BGP小综合

IP地址分化：

172.16.0.0/16

172.16.0.0/18 --- 备份

172.16.64.0/18   ---- 骨干
172.16.64.0/30   23网段
172.16.64.4/30      34
172.16.64.8/30      47
172.16.64.12/30    67
172.16.64.16/30    56
172.16.64.20/30    25

l0
172.16.128.0/18  --- 建邻环回
172.16.128.6/32   R2
172.16.128.1/32   R3
172.16.128.2/32   R4
172.16.128.3/32   R5
172.16.128.4/32   R6
172.16.128.5/32   R7

l1
172.16.192.0/18  --- 用户     
172.16.192.0/24    R2
172.16.193.0/24    R3
172.16.194.0/24    R4
172.16.195.0/24    R5
172.16.196.0/24    R6
172.16.197.0/24    R7

 

 地址配好后，做ospf配置：

eg：

[r2]ospf 1 router-id 2.2.2.2

[r2-ospf-1]area 0

[r2-ospf-1-area-0.0.0.0]network 172.16.0.0 0.0.255.255

配置完后，打开路由表会发现，划分给用户的网段的掩码变成了32位，这时需要将其改回24位，在每个路由器上进入环回1接口敲ospf network-type broadcast

eg：[r4-LoopBack1]ospf network-type broadcast

下一步开始bgp建邻：

先r1和r2，r7和r8

[r1]bgp 1
		
[r1-bgp]peer 12.1.1.2 as-number 2


[r2]bgp 64512
	
[r2-bgp]confederation id 2
	
[r2-bgp]peer 12.1.1.1 as-number 1


[r8]bgp 3
	
[r8-bgp]peer 78.1.1.1 as-number 2


[r7]bgp 64513
	
[r7-bgp]confederation id 2
	
[r7-bgp]peer 78.1.1.2 as-number 3

r2、r3、r4使用联邦，虚拟号64512

[r2]bgp 64512

[r2-bgp]peer 172.16.128.1 as-number 64512

[r2-bgp]peer 172.16.128.1 connect-interface LoopBack 0

[r2-bgp]peer 172.16.128.1 next-hop-local



[r3]bgp 64512
	
[r3-bgp]confederation id 2
	
[r3-bgp]peer 172.16.128.6 as-number 64512
	
[r3-bgp]peer 172.16.128.6 connect-interface LoopBack 0

[r3-bgp]peer 172.16.128.2 as-number 64512
	
[r3-bgp]peer 172.16.128.2 connect-interface LoopBack 0


[r4]bgp 64512
	
[r4-bgp]confederation id 2
	
[r4-bgp]peer 172.16.128.1 as-number 64512

[r4-bgp]peer 172.16.128.1 connect-interface LoopBack 0

r5、r6、r7建立联邦，虚拟号64513

[r5]bgp 64513
	
[r5-bgp]confederation id 2

[r5-bgp]peer 172.16.128.4 as-number 64513

[r5-bgp]peer 172.16.128.4 connect-interface LoopBack 0



[r6]bgp 64513

[r6-bgp]confederation id 2

[r6-bgp]peer 172.16.128.3 as-number 64513

[r6-bgp]peer 172.16.128.3 connect-interface LoopBack 0

[r6-bgp]peer 172.16.128.5 as-number 64513
	
[r6-bgp]peer 172.16.128.5 connect-interface LoopBack 0



[r7]bgp 64513
	
[r7-bgp]confederation id 2
	
[r7-bgp]peer 172.16.128.4 as-number 64513
	
[r7-bgp]peer 172.16.128.4 connect-interface LoopBack 0

[r7-bgp]peer 172.16.128.4 next-hop-local

区域64512与区域64513建邻

[r2]bgp 64512
	
[r2-bgp]confederation peer-as 64513
	
[r2-bgp]peer 172.16.128.3 as-number 64513

[r2-bgp]peer 172.16.128.3 ebgp-max-hop 2

[r2-bgp]peer 172.16.128.3 connect-interface LoopBack 0

[r2-bgp]peer 172.16.128.3 next-hop-local 


[r5]bgp 64513
	
[r5-bgp]confederation peer-as 64512
	
[r5-bgp]peer 172.16.128.6 as-number 64512
	
[r5-bgp]peer 172.16.128.6 ebgp-max-hop 2
	
[r5-bgp]peer 172.16.128.6 connect-interface LoopBack 0


[r4]bgp 64512
	
[r4-bgp]confederation peer-as 64513
	
[r4-bgp]peer 172.16.128.5 as-number 64513
	
[r4-bgp]peer 172.16.128.5 ebgp-max-hop 2
	
[r4-bgp]peer 172.16.128.5 connect-interface LoopBack 0


[r7]bgp 64513
	
[r7-bgp]confederation peer-as 64512

[r7-bgp]peer 172.16.128.2 as-number 64512
	
[r7-bgp]peer 172.16.128.2 ebgp-max-hop 2

[r7-bgp]peer 172.16.128.2 connect-interface LoopBack 0

[r7-bgp]peer 172.16.128.2 next-hop-local

给r3和r6建立路由反射器

[r3]bgp 64512
	
[r3-bgp]peer 172.16.128.2 reflect-client


[r6]bgp 64513

[r6-bgp]peer 172.16.128.5 reflect-client

现在全区域都已建邻，接下来进行宣告，首先宣告r1和r8的环回

eg：[r1]bgp 1

        [r1-bgp]network 11.1.1.0 24

在r2和r7上配置静态路由172.16.192.0 18 NULL 0，防止路由黑洞

eg：[r7]ip route-static 172.16.192.0 18 NULL 0

最后在r2的bgp上宣告172.16.192.0 18的用户网段，再查看每个路由器的bgp表确认无误后，即可实现全网可达

eg：

测试：