實驗拓撲

實驗要求：

使用兩種方式建立不同AS號的BGP鄰居，不同AS號路由器之間建立的鄰居稱為EBGP鄰居

實驗目的：

熟悉使用物理口和環回口建立鄰居的方式

IP地址規劃：

路由器	接口	IP地址
AR1	G0/0/0	12.1.1.1/24
AR1	Loopback 0	1.1.1.1/24
AR2	G0/0/0	12.1.1.2/24
AR2	G0/0/1	23.1.1.2/24
AR2	Loopback 0	2.2.2.2/24
AR3	G0/0/1	23.1.1.3/24
AR3	Loopback 0	3.3.3.3/24

實驗配置：

物理接口方式：

AR1:
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sys R1
[R1]un in en 
Info: Information center is disabled.
[R1]int g 0/0/0
[R1-GigabitEthernet0/0/0]ip add 12.1.1.1 24
[R1-GigabitEthernet0/0/0]int loo0
[R1-LoopBack0]ip add 1.1.1.1 24
[R1-LoopBack0]bgp 10
[R1-bgp]peer 12.1.1.2 as 20
[R1-bgp]network 12.1.1.0 24
[R1-bgp]network 1.1.1.0 24

AR2:
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sys R2
[R2]un in en 
Info: Information center is disabled.
[R2]int g 0/0/1
[R2-GigabitEthernet0/0/1]ip add 12.1.1.2 24
[R2-GigabitEthernet0/0/1]int g 0/0/0
[R2-GigabitEthernet0/0/0]ip add 23.1.1.2 24
[R2-GigabitEthernet0/0/0]int loo0
[R2-LoopBack0]ip add 2.2.2.2 24
[R2-LoopBack0]bgp 20
[R2-bgp]peer 12.1.1.1 as 10
[R2-bgp]peer 23.1.1.3 as 30
[R2-bgp]net 12.1.1.0 24
[R2-bgp]net 23.1.1.0 24
[R2-bgp]net 2.2.2.0 24

AR3:
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sys R3
[R3]un in en 
Info: Information center is disabled.
[R3]int g 0/0/1
[R3-GigabitEthernet0/0/1]ip add 23.1.1.3 24
[R3-GigabitEthernet0/0/1]int loo0
[R3-LoopBack0]ip add 3.3.3.3 24
[R3-LoopBack0]bgp 30
[R3-bgp]peer 23.1.1.2 as 20
[R3-bgp]net 23.1.1.0 24
[R3-bgp]net 3.3.3.0 24

環回口方式：

重啟路由器，恢復初始配置

AR1:
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sys R1
[R1]un in en 
[R1]ip route-static 2.2.2.0 24 12.1.1.2
Info: Information center is disabled.
[R1]int g 0/0/0
[R1-GigabitEthernet0/0/0]ip add 12.1.1.1 24
[R1-GigabitEthernet0/0/0]int loo0
[R1-LoopBack0]ip add 1.1.1.1 24
[R1-LoopBack0]bgp 10
[R1-bgp]peer 2.2.2.2 as-number 20
[R1-bgp]peer 2.2.2.2 connect-interface LoopBack 0
[R1-bgp]peer 2.2.2.2 ebgp-max-hop
[R1-bgp]network 12.1.1.0 24
[R1-bgp]network 1.1.1.0 24

AR2:
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sys R2
[R2]un in en 
Info: Information center is disabled.
[R2]ip route-static 1.1.1.0 24 12.1.1.1
[R2]ip route-static 3.3.3.0 24 23.1.1.3
[R2]int g 0/0/1
[R2-GigabitEthernet0/0/1]ip add 12.1.1.2 24
[R2-GigabitEthernet0/0/1]int g 0/0/0
[R2-GigabitEthernet0/0/0]ip add 23.1.1.2 24
[R2-GigabitEthernet0/0/0]int loo0
[R2-LoopBack0]ip add 2.2.2.2 24
[R2-LoopBack0]bgp 20
[R2-bgp]peer 1.1.1.1 as-number 10
[R2-bgp]peer 1.1.1.1 connect-interface LoopBack 0
[R2-bgp]peer 1.1.1.1 ebgp-max-hop
[R2-bgp]peer 3.3.3.3 as-number 30
[R2-bgp]peer 3.3.3.3 connect-interface LoopBack 0
[R2-bgp]peer 3.3.3.3 ebgp-max-hop
[R2-bgp]net 2.2.2.0 24
[R2-bgp]net 23.1.1.0 24
[R2-bgp]net 12.1.1.0 24

AR3:
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sys R3
[R3]un in en 
Info: Information center is disabled.
[R3]ip route-static 2.2.2.0 24 23.1.1.2
[R3]int g 0/0/1
[R3-GigabitEthernet0/0/1]ip add 23.1.1.3 24
[R3-GigabitEthernet0/0/1]int loo0
[R3-LoopBack0]ip add 3.3.3.3 24
[R3-LoopBack0]bgp 30
[R3-bgp]peer 2.2.2.2 as-number 20
[R3-bgp]peer 2.2.2.2 connect-interface LoopBack 0
[R3-bgp]peer 2.2.2.2 ebgp-max-hop
[R3-bgp]net 23.1.1.0 24
[R3-bgp]net 3.3.3.0 24

驗證：

通過display bgp peer命令查看BGP鄰居關系，以AR2為例，可以看到狀態為Established，證明EBGP鄰居已經建立完成。

通過display bgp routing-table查看BGP路由情況，可以看到已經學習到了其他區域發送過來的路由條目。

注意事項：

無

實驗結論：

EBGP既可以通過物理口建立鄰居，也可以通過環回口建立鄰居