哈喽，大家好！我是艺博东 ，是一个思科出身、专注于华为的网工；好了，话不多说，我们直接进入正题。
文章目录
由于特殊原因，所以把“N”字母替换为“#”符号。
一、无 RR 的拓扑
二、无 RR 的简单配置与测试
2.1 底层配置
AR1
[Huawei]sysname AR1
[AR1]int g0/0/0
[AR1-GigabitEthernet0/0/0]ip address 10.1.13.1 24
[AR1-GigabitEthernet0/0/0]int l0
[AR1-LoopBack0]ip address 1.1.1.1 32
AR2
[Huawei]sysname AR2
[AR2]int g0/0/0
[AR2-GigabitEthernet0/0/0]ip address 10.1.23.2 24
[AR2-GigabitEthernet0/0/0]int l0
[AR2-LoopBack0]ip address 2.2.2.2 32
AR3
[Huawei]sysname AR3
[AR3]int g0/0/0
[AR3-GigabitEthernet0/0/0]ip address 10.1.13.3 24
[AR3-GigabitEthernet0/0/0]int g0/0/1
[AR3-GigabitEthernet0/0/1]ip address 10.1.23.3 24
[AR3-GigabitEthernet0/0/1]int g0/0/2
[AR3-GigabitEthernet0/0/2]ip address 10.1.34.3 24
[AR3-GigabitEthernet0/0/2]int l0
[AR3-LoopBack0]ip address 3.3.3.3 32
[AR3-LoopBack0]q
[AR3]rip
[AR3-rip-1]v 2
[AR3-rip-1]network 10.0.0.0
[AR3-rip-1]network 3.0.0.0
AR4
[Huawei]sysname AR4
[AR4]int g0/0/0
[AR4-GigabitEthernet0/0/0]ip address 10.1.34.4 24
[AR4-GigabitEthernet0/0/0]int g0/0/1
[AR4-GigabitEthernet0/0/1]ip address 10.1.45.4 24
[AR4-GigabitEthernet0/0/1]int l0
[AR4-LoopBack0]ip address 4.4.4.4 32
[AR4-LoopBack0]q
[AR4]rip
[AR4-rip-1]v 2
[AR4-rip-1]network 10.0.0.0
[AR4-rip-1]network 4.0.0.0
AR5
[Huawei]sysname AR5
[AR5]int g0/0/0
[AR5-GigabitEthernet0/0/0]ip address 10.1.45.5 24
[AR5-GigabitEthernet0/0/0]int g0/0/1
[AR5-GigabitEthernet0/0/1]ip address 10.1.56.5 24
[AR5-GigabitEthernet0/0/1]int l0
[AR5-LoopBack0]ip address 5.5.5.5 32
[AR5-LoopBack0]q
[AR5]rip
[AR5-rip-1]v 2
[AR5-rip-1]undo summary
[AR5-rip-1]network 10.0.0.0
[AR5-rip-1]network 5.0.0.0
[AR5-rip-1]q
[AR5]int g0/0/1
[AR5-GigabitEthernet0/0/1]undo rip output
[AR5-GigabitEthernet0/0/1]undo rip input
AR6、AR7、AR8、AR9、AR10底层配置类似
2.2 MPLS LDP
AR3
[AR3]mpls lsr-id 3.3.3.3
[AR3]mpls
[AR3-mpls]mpls ldp
[AR3-mpls-ldp]int g0/0/2
[AR3-GigabitEthernet0/0/2]mpls
[AR3-GigabitEthernet0/0/2]mpls ldp
AR4
[AR4]mpls lsr-id 4.4.4.4
[AR4]mpls
[AR4-mpls]mpls ldp
[AR4-mpls-ldp]int g0/0/0
[AR4-GigabitEthernet0/0/0]mpls
[AR4-GigabitEthernet0/0/0]mpls ldp
