在 Cat9500 和 ISR4K 之间配置 VPLS

简介

VPLS 是第 2 层扩展技术，大多数客户通过 ISP 和第三方供应商的借用/租用服务使用该技术。VPLS的使用超出了本配置指南的范围。本基本配置指南旨在帮助客户在现有ISR4K平台和新的Cat9500交换机之间配置L2VPN。 

先决条件

您应该了解基本的L2VPN概念和配置伪线模板以配置L2 VFI情景

要求

ISR4K路由器（任何ISR4400/ISR4300）、Cat9500交换机和两个设备用作CE设备

使用的组件

ISR4451-X

C9500-40X-A

CISCO1921

CISCO2911

配置

配置说明VPLS情景的用法和支持的VC类型/详细信息

网络图

配置

在CE1和CE2上：

CE1#sh run
Building configuration...
 
Current configuration : 105 bytes
!
interface GigabitEthernet0/0
no ip address
duplex auto
speed auto
!
interface GigabitEthernet0/0.100
encapsulation dot1Q 100
ip address 101.101.101.2 255.255.255.0
!

CE2#sh run
Building configuration...
 
Current configuration : 1718 bytes
!
interface GigabitEthernet0/1
no ip address
duplex auto
speed auto
!
interface GigabitEthernet0/1.100
encapsulation dot1Q 100
ip address 101.101.101.1 255.255.255.0
!

在PE1和PE2上：

PE1#sh run
Building configuration... 
Current configuration : 5049 bytes
!
pseudowire-class VPLS100
encapsulation mpls
no control-word
!
l2 vfi 100 manual
vpn id 100
bridge-domain 100
mtu 9180
neighbor 3.3.3.3 pw-class VPLS100
!
interface Loopback0
ip address 2.2.2.2 255.255.255.255
!
interface GigabitEthernet0/0/0
mtu 9180
no ip address
negotiation auto
service instance 100 ethernet
  encapsulation dot1q 100
  rewrite ingress tag pop 1 symmetric
  bridge-domain 100
!
!
interface GigabitEthernet0/0/2
ip address 30.30.30.1 255.255.255.0
negotiation auto
mpls ip
!
ip route 3.3.3.3 255.255.255.255 30.30.30.2
!
mpls ldp router-id Loopback0 force
!

PE2#sh run
Building configuration... 

Current configuration : 10722 bytes
!
ip routing
!
pseudowire-class VPLS100
encapsulation mpls
no control-word
!
l2 vfi 100 manual
vpn id 100
neighbor 2.2.2.2 pw-class VPLS100
!
interface Loopback0
ip address 3.3.3.3 255.255.255.255
!
interface TenGigabitEthernet2/0/1
no switchport
ip address 30.30.30.2 255.255.255.0
mpls ip
!
interface TenGigabitEthernet2/0/2
switchport trunk allowed vlan 100
switchport mode trunk
!
interface Vlan100
no ip address
xconnect vfi 100
!
ip route 2.2.2.2 255.255.255.255 30.30.30.1
!
mpls ldp router-id Loopback0 force
!

注意：在运行在EFP（以太网流点）服务实例上的ISR4K和ASR1000设备上，确保我们在要扩展子网/广播域的各个SI（服务实例）下配置“rewrite ingress tag pop 1 symmetric”命令，以便ISR4K/ASR1k能够接收从CE端发送的已标记(802.1Q Vlan Tag)数据包。

验证

到目前为止，Cat9500平台在VPLS下支持与“以太网”的互联。因此首先检查VC类型为ethernet（默认）：

PE1#show mpls l2transport binding
  Destination Address: 3.3.3.3,VC ID: 100
    Local Label:  19
        Cbit: 0,    VC Type: Ethernet,    GroupID: n/a
        MTU: 9180,   Interface Desc: n/a
        VCCV: CC Type: RA [2], TTL [3]
              CV Type: LSPV [2]
    Remote Label: 17
        Cbit: 0,    VC Type: Ethernet,    GroupID: 0
        MTU: 9180,   Interface Desc: n/a
        VCCV: CC Type: RA [2], TTL [3]
              CV Type: LSPV [2]

PE2#show mpls l2transport binding
  Destination Address: 2.2.2.2,VC ID: 100
    Local Label:  17
        Cbit: 0,    VC Type: Ethernet,    GroupID: n/a
        MTU: 9180,   Interface Desc: n/a
        VCCV: CC Type: RA [2], TTL [3]
              CV Type: LSPV [2]
    Remote Label: 19
        Cbit: 0,    VC Type: Ethernet,    GroupID: 0
        MTU: 9180,   Interface Desc: n/a
        VCCV: CC Type: RA [2], TTL [3]
              CV Type: LSPV [2]

现在，其余命令与验证L2VPN VC的方式类似。但是，了解Cat9500具有系统mtu非常重要，因此您无法修改面向LAN端的单个接口MTU值。因此，您需要在ISR4K平台上的l2 vfi情景下显式配置“mtu <>”，以便根据Cat9500交换机上配置的系统mtu协商MTU值：

PE2:

PE2#show system mtu
Global Ethernet MTU is 9180 bytes.

