目  录

1 简介

2 配置前提

3 配置举例

3.1 组网需求

3.2 配置思路

3.3 适用产品及版本

3.4 配置注意事项

3.5 配置步骤

3.5.1 开启CFD功能

3.5.2 配置VLAN与接口

3.5.3 配置服务实例

3.5.4 配置MEP

3.5.5 配置MIP的创建规则

3.5.6 启用MEP的连续性检测功能

3.6 验证配置

3.7 配置文件

 

1  简介

本文档介绍通过在网络中使用CFD功能，可以实现在二层网络中检测链路连通性，确认故障并确定故障发生的位置。

2  配置前提

本文档中的配置均是在实验室环境下进行的配置和验证，配置前设备的所有参数均采用出厂时的缺省配置。如果您已经对设备进行了配置，为了保证配置效果，请确认现有配置和以下举例中的配置不冲突。

本文档假设您已了解CFD特性。

3  配置举例

3.1  组网需求

某公司网络如图1所示，设备Device B、Device C位于中央机房，设备Device A、Device D、Device E分布在其它区域。VLAN 20内的用户（研发部）分别通过Device A和Device D接入公司网络，VLAN 30内的用户（市场部）分别通过Device A和Device E接入公司网络。

现要求在该网络中配置CFD功能，实现当某条链路发生故障，CFD功能能够确认故障并对故障进行定位。

图1 组网示意图

 

3.2  配置思路

·     为了较好的规划CFD功能所作用的区域，可以根据设备所在的位置来划分MD（便于故障定位）。根据各MD的范围来确定MD的级别，确保低级别MD嵌套于高级别MD中。本案例将公司整个网络划分为MD_A（level 5），将中央机房的网络划分为MD_B（level 3）。

·     为了较好的规划CFD功能所作用的区域，可以根据业务流量所属的VLAN来划分MA。本案例中将MD_A的VLAN 20划分为MA_A_1，MD_A的VLAN 30划分为MA_A_2；将MD_B的VLAN 20划分为MA_B_1，MD_B的VLAN 30划分为MA_B_2。

·     为了实现CFD能够检测网络的链路连通性的功能，需要在位于MA边界的接口上配置MEP，并根据该接口对CFD协议报文的发送情况确定MEP的类型。

¡     例如，MA_B_1所对应的VLAN为VLAN 20，位于MA_B_1允许VLAN 20通过的接口有Device B的接口XGE1/0/1和XGE1/0/2、Device C的接口XGE1/0/1和XGE1/0/2、Device D的接口XGE1/0/1。可以看出MA_B_1的边界的接口分别为Device B的接口XGE1/0/1和Device D的接口XGE1/0/1，因此我们需要在这两个接口上配置MEP；

¡     由于Device B的接口XGE1/0/1发送的CFD协议报文需要从本设备其他接口转发出去，因此该接口需配置为内向MEP；而Device D的XGE1/0/1发送的CFD协议报文直接从该接口发送出去，该接口需配置为外向MEP。

·     由于Device C为MD_B的中间设备，为了准确定位Device B和Device D之间链路故障，需要在Device C上配置MIP，并选择合适的MIP生成规则。本例中，将Device C作为MIP，创建规则为default规则。

·     为了检测各MA内的MEP之间的连通状态，需要开启连续性检测功能。

·     当CFD的连续性检测功能检测到链路故障时，可以使用环回功能进行故障确认，并在获取到整个组网的状态后，使用链路跟踪功能进行路径查找或故障定位。

综合以上配置思路，配置CFD功能示意图如图2所示。

图2 CFD功能示意图

 

3.3  适用产品及版本

表1 适用产品及版本

产品	软件版本
S6550X-HI系列	Release 1213P01及以上版本
S6880系列	Release 1213P01及以上版本
S9820-8M	Release 1213P01及以上版本
S5580X-HI系列	Release 1213P01及以上版本
S5580X-EI系列	Release 1213P01及以上版本
S5580S-EI系列	Release 1213P01及以上版本

 