[AR4-GigabitEthernet0/0/0]int g0/0/1
[AR4-GigabitEthernet0/0/1]mpls
[AR4-GigabitEthernet0/0/1]mpls ldp
AR5
[AR5]mpls lsr-id 5.5.5.5
[AR5]mpls
[AR5-mpls]mpls ldp
[AR5-mpls-ldp]int g0/0/0
[AR5-GigabitEthernet0/0/0]mpls
[AR5-GigabitEthernet0/0/0]mpls ldp
[AR5-GigabitEthernet0/0/0]int g0/0/1
[AR5-GigabitEthernet0/0/1]mpls
2.4 AR3和AR5建立MP-IBGP，AR6和AR8建立MP-IBGP；AR5和AR6建立MP-EBGP；AR3和AR8EBGP VP#v4 邻居关系；配置标签能力。
AR3
[AR3]bgp 10
[AR3-bgp]peer 5.5.5.5 as-number 10
[AR3-bgp]peer 5.5.5.5 connect-interface LoopBack0
[AR3-bgp]peer 8.8.8.8 as-number 20
[AR3-bgp]peer 8.8.8.8 ebgp-max-hop 66
[AR3-bgp]peer 8.8.8.8 connect-interface LoopBack0
[AR3-bgp]ipv4-family vpnv4
[AR3-bgp-af-vpnv4]peer 8.8.8.8 enable
AR5
[AR5]route-policy asbr permit node 10
[AR5-route-policy]apply mpls-label
[AR5-route-policy]q
[AR5]bgp 10
[AR5-bgp]peer 3.3.3.3 as-number 10
[AR5-bgp]peer 3.3.3.3 connect-interface LoopBack0
[AR5-bgp]peer 10.1.56.6 as-number 20
[AR5-bgp]network 3.3.3.3 255.255.255.255
[AR5-bgp]peer 10.1.56.6 route-policy asbr export
[AR5-bgp]peer 10.1.56.6 label-route-capability
[AR5-bgp]q
[AR5]mpls
[AR5-mpls]lsp-trigger bgp-label-route //用来配置LDP为带标签的公网BGP路由分标签的能力
[AR5-mpls]quit
[AR5]rip
[AR5-rip-1]import-route bgp
AR6
[AR6]route-policy asbr permit node 10
[AR6-route-policy]apply mpls-label
[AR6-route-policy]q
[AR6]bgp 20
[AR6-bgp]peer 8.8.8.8 as-number 20
[AR6-bgp]peer 8.8.8.8 connect-interface LoopBack0
[AR6-bgp]peer 10.1.56.5 as-number 10
[AR6-bgp]network 8.8.8.8 255.255.255.255
[AR6-bgp]peer 10.1.56.5 route-policy asbr export
[AR6-bgp]peer 10.1.56.5 label-route-capability
[AR6-bgp]q
[AR6]mpls
[AR6-mpls]lsp-trigger bgp-label-route
[AR6-mpls]quit
[AR6]rip
[AR6-rip-1]import-route bgp
AR8
[AR8]bgp 20
[AR8-bgp]peer 3.3.3.3 as-number 10
[AR8-bgp]peer 3.3.3.3 ebgp-max-hop 66
[AR8-bgp]peer 3.3.3.3 connect-interface LoopBack0
[AR8-bgp]peer 6.6.6.6 as-number 20
[AR8-bgp]peer 6.6.6.6 connect-interface LoopBack0
[AR8-bgp]ipv4-family vpnv4
[AR8-bgp-af-vpnv4]peer 3.3.3.3 enable
2.5 测试
[AR3]display bgp peer
[AR6]display bgp peer
[AR8]display mpls lsp