PE1:

PE1#show mpls l2transport vc detail
Local interface: VFI 100 vfi up
  Interworking type is Ethernet
  Destination address: 3.3.3.3, VC ID: 100, VC status: up
    Output interface: Gi0/0/2, imposed label stack {17}
    Preferred path: not configured
    Default path: active
    Next hop: 30.30.30.2
  Create time: 00:02:10, last status change time: 00:02:10
    Last label FSM state change time: 00:02:10
  Signaling protocol: LDP, peer 3.3.3.3:0 up
    Targeted Hello: 2.2.2.2(LDP Id) -> 3.3.3.3, LDP is UP
    Graceful restart: not configured and not enabled
    Non stop routing: not configured and not enabled
    Status TLV support (local/remote)   : enabled/supported
      LDP route watch                   : enabled
      Label/status state machine        : established, LruRru
      Last local dataplane   status rcvd: No fault
      Last BFD dataplane     status rcvd: Not sent
      Last BFD peer monitor  status rcvd: No fault
      Last local AC  circuit status rcvd: No fault
      Last local AC  circuit status sent: No fault
      Last local PW i/f circ status rcvd: No fault
      Last local LDP TLV     status sent: No fault
      Last remote LDP TLV    status rcvd: No fault
      Last remote LDP ADJ    status rcvd: No fault
    MPLS VC labels: local 19, remote 17
    Group ID: local n/a, remote 0
    MTU: local 9180, remote 9180
    Remote interface description:
  Sequencing: receive disabled, send disabled
  Control Word: Off
  SSO Descriptor: 3.3.3.3/100, local label: 19
  Dataplane:
    SSM segment/switch IDs: 8387/4289 (used), PWID: 4
  VC statistics:
    transit packet totals: receive 0, send 0
    transit byte totals:   receive 0, send 0
    transit packet drops:  receive 0, seq error 0, send 0

PE2:

PE2#show mpls l2transport vc detail
Local interface: VFI 100 vfi up
  Interworking type is Ethernet
  Destination address: 2.2.2.2, VC ID: 100, VC status: up
    Output interface: Te2/0/1, imposed label stack {19}
    Preferred path: not configured
    Default path: active
    Next hop: 30.30.30.1
  Create time: 01:02:03, last status change time: 00:03:09
    Last label FSM state change time: 00:03:09
  Signaling protocol: LDP, peer 2.2.2.2:0 up
    Targeted Hello: 3.3.3.3(LDP Id) -> 2.2.2.2, LDP is UP
    Graceful restart: not configured and not enabled
    Non stop routing: not configured and not enabled
    Status TLV support (local/remote)   : enabled/supported
      LDP route watch                   : enabled
      Label/status state machine        : established, LruRru
      Last local dataplane   status rcvd: No fault
      Last BFD dataplane     status rcvd: Not sent
      Last BFD peer monitor  status rcvd: No fault
      Last local AC  circuit status rcvd: No fault
      Last local AC  circuit status sent: No fault
      Last local PW i/f circ status rcvd: No fault
      Last local LDP TLV     status sent: No fault
      Last remote LDP TLV    status rcvd: No fault
      Last remote LDP ADJ    status rcvd: No fault
    MPLS VC labels: local 17, remote 19
    Group ID: local n/a, remote 0
    MTU: local 9180, remote 9180
    Remote interface description:
  Sequencing: receive disabled, send disabled
  Control Word: Off
  SSO Descriptor: 2.2.2.2/100, local label: 17
  Dataplane:
    SSM segment/switch IDs: 12297/8194 (used), PWID: 1
  VC statistics:
    transit packet totals: receive 0, send 0
    transit byte totals:   receive 0, send 0
    transit packet drops:  receive 0, seq error 0, send 0

现在，当我们尝试从CE1 ping CE2时：

CE1#ping 101.101.101.1 source 101.101.101.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 101.101.101.1, timeout is 2 seconds:
Packet sent with a source address of 101.101.101.2
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms

然后我们检查VC统计信息以确保数据包通过VPLS传输：

PE1:

PE1#show mpls l2transport vc detail | sec statistics
  VC statistics:
    transit packet totals: receive 5, send 5
    transit byte totals:   receive 660, send 660
    transit packet drops:  receive 0, seq error 0, send 0

PE2:

PE2#show mpls l2transport vc detail | sec statistics
  VC statistics:
    transit packet totals: receive 5, send 5
    transit byte totals:   receive 680, send 680
    transit packet drops:  receive 0, seq error 0, send 0

故障排除

本文档旨在强调在ISR/ASR路由器与充当PE节点的Cat9500交换机之间配置VPLS VC时的兼容性问题，因此目前没有故障排除步骤。