3.4  配置注意事项

·     在创建MEP时，该MEP的ID必须已包含在对应服务实例的MEP列表中，否则不能创建成功。

·     一个MD内可以有多个MA，但一个MA只能与一个检测VLAN进行关联。

·     同一MA中所有MEP发送的CCM报文中时间间隔域的值必须相同。本案例中不对MEP发送的CCM报文中时间间隔域进行修改，即均采用缺省配置。

3.5  配置步骤

3.5.1  开启CFD功能

# 在Device A上开启CFD功能。

<DeviceA> system-view

[DeviceA] cfd enable

Device B～Device E的配置与Device A相同，配置过程略。

3.5.2  配置VLAN与接口

1. Device A的配置

[DeviceA] vlan 20

[DeviceA-vlan20] quit

[DeviceA] vlan 30

[DeviceA-vlan30] quit

[DeviceA] interface twenty-fivegige 1/0/1

[DeviceA-Twenty-FiveGigE1/0/1] port access vlan 20

[DeviceA-Twenty-FiveGigE1/0/1] quit

[DeviceA] interface twenty-fivegige 1/0/2

[DeviceA-Twenty-FiveGigE1/0/2] port access vlan 30

[DeviceA-Twenty-FiveGigE1/0/2] quit

[DeviceA] interface twenty-fivegige 1/0/3

[DeviceA-Twenty-FiveGigE1/0/3] port link-type trunk

[DeviceA-Twenty-FiveGigE1/0/3] port trunk permit vlan 20 30

[DeviceA-Twenty-FiveGigE1/0/3] quit

2. Device B的配置

[DeviceB] vlan 20

[DeviceB-vlan20] quit

[DeviceB] vlan 30

[DeviceB-vlan30] quit

[DeviceB] interface twenty-fivegige 1/0/1

[DeviceB-Twenty-FiveGigE1/0/1] port link-type trunk

[DeviceB-Twenty-FiveGigE1/0/1] port trunk permit vlan 20 30

[DeviceB-Twenty-FiveGigE1/0/1] quit

[DeviceB] interface twenty-fivegige 1/0/2

[DeviceB-Twenty-FiveGigE1/0/2] port link-type trunk

[DeviceB-Twenty-FiveGigE1/0/2] port trunk permit vlan 20

[DeviceB-Twenty-FiveGigE1/0/2] quit

[DeviceB] interface twenty-fivegige 1/0/3

[DeviceB-Twenty-FiveGigE1/0/3] port link-type trunk

[DeviceB-Twenty-FiveGigE1/0/3] port trunk permit vlan 30

[DeviceB-Twenty-FiveGigE1/0/3] quit

3. Device C的配置

[DeviceC] vlan 20

[DeviceC-vlan20] quit

[DeviceC] interface twenty-fivegige 1/0/1

[DeviceC-Twenty-FiveGigE1/0/1] port link-type trunk

[DeviceC-Twenty-FiveGigE1/0/1] port trunk permit vlan 20

[DeviceC-Twenty-FiveGigE1/0/1] quit

[DeviceC] interface twenty-fivegige 1/0/2

[DeviceC-Twenty-FiveGigE1/0/2] port link-type trunk

[DeviceC-Twenty-FiveGigE1/0/2] port trunk permit vlan 20

[DeviceC-Twenty-FiveGigE1/0/2] quit

4. Device D的配置

[DeviceD] vlan 20

[DeviceD-vlan20] quit

[DeviceD] interface twenty-fivegige 1/0/1

[DeviceD-Twenty-FiveGigE1/0/1] port link-type trunk

[DeviceD-Twenty-FiveGigE1/0/1] port trunk permit vlan 20

[DeviceD-Twenty-FiveGigE1/0/1] quit

[DeviceD] interface twenty-fivegige 1/0/2

[DeviceD-Twenty-FiveGigE1/0/2] port access vlan 20

[DeviceD-Twenty-FiveGigE1/0/2] quit

5. Device E的配置

[DeviceE] vlan 30

[DeviceE-vlan30] quit

[DeviceE] interface twenty-fivegige 1/0/1

[DeviceE-Twenty-FiveGigE1/0/1] port access vlan 30

[DeviceE-Twenty-FiveGigE1/0/1] quit

[DeviceE] interface twenty-fivegige 1/0/2

[DeviceE-Twenty-FiveGigE1/0/2] port link-type trunk

[DeviceE-Twenty-FiveGigE1/0/2] port trunk permit vlan 30

[DeviceE-Twenty-FiveGigE1/0/2] quit

3.5.3  配置服务实例

根据CFD功能示意图中每台设备上的接点所属的MD中的MA，共需要完成表2配置。

表2 关系对应表

设备	MD	MD级别	MA	VLAN	服务实例
Device A	MD_A	5	MA_A_1	20	1
			MA_A_2	30	2
Device B	MD_B	3	MA_B_1	20	3
			MA_B_2	30	4
Device C	MD_B	3	MA_B_1	20	3
Device D	MD_A	5	MA_A_1	20	1
	MD_B	3	MA_B_1	20	3
Device E	MD_A	5	MA_A_2	30	2
	MD_B	3	MA_B_2	30	4