AR8已经有AR3的3.3.3.3的标签了。
[AR8]ping -a 8.8.8.8 3.3.3.3
2.6 MPLS VP#业务接入
配置好公网之后，接下来是配置公司B和公司D，让他们可以互访；
AR3
[AR3]ip vpn-instance ybd2
[AR3-vpn-instance-ybd2]route-distinguisher 10:1
[AR3-vpn-instance-ybd2-af-ipv4]vpn-target 10:1 both
[AR3-vpn-instance-ybd2-af-ipv4]int g0/0/1
[AR3-GigabitEthernet0/0/1]ip binding vpn-instance ybd2
[AR3-GigabitEthernet0/0/1]ip address 10.1.23.3 24
[AR3-GigabitEthernet0/0/1]bgp 10
[AR3-bgp]peer 10.1.23.2 as 1
[AR3-bgp]ipv4-family vpn-instance ybd2
[AR3-bgp-ybd2]peer 10.1.23.2 as 1
[AR3-bgp-ybd2]peer 10.1.23.2 substitute-as //做AS号的伪装
AR2
[AR2]bgp 1
[AR2-bgp]peer 10.1.23.3 as 10
[AR2-bgp]network 2.2.2.2 32
AR8
[AR8]ip vpn-instance ybd6
[AR8-vpn-instance-ybd10]route-distinguisher 10:1
[AR8-vpn-instance-ybd10-af-ipv4]vpn-target 10:1 both
[AR8-vpn-instance-ybd10-af-ipv4]int g0/0/2
[AR8-GigabitEthernet0/0/2]ip binding vpn-instance ybd10
[AR8-GigabitEthernet0/0/2]ip address 10.1.81.8 24
[AR8-GigabitEthernet0/0/2]bgp 20
[AR8-bgp]ipv4-family vpn-instance ybd6
[AR8-bgp-ybd10]peer 10.1.81.10 as 1
[AR8-bgp-ybd10]peer 10.1.81.10 substitute-as
AR10
[AR10]bgp 1
[AR10-bgp]peer 10.1.81.8 as 20
[AR10-bgp]network 10.10.10.10 32
[AR10]display ip routing-table protocol bgp
[AR2]ping -a 2.2.2.2 10.10.10.10
公司 B 2.2.2.2 访问公司 AD10.10.10.10
AR2 上的 IPv4 路由传递到 AR3
[AR2]dis ip routing-table 10.10.10.10
封装为：
查看10.10.10.10路由，下一跳是10.1.23.3；
然后根据AR3的接口下G0/0/0绑定的实例ybd2的路由表，去查相关路由。
[AR3]display ip routing-table vpn-instance ybd2 10.10.10.10
下一跳是 8.8.8.8
[AR3]display bgp vpnv4 vpn-instance ybd2 routing-table 10.10.10.10
私网标签1027 打上标签封装成：
接着是查看公网标签
[AR3]display mpls lsp
公网标签1026 打上标签封装成：
从G0/0/2接口出发
[AR4]dis mpls lsp
进来标签是1026，出标签为1027，从G0/0/1接口发出
打上标签封装成：
[AR5]dis mpls lsp
进来标签是1027，出标签为1026，
封装为：
[AR7]display mpls lsp
8.8.8.8出标签是3，然后进行弹出顶部标签，从G0/0/1接口发送出去。
[AR8]dis mpls lsp
[AR8]dis bgp vpnv4 vpn-instance ybd6 routing-table
下一跳是10.1.81.10
三、有 RR 的拓扑
四、配置与分析
4.1 概括
（1）AS内IGP和LDP配置好
（2）ASBR之间建立EBGP邻居，并启动传递标签ipv4路由能力，互联接口启动mpls（3）在ASBR向对端ASBR发布本端PE/RR的标签ipv4路由，通过产生标签策略完成
（4）在ASBR上开启LSP触发策略，为BGP路由产生LDP的LSP
（5）在ASBR上引入PE/RR的BGP路由到IGP协议中
