以后我还将继续推出高级MPLS/××× 配置和CCIE SP 等其它专题。
感谢:CISCO Documentation Online
感谢:我的朋友Vivy!
雪山飞鹄2005 年1 月
MSN: Mr_Flying@hotmail.com
MPLS 准许多个Site 通过Service Provider 的网络透明互联。一个ISP 的网络可以支持多个不同的IP ×××,每个×××对客户来说,是个单独的私有网络,和其它的客户都是独立的。在一个×××里面,每个site 可以发送IP 包给同一个××× 里的其它Site。换句话来说,MPLS/×××对于客户来说,相当于一个透明的三层传输网络,以前可以通过租用Leased Line 互联,现在可以租用MPLS/××× 链路互联。
路由器通过MP-BGP的扩展community 标签来分发××× 路由信息
· Cisco IOS. Release 12.2(6h),支持MPLS ××× feature.
· P 路由器:Cisco 7200 系列路由器.
· PE 路由器:Cisco 2691, 或者3640 系列路由器.
· 任何可以和PE 交换路由信息的路由器都可以作为C 和CE 路由器.
缩写约定
· P - Provider's core router.
· PE - Provider's edge router.
· CE - Customer's edge router.
· C - Customer's router.
我们将用下面的拓扑图进行举例说明:
网络拓扑图
本文档使用下面的拓扑图,网络中有3 台P 路由器、2 台PE 路由器(Pescara 和Pesaro),2 个
××× 客户分别是Customer_A 和Customer_B:
启用ip cef
使用下面的过程启用ip cef.,为了提高性能,可以在支持的路由器上使用ip cef distributed命令。
当在接口上配置了MPLS 后(在接口上配置 tag-switching ip).,还要在PE 上完成下面的步骤:
o 为每个×××指定正确的RD.这是为了扩展IP 地址之用,以便你可以识别IP 地址属于哪个×××.
route-target [export|import|both]
3. 配置PE-CE 间使用的路由协议,可是使用静态路由或者动态路由(RIP、OSPF、BGP).
o 重分布静态、RIP、或者OSPF 路由
o 重分布直连的路由
o Activate 和CE 路由器间的BGP 邻居
o Activate the neighbors. Activate 邻居
o 指定必须使用扩展community,这是必须的.
本例中的5 台路由器配置如下:
Pescara |
Current configuration:
! version 12.2 ! hostname Pescara ! ip cef ! !--- Customer_A 的配置. ip vrf Customer_A !---启用Customer_A 的××× 路由和转发表 (VRF). rd 100:110 !--- Route distinguisher creates routing and forwarding
!--- tables for a VRF. route-target export 100:1000 !--- Creates lists of import and export route-target extended !--- communities for the specified VRF. route-target import 100:1000 ! !--- Customer_B 配置. ip vrf Customer_B rd 100:120 route-target export 100:2000 route-target import 100:2000 ! interface Loopback0 ip address 10.10.10.4 255.255.255.255 ip router isis !--- Customer_A 的配置. interface Loopback101 ip vrf forwarding Customer_A !---将一个接口或者自接口和一个VRF 实例关联起来. ip address 200.0.4.1 255.255.255.0 !--- Loopback101 和 102 使用相同的IP 地址 200.0.4.1.这是准许的,因为它们属于2 个不用 客户的VRF no ip directed-broadcast ! !--- Customer_B 的配置. interface Loopback102 ip vrf forwarding Customer_B ip address 200.0.4.1 255.255.255.0 !--- Loopback101 和 102 使用相同的IP 地址 200.0.4.1.这是准许的,因为它们属于2 个不用 客户的VRF no ip directed-broadcast ! interface Serial2/0 no ip address no ip directed-broadcast encapsulation frame-relay
no fair-queue ! interface Serial2/0.1 point-to-point description link to Pauillac bandwidth 512 ip address 10.1.1.14 255.255.255.252 no ip directed-broadcast ip router isis tag-switching ip frame-relay interface-dlci 401 ! router isis net 49.0001.0000.0000.0004.00 is-type level-1 ! router bgp 100 bgp log-neighbor-changes !--- 启用BGP 邻居关系中断的记录. neighbor 10.10.10.6 remote-as 100 neighbor 10.10.10.6 update-source Loopback0 !--- 配置BGP 邻居. ! !--- Customer A and B commands. address-family vpnv4 !--- 进入address-family vpnv4 配置模式,配置和PE/P 路由器间的MP-BGP 路由会话。 neighbor 10.10.10.6 activate neighbor 10.10.10.6 send-community both !--- Sends the community attribute to a BGP neighbor. exit-address-family ! !--- Customer B commands. address-family ipv4 vrf Customer_B !--- 进入address-family ipv4 的配置模式下,配置和CE 间的路由会话, redistribute connected no auto-summary no synchronization exit-address-family ! !--- Customer A commands. address-family ipv4 vrf Customer_A redistribute connected no auto-summary no synchronization exit-address-family ! ip classless ! end |
Pesaro |
Current configuration:
! version 12.1 ! hostname Pesaro ! !--- Customer A commands. ip vrf Customer_A rd 100:110 route-target export 100:1000 route-target import 100:1000 ! !--- Customer B commands. ip vrf Customer_B rd 100:120 route-target export 100:2000 route-target import 100:2000 ! ip cef ! interface Loopback0 ip address 10.10.10.6 255.255.255.255 ip router isis !--- Customer A commands. interface Loopback101 ip vrf forwarding Customer_A ip address 200.0.6.1 255.255.255.0 ! !--- Customer B commands.
