MPLS基本概念

  • MPLS(Multiprotocol Label Switching,多协议标签交换)
  • CE(Customer Edge,用户网络边缘)设备
  • PE(Provider Edge,服务提供商网络边缘)设备
  • LSR(Label Switching Router,标签交换路由器)
    • 具有标签分发能力和标签交换能力的设备。
  • AC(Attachment Circult)接入电路
    • 连接CE-PE的物理电路或虚拟电路。
  • PW(Pseudo-Wire,伪线)
    • 两个PE之间虚拟双向连接。
    • MPLS PW由一对方向相反的单向LSP构成。
    • 例如:peer 2.2.2.3 pw-id 100 in-label 100 out-label 200
    • 对应:peer 2.2.2.1 pw-id 100 in-label 200 out-label 100
  • 公网隧道(Tunnel)
    • 用来承载PW的隧道。可以承载多条PW。
  • 交叉连接(cross connect)
    • 两条物理电路或两条虚链路串连成一条连接。
    • 有三种:AC-AC AC-PW PW-PW
  • Site ID
    • 用户网络站点在×××内的唯一标识。
    • 不同×××内站点的site ID可以相同。
  • RD
    • 用来区分不同×××内site ID相同的站点。
    • 在site ID前增加RD,通过RD+site ID可以唯一标识网络中的一个站点。
  • 标签快(一组标签的集合)
    • LB(Label Base,初始标签)
    • LR(Label Range,标签范围)
    • LO(Label-block Offset,标签块偏移)
  • ××× target
    • MPLS L2***使用BGP扩展团体属性*** target(也称Route target)来控制BGP L2***信息的发布。
  • LDP(Label Distribution Protocol,标签分发协议)
    • 用来动态建立LSP。通过LDP,LSR可以把网络层的IP路由信息映射到MPLS的标签交换路径上。

注意

	此处的接口对应关系:
	e0 对应 gi1/0
	e1 对应 gi2/0
	e2 对应 gi3/0
	依次类推

本地mpls交换配置举例

[CE1]display current-configuration interface GigabitEthernet 1/0
#
interface GigabitEthernet1/0
 port link-mode route
 ip address 100.1.1.1 255.255.255.0
#
return

[CE2]display current-configuration interface GigabitEthernet 2/0
#
interface GigabitEthernet2/0
 port link-mode route
 ip address 100.1.1.2 255.255.255.0
#
return


[PE]display current-configuration 

 l2*** enable
xconnect-group ***1
 connection ***1
  ac interface GigabitEthernet1/0
  ac interface GigabitEthernet2/0

PE验证:
[PE]display l2*** forwarding ac 
Total number of cross-connections: 1
Total number of ACs: 2

AC                               Xconnect-group Name             Link ID
GE1/0                            ***1                            0      
GE2/0                            ***1                            1      
[PE]

CE1验证:
[CE1]ping 100.1.1.2
Ping 100.1.1.2 (100.1.1.2): 56 data bytes, press CTRL_C to break
56 bytes from 100.1.1.2: icmp_seq=0 ttl=255 time=26.309 ms
56 bytes from 100.1.1.2: icmp_seq=1 ttl=255 time=5.527 ms
56 bytes from 100.1.1.2: icmp_seq=2 ttl=255 time=3.591 ms
56 bytes from 100.1.1.2: icmp_seq=3 ttl=255 time=2.355 ms
56 bytes from 100.1.1.2: icmp_seq=4 ttl=255 time=4.193 ms

--- Ping statistics for 100.1.1.2 ---
5 packets transmitted, 5 packets received, 0.0% packet loss
round-trip min/avg/max/std-dev = 2.355/8.395/26.309/9.015 ms

静态PW配置举例

配置CE1

[CE1]vlan 100
[CE1-vlan100]quit
[CE1]interface vlan 100 
[CE1-Vlan-interface100]ip add 100.1.1.1 24
[CE1-Vlan-interface100]quit
[CE1]interface GigabitEthernet 1/0
[CE1-GigabitEthernet1/0]port link-mode bridge
[CE1-GigabitEthernet1/0]port link-type trunk 
[CE1-GigabitEthernet1/0]port trunk permit vlan all
[CE1-GigabitEthernet1/0]quit