（6）PE和RR之间建立mp-ibgp邻居关系，传递vp#v4路由，并保证路由传递到对端PE下一跳不变
（7）RR之间建立MP-EBGP邻居关系，传递vp#v4路由，并保证路由传递到对端下一跳不变
目的：是建立一条PE到PE之间的LSP，方便PE之间建立MP-EBGP传递vp#v4路由。
4.2 删除
删除掉 AR3和AR5的MP-IBGP邻居、AR6和AR8的MP-IBGP邻居、AR3和AR8的EBGP VP#v4 邻居关系；
4.3 然后建立AR4(RR)与AR3、AR7(RR)与AR8建立邻居关系并且下一跳不变，AR4与AR7建立EBGP VP#4的邻居关系。
AR3
[AR3]bgp 10
[AR3-bgp]peer 4.4.4.4 as 10
[AR3-bgp]peer 4.4.4.4 connect-interface LoopBack 0
[AR3-bgp]ipv4-family vpnv4
[AR3-bgp-af-vpnv4]peer 4.4.4.4 enable
[AR3-bgp-af-vpnv4]peer 4.4.4.4 next-hop-invariable
AR4
[AR4]bgp 10
[AR4-bgp]peer 3.3.3.3 as 10
[AR4-bgp]peer 3.3.3.3 connect-interface LoopBack 0
[AR4-bgp]ipv4-family vpnv4
[AR4-bgp-af-vpnv4]peer 3.3.3.3 enable
[AR4-bgp-af-vpnv4]peer 3.3.3.3 reflect-client
[AR4-bgp-af-vpnv4]peer 3.3.3.3 next-hop-invariable
[AR4-bgp-af-vpnv4]undo policy vpn-target
[AR4-bgp-af-vpnv4]q
[AR4-bgp]peer 7.7.7.7 as 20
[AR4-bgp]peer 7.7.7.7 connect-interface LoopBack 0
[AR4-bgp]peer 7.7.7.7 ebgp-max-hop 66
[AR4-bgp]ipv4-family vpnv4
[AR4-bgp-af-vpnv4]peer 7.7.7.7 enable
[AR4-bgp-af-vpnv4]peer 7.7.7.7 next-hop-invariable
AR7
[AR7]bgp 20
[AR7-bgp]peer 8.8.8.8 as 20
[AR7-bgp]peer 8.8.8.8 connect-interface LoopBack 0
[AR7-bgp]ipv4-family vpnv4
[AR7-bgp-af-vpnv4]peer 8.8.8.8 enable
[AR7-bgp-af-vpnv4]peer 8.8.8.8 reflect-client
[AR7-bgp-af-vpnv4]peer 8.8.8.8 next-hop-invariable
[AR7-bgp-af-vpnv4]undo policy vpn-target
[AR7-bgp-af-vpnv4]q
[AR7-bgp]peer 4.4.4.4 as 10
[AR7-bgp]peer 4.4.4.4 connect-interface LoopBack 0
[AR7-bgp]peer 4.4.4.4 ebgp-max-hop 66
[AR7-bgp]ipv4-family vpnv4
[AR7-bgp-af-vpnv4]peer 4.4.4.4 enable
[AR7-bgp-af-vpnv4]peer 4.4.4.4 next-hop-invariable
AR8
[AR8]bgp 20
[AR8-bgp]peer 7.7.7.7 as 20
[AR8-bgp]peer 7.7.7.7 connect-interface LoopBack 0
[AR8-bgp]ipv4-family vpnv4
[AR8-bgp-af-vpnv4]peer 7.7.7.7 enable
[AR8-bgp-af-vpnv4]peer 7.7.7.7 next-hop-invariable
4.4 宣告RR的网段LOOPBACK 0
AR5
[AR5]bgp 10
[AR5-bgp]network 4.4.4.4 32
AR6
[AR6]bgp 20
[AR6-bgp]network 7.7.7.7 32
4.5 测试
[AR4]dis bgp peer
[AR7]dis bgp peer
4.6 MPLS VP#业务接入，公司A访问公司C
AR3
[AR3]ip vpn-instance ybd66
