注:如无特别说明,同一网段中,IP 地址的主机位为其设备编号,如 R3 的 g0/0 接口若在 192.168.1.0/24
网段,则其 IP 地址为 192.168.1.3/24
,以此类推。此拓扑中 FTPA,PCA,PCB 使用路由器来模拟
X.X.X.X/32
,X 为设备编号根据网段和设备号配置主机号
内部测通
分部OSPF
办事处配置RIP
[r1]bgp 100
[r1-bgp-default]group lsy internal
[r1-bgp-default]peer lsy as 100
[r1-bgp-default]peer 2.2.2.2 group lsy
[r1-bgp-default]peer 3.3.3.3 group lsy
[r1-bgp-default]peer lsy connect-interface lo0
[r1-bgp-default]address-family ipv4
[r1-bgp-default-ipv4]peer lsy enable
[r2]bgp 100
[r2-bgp-default]group lsy internal
[r2-bgp-default]peer lsy as 100
[r2-bgp-default]peer 1.1.1.1 group lsy
[r2-bgp-default]peer 3.3.3.3 group lsy
[r2-bgp-default]peer 10.0.3.4 as 200
[r2-bgp-default]peer lsy connect-interface LoopBack 0
[r2-bgp-default]add ipv4
[r2-bgp-default-ipv4]peer lsy enable
[r2-bgp-default-ipv4]peer 1.1.1.1 next-hop-local
[r2-bgp-default-ipv4]peer 10.0.3.4 enable
[r3]bgp 100
[r3-bgp-default]group lsy internal
[r3-bgp-default]peer lsy as 100
[r3-bgp-default]peer 1.1.1.1 group lsy
[r3-bgp-default]peer 2.2.2.2 group lsy
[r3-bgp-default]peer 10.0.4.5 as 200
[r3-bgp-default]peer lsy con lo0
[r3-bgp-default]add ipv4
[r3-bgp-default-ipv4]peer lsy en
[r3-bgp-default-ipv4]peer 1.1.1.1 next-hop-local
[r3-bgp-default-ipv4]peer 10.0.4.5 enable
分公司
[r4]bgp 200
[r4-bgp-default]group dxy internal
[r4-bgp-default]peer dxy as 200
[r4-bgp-default]peer 5.5.5.5 group dxy
[r4-bgp-default]peer 6.6.6.6 gro dxy
[r4-bgp-default]peer 10.0.3.2 as 100
[r4-bgp-default]peer dxy con lo0
[r4-bgp-default]add ipv4
[r4-bgp-default-ipv4]peer dxy en
[r4-bgp-default-ipv4]peer 6.6.6.6 next-hop-local
[r4-bgp-default-ipv4]peer 10.0.3.2 en
[r5]bgp 200
[r5-bgp-default]group dxy internal
[r5-bgp-default]peer 4.4.4.4 group dxy
[r5-bgp-default]peer 6.6.6.6 group dxy
[r5-bgp-default]peer 10.0.4.3 as 100
[r5-bgp-default]peer dxy con lo0
[r5-bgp-default]add ipv4
[r5-bgp-default-ipv4]peer dxy en
[r5-bgp-default-ipv4]peer 6.6.6.6 next-hop-local
[r5-bgp-default-ipv4]peer 10.0.4.3 en
[r6]bgp 200
[r6-bgp-default]group dxy internal
[r6-bgp-default]peer 4.4.4.4 group dxy
[r6-bgp-default]peer 5.5.5.5 group dxy
[r6-bgp-default]peer dxy as 200
[r6-bgp-default]peer dxy con lo0
[r6-bgp-default]add ipv4
[r6-bgp-default-ipv4]peer dxy enable
[r1-bgp-default-ipv4]net 192.168.0.0 24
[r1-bgp-default-ipv4]net 100.1.0.0 24
[r6-bgp-default-ipv4]net 192.168.1.0 24
[r6-bgp-default-ipv4]net 100.1.1.0 24
[r2]acl basic 2000
[r2-acl-ipv4-basic-2000]rule permit source 100.1.0.0 0.0.0.255
[r2]route-policy b permit node 10
[r2-route-policy-b-10]if ip add acl 2000
