions and BGP troubleshooting interview questions and answers, have been addressed in this blog.
BGP Interview Questions and Answers for Freshers
Border Gateway Protocol (BGP) is a protocol that allows two networks to communicate with one other. BGP is a standardized outside gateway protocol that allows autonomous systems (AS) on the Internet to share routing and reachability information. A route vector protocol is what the protocol is called. The Border Gateway Protocol is engaged in fundamental routing choices and determines routing decisions depending on pathways, network regulations, or rule sets a network administrator provides.
Within an autonomous system, BGP may be utilized for routing. Interior Border Gateway Protocol, often known as Internal BGP or iBGP, is used in this application. The protocols Internet implementation, on the other hand, is known as Exterior Border Gateway Protocol, External BGP, or eBGP.
What is the difference between the hard reset and soft reset in BGP? In case of hard reset the local router brings down the neighborship, brings down the underlying TCP connection and all the BGP table entries learned from that neighbor are removed. #clear ip bgp * command is used for hard reset. In case of a soft reset, the router does not bring down the BGP neighborship or the underlying TCP connection. However, the local router resends outgoing Updates and reprocesses incoming Updates adjusting the BGP table based on the current configuration. #clear ip bgp * soft command is used for soft reset.
What is Recursive Lookup? The router looks up the BGP route and the next hop to reach a destination in the remote AS. Then the router looks up the route to reach the next hop. In this way router has to perform lookup twice to reach to a destination, this process is called recursive lookup.
Explain BGP Path Attributes? BGP supports a wide variety of Path Attributes. BGP use these path attributes to examine the competing BGP paths (routes) in the BGP table to choose the best path(route). 1. Next Hop – It lists the next-hop IP address used to reach a prefix. If Next hop is reachable? If no route to reach Next Hop, the router cannot use this route.
Explain BGP MED? The purpose of MED is to influence how other autonomous systems enter into your AS to reach a certain prefix. BGP MED is an attribute which is not propagated throughout the whole network but just to adjacent AS. The lower the MED the more the path will be preferred.
What is route reflector and why it is required? In BGP, route learned from an iBGP neighbor will not be advertised to another iBGP neighbor. To overcome this situation route reflector is used. It acts as a route reflector server and makes IBGP neighbors as route reflector clients enabling route advertisements between them.
What is the port number used by the Border Gateway Protocol?
The Border Gateway Protocol uses the Transmission Control protocol post number 179.
FAQ
Which algorithm is used in BGP?
How many types of BGP are there?
What is BGP protocol interview questions and answers?
- Weight.
- Local Preference (highest local value will be preferred, the default value is 100)
- Originate.
- AS path length.
- Origin code.
- Multi-Exit Discriminator (MED)
- eBGP path over iBGP path.
- Shortest IGP path to BGP next-hop.