[AR3-vpn-instance-ybd1]route-distinguisher 20:1
[AR3-vpn-instance-ybd1-af-ipv4]vpn-target 20:1 both
[AR3-vpn-instance-ybd1-af-ipv4]int g0/0/0
[AR3-GigabitEthernet0/0/0]ip binding vpn-instance ybd66
[AR3-GigabitEthernet0/0/0]ip address 10.1.13.3 24
[AR3-GigabitEthernet0/0/0]q
[AR3]ospf 1 router-id 3.3.3.3 vpn-instance ybd66
[AR3-ospf-1]a 0
[AR3-ospf-1-area-0.0.0.0]network 10.1.13.3 0.0.0.0
[AR3-ospf-1-area-0.0.0.0]q
[AR3-ospf-1]import-route bgp
[AR3-ospf-1]bgp 10
[AR3-bgp]ip
[AR3-bgp]ipv4-family vpn-instance ybd66
[AR3-bgp-ybd1]import-route ospf 1
AR1
[AR1]ospf 1
[AR1-ospf-1]a 0
[AR1-ospf-1-area-0.0.0.0]network 1.1.1.1 0.0.0.0
[AR1-ospf-1-area-0.0.0.0]network 10.1.13.1 0.0.0.0
AR8
[AR8]ip vpn-instance ybd99
[AR8-vpn-instance-ybd9]route-distinguisher 20:1
[AR8-vpn-instance-ybd9-af-ipv4]vpn-target 20:1 both
[AR8-vpn-instance-ybd9-af-ipv4]int g0/0/1
[AR8-GigabitEthernet0/0/1]ip binding vpn-instance ybd99
[AR8-GigabitEthernet0/0/1]ip address 10.1.89.8 24
[AR8-GigabitEthernet0/0/1]q
[AR8]isis 1 vpn-instance ybd99
[AR8-isis-1]import-route bgp
[AR8-isis-1]network-entity 12.0001.0000.0000.0008.00
[AR8-isis-1]is-level level-2
[AR8-isis-1]int g0/0/1
[AR8-GigabitEthernet0/0/1]isis enable 1
[AR8-GigabitEthernet0/0/1]bgp 20
[AR8-bgp]ipv4-family vpn-instance ybd99
[AR8-bgp-ybd9]import-route isis 1
AR9
[AR9]isis
[AR9-isis-1]network-entity 12.0001.0000.0000.0009.00
[AR9-isis-1]is-level level-2
[AR9-isis-1]int g0/0/0
[AR9-GigabitEthernet0/0/0]isis enable 1
[AR9]int l0
[AR9-LoopBack0]isis enable
[AR1]dis ip routing-table protocol ospf
[AR9]ping -a 9.9.9.9 1.1.1.1
1031是私网标签，1026是公网标签。
[AR3]display bgp vpnv4 vpn-instance ybd66 routing-table 9.9.9.9
OK
五、特点
跨域VP#-OptionC2的优缺点和跨域VP#-OptionC1一样，只是在配置方面稍微有些不一样。
特点：公网形成了一个架构，后面如果有公司接入进来的话，只需要在PE设备上配置接入MPLS VP#业务即可，公网不需要配置。
重要并且特别的配置，在ASBR上的MPLS视图下需要配置lsp-trigger bgp-label-route命令，把BGP协议引入到RIP（从逻辑的角度来看，多个AS域形成了一个AS域）；AR4(RR)与AR3建立MP-IBGP邻居关系，AR(RR)与AR7建立EBGP VP#V4邻居，把PE和RR的Looback 0网段宣告进BGP进程。
名言：
勤学如春起之苗，不见其增，日有所长；—陶渊明
好了这期就到这里了，如果你喜欢这篇文章的话，请点赞评论分享收藏，如果你还能点击关注，那真的是对我最大的鼓励。谢谢大家，下期见！