配置PE1

# 配置LSR ID
[PE1]interface LoopBack 0 
[PE1-LoopBack0]ip add 2.2.2.1 32
[PE1-LoopBack0]quit
[PE1]mpls lsr-id 2.2.2.1

# 开启L2×××功能
[PE1]l2*** enable

# 全局使能LDP
[PE1]mpls ldp 
[PE1-ldp]quit

# 配置连接P路由器的接口,在接口上使能LDP
[PE1]interface GigabitEthernet 2/0
[PE1-GigabitEthernet2/0]ip add 1.1.1.1 24
[PE1-GigabitEthernet2/0]mpls enable 
[PE1-GigabitEthernet2/0]mpls ldp enable 
[PE1-GigabitEthernet2/0]quit

#在PE1上运行ospf,用于建立LSP
[PE1]ospf 1 router-id 2.2.2.1 
[PE1-ospf-1]area 0 
[PE1-ospf-1-area-0.0.0.0]network 2.2.2.1 0.0.0.0
[PE1-ospf-1-area-0.0.0.0]network 1.1.1.0 0.0.0.255
[PE1-ospf-1-area-0.0.0.0]quit
[PE1-ospf-1]quit

# 创建交叉连接组***100
[PE1]xconnect-group ***100 
# 在该交叉连接组内创建名称为svc的交叉连接
[PE1-xcg-***100]connection svc 
# 将连接CE1的接口与此交叉连接关联
[PE1-xcg-***100-svc]ac interface GigabitEthernet 1/0 
# 并在交叉连接内创建静态PW,以便将AC和PW关联。
[PE1-xcg-***100-svc]peer 2.2.2.3 pw-id 100 in-label 100 out-label 200 
[PE1-xcg-***100-svc-2.2.2.3-100]quit
[PE1-xcg-***100-svc]quit
[PE1-xcg-***100]quit

配置P

[P]interface LoopBack 0 
[P-LoopBack0]ip add 2.2.2.2 32
[P-LoopBack0]quit
[P]mpls lsr-id 2.2.2.2

[P]mpls ldp 
[P-ldp]quit

[P]interface GigabitEthernet 2/0
[P-GigabitEthernet2/0]ip add 1.1.1.2 24
[P-GigabitEthernet2/0]mpls ldp enable 
[P-GigabitEthernet2/0]quit

[P]interface GigabitEthernet 1/0
[P-GigabitEthernet1/0]ip add 3.3.3.1 24
[P-GigabitEthernet1/0]mpls enable
[P-GigabitEthernet1/0]mpls ldp enable
[P-GigabitEthernet1/0]quit

[P]ospf 1 router-id 2.2.2.2
[P-ospf-1]area 0 
[P-ospf-1-area-0.0.0.0]network 2.2.2.2 0.0.0.0
[P-ospf-1-area-0.0.0.0]network 1.1.1.0 0.0.0.255 
[P-ospf-1-area-0.0.0.0]network 3.3.3.0 0.0.0.255
[P-ospf-1-area-0.0.0.0]quit
[P-ospf-1]quit

配置PE2

[PE2]interface LoopBack 0 
[PE2-LoopBack0]ip add 2.2.2.3 32
[PE2-LoopBack0]quit
[PE2]mpls lsr-id 2.2.2.3

[PE2]l2*** enable
[PE2]mpls ldp
[PE2-ldp]quit

[PE2]interface GigabitEthernet 1/0
[PE2-GigabitEthernet1/0]ip add 3.3.3.2 24
[PE2-GigabitEthernet1/0]mpls enable
[PE2-GigabitEthernet1/0]mpls ldp enable
[PE2-GigabitEthernet1/0]quit

[PE2]ospf 1 router-id 2.2.2.3 
[PE2-ospf-1]area 0 
[PE2-ospf-1-area-0.0.0.0]network 2.2.2.3 0.0.0.0
[PE2-ospf-1-area-0.0.0.0]network 3.3.3.0 0.0.0.255
[PE2-ospf-1-area-0.0.0.0]quit
[PE2-ospf-1]quit

#创建交叉连接组***100,在该交叉连接组内创建名为svc的交叉连接,将连接CE2的接口与此交叉连接关联,并在交叉连接内创建静态PW,以便将AC和PW关联。
[PE2]xconnect-group ***100 
[PE2-xcg-***100]connection svc 
[PE2-xcg-***100-svc]ac interface gigabitethernet 2/0
[PE2-xcg-***100-svc]peer 2.2.2.1 pw-id 100 in-label 200 out-label 100
[PE2-xcg-***100-svc-2.2.2.1-100]quit
[PE2-xcg-***100-svc]quit
[PE2-xcg-***100]quit