interface Loopback102 ip vrf forwarding Customer_B ip address 200.0.6.1 255.255.255.0 ! !--- Customer A commands. interface Loopback111 ip vrf forwarding Customer_A ip address 200.1.6.1 255.255.255.0 ! interface Serial0/0 no ip address encapsulation frame-relay no ip mroute-cache random-detect ! interface Serial0/0.1 point-to-point description link to Pomerol bandwidth 512 ip address 10.1.1.22 255.255.255.252 ip router isis tag-switching ip frame-relay interface-dlci 603 ! router isis net 49.0001.0000.0000.0006.00 is-type level-1 ! router bgp 100 neighbor 10.10.10.4 remote-as 100 neighbor 10.10.10.4 update-source Loopback0 ! !--- Customer B commands. address-family ipv4 vrf Customer_B redistribute connected no auto-summary no synchronization exit-address-family ! !--- Customer A commands. address-family ipv4 vrf Customer_A redistribute connected no auto-summary no synchronization exit-address-family ! !--- Customer A and B commands. address-family vpnv4 neighbor 10.10.10.4 activate neighbor 10.10.10.4 send-community both exit-address-family ! ip classless ! end |
Pomerol |
Current configuration:
! version 12.0 ! hostname Pomerol ! ip cef ! interface Loopback0 ip address 10.10.10.3 255.255.255.255 ip router isis ! interface Serial0/1 no ip address no ip directed-broadcast encapsulation frame-relay random-detect ! interface Serial0/1.1 point-to-point description link to Pauillac ip address 10.1.1.6 255.255.255.252 no ip directed-broadcast ip router isis tag-switching mtu 1520 tag-switching ip frame-relay interface-dlci 301 ! interface Serial0/1.2 point-to-point description link to Pulligny ip address 10.1.1.9 255.255.255.252 no ip directed-broadcast ip router isis tag-switching ip frame-relay interface-dlci 303 ! interface Serial0/1.3 point-to-point description link to Pesaro ip address 10.1.1.21 255.255.255.252 no ip directed-broadcast ip router isis tag-switching ip frame-relay interface-dlci 306 ! router isis net 49.0001.0000.0000.0003.00 is-type level-1 ! ip classless ! end |
Pulligny |
Current configuration:
! version 12.1 ! hostname Pulligny ! ! ip cef ! ! interface Loopback0 ip address 10.10.10.2 255.255.255.255 ! interface Serial0/1 no ip address encapsulation frame-relay random-detect ! interface Serial0/1.1 point-to-point description link to Pauillac ip address 10.1.1.2 255.255.255.252 ip router isis tag-switching ip frame-relay interface-dlci 201 ! interface Serial0/1.2 point-to-point description link to Pomerol ip address 10.1.1.10 255.255.255.252 ip router isis tag-switching ip frame-relay interface-dlci 203 ! router isis passive-interface Loopback0 net 49.0001.0000.0000.0002.00 is-type level-1 ! ip classless ! end |
Pauillac |
version 12.1
! hostname pauillac ! ip cef ! interface Loopback0 ip address 10.10.10.1 255.255.255.255 ip router isis ! interface Serial0/0 no ip address encapsulation frame-relay no ip mroute-cache tag-switching ip no fair-queue ! interface Serial0/0.1 point-to-point description link to Pomerol bandwith 512 ip address 10.1.1.1 255.255.255.252 ip router isis tag-switching ip frame-relay interface-dlci 102 ! interface Serial0/0.2 point-to-point description link to Pulligny ip address 10.1.1.5 255.255.255.252 ip router isis tag-switching ip frame-relay interface-dlci 103 ! interface Serial0/0.3 point-to-point description link to Pescara bandwidth 512 ip address 10.1.1.13 255.255.255.252 ip router isis tag-switching ip frame-relay interface-dlci 104 ! router isis net 49.0001.0000.0000.0001.00 is-type level-1 ! ip classless ! end |
本节讲述了如何检查你的配置是否工作正常.
· show ip vrf - Verifies that the correct VRF exists.
· show ip vrf interfaces - Verifies the activated interfaces.
· show ip route vrf Customer_A - Verifies the routing information on the PE routers.
· traceroute vrf Customer_A 200.0.6.1 - Verifies the routing information on the PE routers.
· show ip bgp vpnv4 tag - Verifies the BGP.
· show ip cef vrf Customer_A 200.0.6.1 detail - Verifies the routing information on the PE routers.
下面的输出是命令 show ip vrf 的结果
Pescara#show ip vrf
Name Default RD Interfaces
Customer_A 100:110 Loopback101
Customer_B 100:120 Loopback102
Pesaro#show ip vrf interfaces
Interface IP-Address VRF Protocol
Loopback101 200.0.6.1 Customer_A up
Loopback111 200.1.6.1 Customer_A up
Loopback102 200.0.6.1 Customer_B up
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
C 200.0.4.0/24 is directly connected, Loopback101
B 200.0.6.0/24 [200/0] via 10.10.10.6, 05:10:11
B 200.1.6.0/24 [200/0] via 10.10.10.6, 04:48:11
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
C 200.0.4.0/24 is directly connected, Loopback102
B 200.0.6.0/24 [200/0] via 10.10.10.6, 00:03:24
(如果配置mpls ip ttl .)
Pescara#traceroute vrf Customer_A 200.0.6.1
Type escape sequence to abort. Tracing the route to 200.0.6.1
1 10.1.1.13 [MPLS: Labels 20/26 Exp 0] 400 msec 276 msec 264 msec
2 10.1.1.6 [MPLS: Labels 18/26 Exp 0] 224 msec 460 msec 344 msec
3 200.0.6.1 108 msec * 100 msec