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
一、拓扑
二、配置
三、跨域VP#-OptionC1方案的特点
由于特殊原因，所以把“N”字母替换为“#”符号
（1）AS内LSP lable分发跟LDP相关
（2）ASBR之间发布PE路由器的BGP lable
（3）PE之间发布vp#v4路由的私网标签
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.MPLS
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
3.MP-IBGP、MP-EBGP、标签、VP#V4
AR3
[AR3]bgp 10
[AR3-bgp]peer 4.4.4.4 as-number 10
[AR3-bgp]peer 4.4.4.4 connect-interface LoopBack0
[AR3-bgp]peer 4.4.4.4 label-route-capability
[AR3-bgp]ipv4-family vpnv4
[AR3-bgp-af-vpnv4]peer 4.4.4.4 enable
AR4（ RR）
[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]peer 5.5.5.5 as 10
[AR4-bgp]peer 5.5.5.5 connect-interface LoopBack 0
[AR4-bgp]peer 7.7.7.7 as-number 20
[AR4-bgp]peer 7.7.7.7 ebgp-max-hop 66
[AR4-bgp]peer 7.7.7.7 connect-interface LoopBack0
[AR4-bgp]peer 3.3.3.3 reflect-client
[AR4-bgp]peer 3.3.3.3 label-route-capability
[AR4-bgp]peer 5.5.5.5 reflect-client
[AR4-bgp]peer 5.5.5.5 label-route-capability
[AR4-bgp]ipv4-family vpnv4
[AR4-bgp-af-vpnv4]undo policy vpn-target
[AR4-bgp-af-vpnv4]peer 3.3.3.3 reflect-client
[AR4-bgp-af-vpnv4]peer 3.3.3.3 enable
[AR4-bgp-af-vpnv4]peer 7.7.7.7 enable
[AR4-bgp-af-vpnv4]peer 7.7.7.7 next-hop-invariable
AR5
[AR5]route-policy asbr permit node 10
[AR5-route-policy]apply mpls-label
[AR5-route-policy]q
[AR5]route-policy pe permit node 10
[AR5-route-policy]if-match mpls-label
[AR5-route-policy]apply mpls-label
[AR5-route-policy]q
[AR5]bgp 10
[AR5-bgp]peer 4.4.4.4 as 10
[AR5-bgp]peer 4.4.4.4 connect-interface LoopBack 0
[AR5-bgp]peer 10.1.56.6 as-number 20
[AR5-bgp]peer 4.4.4.4 route-policy pe export
[AR5-bgp]peer 4.4.4.4 label-route-capability
[AR5-bgp]peer 10.1.56.6 route-policy asbr export
[AR5-bgp]peer 10.1.56.6 label-route-capability
[AR5-bgp]network 3.3.3.3 255.255.255.255
[AR5-bgp]network 4.4.4.4 255.255.255.255
[AR5-bgp]q
[AR4-rip-1]dis bgp peer
AR6、AR7、AR8、AR9、AR10的MP-IBGP、MPLS配置类似
5.MPLS VP#业务接入
配置好公网，然后是公司BB访问公司DD；
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
[AR3-bgp]dis bgp vp#v4 all peer
[AR3]dis bgp vp#v4 all routing-table
AR8
[AR8]ip vpn-instance ybd10
[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 ybd10
[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
[AR2]dis ip routing-table
6.MPLS VP#业务接入
公司AA访问公司CC；
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
[AR9]dis ip routing-table
公司 CC 9.9.9.9 访问公司 AA1.1.1.1
[AR1]ping -a 1.1.1.1 9.9.9.9
AR3的G0/0/2接口上进行抓包
标签为三层标签。1025为LDP标签，1027为公网标签，1028为私网标签。
公司 AA 到公司 CC 的路由传递
（1）AR1 上的 IPv4 路由传递到 AR3
[AR1]dis ip routing-table 9.9.9.9
封装为：
查看9.9.9.9路由，下一跳是10.1.13.3；
然后根据AR3的接口下G0/0/0绑定的实例ybd66的路由表，去查相关路由。
（2）AR3 将其引入 VP#v4 路由表后，携带私网标签、RT、下一跳等单播传递给 AR8。
下一跳是 8.8.8.8
[AR3]dis bgp vp#v4 vp#-instance ybd66 routing-table 9.9.9.9
私网标签1028 打上标签封装成：
然后查看公网标签
[AR3]dis mpls lsp
打上标签封装成：
[AR3]dis ip routing-table 8.8.8.8
[AR3]dis mpls lsp
从G0/0/2接口发出。
打上标签封装成：
5.5.5.5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。
封装成：
[AR5]dis mpls lsp
封装成：
[AR6]dis mpls lsp
从G0/0/1接口发送出去。
封装成：
[AR7]dis 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。
封装成：
（3）AR8 匹配 RT 值后，剥离 RD 和私网标签引入实例 ybd99
[AR8]dis mpls lsp
封装成：
[AR8]dis ip routing-table vp#-instance ybd99
下一跳是10.1.89.9
标签
R5分配的标签
3.3.3.3/32 1029/NULL -/-
4.4.4.4/32 1026/NULL -/-
R6收到的标签
4.4.4.4/32 NULL/1026 -/-
3.3.3.3/32 NULL/1029 -/-
收到再为其分配的标签
4.4.4.4/32 1027/1026 -/-
3.3.3.3/32 1028/1029 -/-
这两个标签是为其分配的空口标签，即IPv4路由在R6上可以进行标签传输
4.4.4.4/32 NULL/1026 -/-
3.3.3.3/32 NULL/1029 -/-
R7上作为RR，不修改标签，也不分配标签
4.4.4.4/32 NULL/1027 -/-
3.3.3.3/32 NULL/1028 -/-
R8收到的反射的标签路由
4.4.4.4/32 NULL/1027 -/-
3.3.3.3/32 NULL/1028 -/-
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VPN业务，公网不需要配置。
优点： VP# 路由在入口 PE 和出口 PE 之间直接交换，不需要中间设备的保存和转发。VP# 的路由信息出现在 PE 和 RR设备上，而 ASBR 只负责报文的转发，使得中间域的设备可以不支持 MPLS VP# 业务，只需支持 MPLS 转发，ASBR 设备不再成为性能瓶颈。因此跨域 VP#-OptionC更适合在跨越多个 AS 时使用。更适合支持 MPLS VP# 的负载分担。
缺点： 维护一条端到端的 PE 连接管理代价较大。
名言：
不要把最美好的时光都浪费在睡觉上。
欢迎访问我的易百纳技术社区文章《华为 跨域VP#-OptionC1方案》
https://www.ebaina.com/articles/140000005445
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！
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