1.外部边界网关协议(EBGP)：
在自治系统之间使用EBGP。它在为两个或多个自治系统提供互连的边缘或边界路由器上使用和实现。它充当负责来自不同组织或Internet的网络互连的协议。
2.内部边界网关协议(IBGP)：
IBGP用于自治系统中。它用于向内部路由器提供信息。它要求同一自治系统中的所有设备形成全网状拓扑，或者路由反射器和联邦之一用于前缀学习。
EBGP和IBGP之间的区别：
| SR.NO | EBGP | IBGP |
|---|---|---|
| 1 | EBGP stands for External Border Gateway Protocol. | IBGP stands for Internal Border Gateway Protocol. |
| 2 | It runs between two BGP routers in different autonomous system. | It runs between two BGP routers in the same autonomous system. |
| 3 | Its default Administrative Distance is 20. | Its default Administrative Distance is 200. |
| 4 | EBGP routes received from an EBGP peer can be advertised to EBGP and IBGP peers. | IBGP routes received from an IBGP peer cannot be advertised to another IBGP peer but can be advertised to an EBGP peer. |
| 5 | It does not require full mesh topology. | It require full mesh topology. |
| 6 | It is used between organization or between organization and Internet Service provider. | It is used within the same organization. |
| 7 | It uses as path for loop prevention. | It uses BGP Split horizon for loop prevention. |
| 8 | It default peers are set with TTL = 1. | It default peers are set with TTL = 255. |
| 9. | In EBGP peers, attributes like local preference are not sent. | In IBGP peers, attributes like local preference are sent. |
| 10. | When route is advertised to EBGP peer, next hop is changed to local router . | When route is advertised to IBGP peer, next hop remains unchanged. |