配置CE2

[CE2]vlan 100 
[CE2-vlan100]quit
[CE2]interface vlan 100
[CE2-Vlan-interface100]ip add 100.1.1.2 24
[CE2-Vlan-interface100]quit

[CE2]interface GigabitEthernet 2/0
[CE2-GigabitEthernet2/0]port link-mode bridge
[CE2-GigabitEthernet2/0]port link-type trunk 
[CE2-GigabitEthernet2/0]port trunk permit vlan all
[CE2-GigabitEthernet2/0]quit

验证

P路由器验证ospf

[P]display ospf peer 

         OSPF Process 1 with Router ID 2.2.2.2
               Neighbor Brief Information

 Area: 0.0.0.0        
 Router ID       Address         Pri Dead-Time  State             Interface
 2.2.2.3         3.3.3.2         1   39         Full/BDR          GE1/0
 2.2.2.1         1.1.1.1         1   38         Full/DR           GE2/0

PE路由器查看PW信息

PW是静态的。

[PE1]display l2*** pw
Flags: M - main, B - backup, H - hub link, S - spoke link, N - no split horizon
Total number of PWs: 1
1 up, 0 blocked, 0 down, 0 defect, 0 idle, 0 duplicate

Xconnect-group Name: ***100
Peer            PW ID/Rmt Site    In/Out Label    Proto   Flag  Link ID  State  
2.2.2.3         100               100/200         Static  M     1        Up 

CE路由器验证icmp

[CE1]ping 100.1.1.2
Ping 100.1.1.2 (100.1.1.2): 56 data bytes, press CTRL_C to break
56 bytes from 100.1.1.2: icmp_seq=0 ttl=255 time=74.608 ms
56 bytes from 100.1.1.2: icmp_seq=1 ttl=255 time=7.494 ms
56 bytes from 100.1.1.2: icmp_seq=2 ttl=255 time=9.578 ms
56 bytes from 100.1.1.2: icmp_seq=3 ttl=255 time=7.447 ms
56 bytes from 100.1.1.2: icmp_seq=4 ttl=255 time=9.788 ms

--- Ping statistics for 100.1.1.2 ---
5 packets transmitted, 5 packets received, 0.0% packet loss
round-trip min/avg/max/std-dev = 7.447/21.783/74.608/26.431 ms
[CE1]dis arp 
  Type: S-Static   D-Dynamic   O-Openflow   R-Rule   M-Multiport  I-Invalid
IP address      MAC address    VLAN     Interface                Aging Type 
100.1.1.2       7425-8ae3-7c02 100      GE1/0                    20    D  

动态PW配置举例

动态和静态的区别就在于创建PW的时候,没有指定in-label和out-label 如下:

[PE1]display current-configuration | begin xconnect
xconnect-group ***100 
 connection ldp
  ac interface GigabitEthernet1/0
  peer 2.2.2.3 pw-id 100
----------------------------------------------------------------------	
[PE2]display current-configuration | begin xconnect
xconnect-group ***a100  #配置name是可以不一样的
 connection ***100  #配置name是可以不一样的
  ac interface GigabitEthernet2/0
  peer 2.2.2.1 pw-id 100

**验证:**PW是LDP。

[PE1]display l2*** pw
Flags: M - main, B - backup, H - hub link, S - spoke link, N - no split horizon
Total number of PWs: 1
1 up, 0 blocked, 0 down, 0 defect, 0 idle, 0 duplicate

Xconnect-group Name: ***100
Peer            PW ID/Rmt Site    In/Out Label    Proto   Flag  Link ID  State  
2.2.2.3         100               917631/917629   LDP     M     1        Up  


[PE2]display l2*** pw
Flags: M - main, B - backup, H - hub link, S - spoke link, N - no split horizon
Total number of PWs: 1
1 up, 0 blocked, 0 down, 0 defect, 0 idle, 0 duplicate

Xconnect-group Name: ***a100
Peer            PW ID/Rmt Site    In/Out Label    Proto   Flag  Link ID  State  
2.2.2.1         100               917629/917631   LDP     M     1        Up