[r2-route-policy-b-10]apply as 100
[r2]route-policy b permit node 20
[r2]bgp 100
[r2-bgp-default]add ipv4
[r2-bgp-default-ipv4]peer 10.0.3.4 route-policy b export
[r4]acl ba 2000
[r4-acl-ipv4-basic-2000]rule permit source 100.1.1.0 0.0.0.255
[r4]route-policy b permit node 10
[r4-route-policy-b-10]if ip add acl 2000
[r4-route-policy-b-10]apply as 200
[r4]route-policy b permit node 20
[r4]bgp 200
[r4-bgp-default]add ipv4
[r4-bgp-default-ipv4]peer 10.0.3.2 route-policy b export
[r3]acl ba 2000
[r3-acl-ipv4-basic-2000]rule permit source 192.168.0.0 0.0.0.255
[r3]route-policy a permit node 10
[r3-route-policy-a-10]if ip add acl 2000
[r3-route-policy-a-10]apply as 100
[r3]route-policy a permit node 20
[r3]bgp 100
[r3-bgp-default-ipv4]peer 10.0.4.5 route-policy a export
[r5]acl basic 2000
[r5-acl-ipv4-basic-2000]rule permit source 192.168.1.0 0.0.0.255
[r5-route-policy-a-10]if ip add acl 2000
[r5-route-policy-a-10]apply as 200
[r5]route-policy a permit node 20
[r5]bgp 200
[r5-bgp-default]add ipv4
[r5-bgp-default-ipv4]peer 10.0.4.3 route-policy a export
查看R1和R2的BGP路由表:
下一跳变成一个是因为R2和R5分别从邻居路由器学习到了AS路径更
短的路由,由于BGP防环机制,IBGP从IBGP邻居 学习到的不会传递
给其他IBGP邻居。
默认情况下,引入BGP路由时只会引入EGP路由,引入IBGP路由需要添加参数allow-ibgp
[r2]acl basic 2001
[r2-acl-ipv4-basic-2001]rule permit s 192.168.1.0 0.0.1.255
[r2-acl-ipv4-basic-2001]rule permit source 100.1.0.0 0.0.0.255
[r2-route-policy-zzz-10]if ip add acl 2001
[r2]rip
[r2-rip-1]import-route bgp allow-ibgp route-policy zzz
[r2-bgp-default]add ipv4
[r2-bgp-default-ipv4]import-route rip
[r2]acl basic 2002
[r2-acl-ipv4-basic-2002]rule deny source 100.1.2.0 0.0.0.255
[r2-acl-ipv4-basic-2002]rule permit
[r3]acl basic 2001
[r3-acl-ipv4-basic-2001]rule deny source 100.1.2.0 0.0.0.255
[r3-acl-ipv4-basic-2001]rule permit
[r3-bgp-default]add ipv4
[r3-bgp-default-ipv4]peer 10.0.4.5 route-policy zz export
查看路由6
[r1-ospf-1]silent-interface lo1
[r1-ospf-1]silent-interface lo2
[r6-ospf-1]silent-interface LoopBack 1
[r6-ospf-1]silent-interface LoopBack 2
[r7-rip-1]silent-interface lo0
[r7-rip-1]silent-interface lo1
[r2]rip
[r2-rip-1]silent-interface g0/0
[r2-rip-1]silent-interface g0/1
[r2-rip-1]silent-interface g0/2
[r3]ip as-path 1 permit ^$
[r3]bgp 100
[r3-bgp-default]add ipv4
[r3-bgp-default-ipv4]peer 10.0.4.5 as-path-acl 1 export
[r2]ip as-path 1 permit ^$
[r2]bgp 100
[r2-bgp-default]add ipv4
[r2-bgp-default-ipv4]peer 10.0.3.4 as-path-acl 1 export
发现R1路由表,发现等价路由
[r1]int g0/1
[r1-GigabitEthernet0/1]ospf cost 4
再次查看没有等价路由
BGP 用于自治系统间的动态路由协议