What is a Ebgp?

Summary

1. What is the difference between BGP and EBGP:

External Border Gateway Protocol or eBGP is a flavor of Border Gateway Protocol (BGP) used for communication between different autonomous systems (AS). eBGP functions as the protocol responsible for interconnection of networks from different organizations or the Internet.

2. What is the difference between EBGP and OSPF:

While BGP excels with dynamic routing for large networks, OSPF offers more efficient path choice and convergence speed. Border Gateway Protocol, or BGP, and Open Shortest Path First, or OSPF, are two of the most popular, standards-based dynamic routing protocols used around the world.

3. How does EBGP work:

Border Gateway Protocol (BGP) refers to a gateway protocol that enables the internet to exchange routing information between autonomous systems (AS). As networks interact with each other, they need a way to communicate. This is accomplished through peering. BGP makes peering possible.

4. What is EBGP peer:

EBGP peerings are the core component of the BGP protocol on the Internet. EBGP is the exchange of network prefixes between autonomous systems. The following behaviors are different on EBGP sessions when compared to IBGP sessions: Time to Live (TTL) on BGP packets is set to one.

5. Why do we use eBGP:

EBGP Multihop can be used to connect networks across multiple autonomous systems and is an important tool for network administrators who need to connect different networks over long distances.

6. What are the 3 types of routing performed by BGP:

– Routing Information Protocol (RIP)

– Interior Gateway Protocol (IGRP)

– Open Shortest Path First (OSPF)

7. What are the four types of OSPF routers:

– Routers for internal use: Internal routers

– Area Borders Routers

– Autonomous Systems Boundary Routers

– Backbone Routers

8. Do eBGP neighbors need to be directly connected:

Neighbors do not have to be directly connected to each other. Because IBGP peers are not required to be directly connected, IBGP uses the IGP path (the IP next-hop learned from the IGP) to reach an IBGP peer for its peering connection.

9. When using eBGP, how is the best possible route determined:

Prefer the path with the lowest neighbor IP address. If you have two eBGP routers and two links in between then the router ID will be the same. In this case, the neighbor IP address is the tiebreaker.

10. What is BGP routing in a nutshell:

BGP is designed to exchange routing and reachability information between autonomous systems on the Internet. Each BGP speaker, which is called a ‘peer’, exchanges routing information with its neighboring peers in the form of network prefix announcements.

11. Do all routers use BGP:

The answer is yes. BGP is the routing protocol of the Internet. BGP is how all Internet routers route your email and web requests across the Internet. Without BGP, no traffic would flow across the Internet, and the Internet would be useless.