1. Connecting an Enterprise Network to an ISP Network
Comparing the Functions and Uses of EBGP and IBGP
Connecting an Enterprise Network to an ISP Network

2. BGP Neighbors A “BGP neighbor” is also known as a “BGP peer”
TCP connection

3. External BGP Neighbors
A BGP neighbor in a different AS

4. Requirements for EBGP Different AS number Defined neighbors
Reachability

5. Internal BGP Neighbors
A BGP neighbor in same AS
Requirements:
Same AS number
Defined neighbors
Reachability

6. Summary
Every BGP router establishes a neighbor relationship with other BGP neighbors.
An External BGP (EBGP) neighbor relationship is established between the routers in different autonomous systems (AS).
An Internal BGP (IBGP) neighbor relationship is established between routers in the same AS.