1.2 What is BGP

Question 1

Is BGP a fast routing protocol?

Answer 1

BGP is a Path Vector routing protocol. BGP it’s the slowest routing protocol by design. It uses port TCP 179 as transport.

Question 2

What’s the definition of an Autonomous System (AS)?

Answer 2

Autonomous System (AS) is a group of networks/prefixes in a logical domain under the control of a single entity.

Question 3

Is eBGP routing protocol used inside or outside?

Answer 3

eBGP is an external routing protocol with AD:20

Question 4

Is iBGP routing protocol used inside or outside?

Answer 4

iBGP is an internal routing protocol with AD: 200.

Question 5

What mechanism does BGP use as route loop prevention?

Answer 5

BGP uses AS-Path as a route loop prevention

Question 6

Do you need to be directly connected to establish a BGP neighbor relationship?

Answer 6

BGP does not need to be directly connected to form a neighbor.

iBGP default TTL is 255.
eBGP default TTL is 0, but it can be adjusted via the configuration:

R1 (config-router)#no neighbor X.X.X.X disable-connected-check
R1 (config-router)#neighbor X.X.X.X ebgp-multihop #