 

1. Device A的配置

# 在Device A上创建级别为5的MD，MD名称为MD_A。

[DeviceA] cfd md MD_A level 5

# 创建服务实例1，该服务实例的MA名称为MA_A_1，且服务于VLAN 20。

[DeviceA] cfd service-instance 1 ma-id string MA_A_1 md MD_A vlan 20

# 创建服务实例2，该服务实例的MA名称为MA_A_2，且服务于VLAN 30。

[DeviceA] cfd service-instance 2 ma-id string MA_A_2 md MD_A vlan 30

Device B～Device E的配置与Device A相似。

2. Device B的配置

[DeviceB] cfd md MD_B level 3

[DeviceB] cfd service-instance 3 ma-id string MA_B_1 md MD_B vlan 20

[DeviceB] cfd service-instance 4 ma-id string MA_B_2 md MD_B vlan 30

3. Device C的配置

[DeviceC] cfd md MD_B level 3

[DeviceC] cfd service-instance 3 ma-id string MA_B_1 md MD_B vlan 20

4. Device D的配置

[DeviceD] cfd md MD_A level 5

[DeviceD] cfd service-instance 1 ma-id string MA_A_1 md MD_A vlan 20

[DeviceD] cfd md MD_B level 3

[DeviceD] cfd service-instance 3 ma-id string MA_B_1 md MD_B vlan 20

5. Device E的配置

[DeviceE] cfd md MD_A level 5

[DeviceE] cfd service-instance 2 ma-id string MA_A_2 md MD_A vlan 30

[DeviceE] cfd md MD_B level 3

[DeviceE] cfd service-instance 4 ma-id string MA_B_2 md MD_B vlan 30

3.5.4  配置MEP

MEP ID分配如表3所示。

表3 MEP ID分配表

服务实例	设备	接口	MEP ID	MEP类型
1	DeviceA	Twenty-FiveGigE1/0/1	1001	内向MEP
	DeviceD	Twenty-FiveGigE1/0/2	1002	内向MEP
2	DeviceA	Twenty-FiveGigE1/0/2	2001	内向MEP
	DeviceE	Twenty-FiveGigE1/0/1	2002	内向MEP
3	DeviceB	Twenty-FiveGigE1/0/1	3001	内向MEP
	DeviceD	Twenty-FiveGigE1/0/1	3002	外向MEP
4	DeviceB	Twenty-FiveGigE1/0/1	4001	内向MEP
	DeviceE	Twenty-FiveGigE1/0/2	4002	外向MEP

 

1. Device A的配置

# 在Device A的服务实例1和2内分别配置MEP列表。

[DeviceA] cfd meplist 1001 1002 service-instance 1

[DeviceA] cfd meplist 2001 2002 service-instance 2

# 在接口Twenty-FiveGigE1/0/1上创建服务实例1内的内向MEP 1001。

[DeviceA] interface twenty-fivegige 1/0/1

[DeviceA-Twenty-FiveGigE1/0/1] cfd mep 1001 service-instance 1 inbound

[DeviceA-Twenty-FiveGigE1/0/1] quit

# 在接口Twenty-FiveGigE1/0/2上创建服务实例2内的内向MEP 2001。

[DeviceA] interface twenty-fivegige 1/0/2

[DeviceA-Twenty-FiveGigE1/0/2] cfd mep 2001 service-instance 2 inbound

[DeviceA-Twenty-FiveGigE1/0/2] quit

Device B、Device D和Device E的配置与Device A相似。

2. Device B的配置

[DeviceB] cfd meplist 3001 3002 service-instance 3

[DeviceB] cfd meplist 4001 4002 service-instance 4

[DeviceB] interface twenty-fivegige 1/0/1

[DeviceB-Twenty-FiveGigE1/0/1] cfd mep 3001 service-instance 3 inbound

[DeviceB-Twenty-FiveGigE1/0/1] cfd mep 4001 service-instance 4 inbound

[DeviceB-Twenty-FiveGigE1/0/1] quit

3. Device D的配置

[DeviceD] cfd meplist 1001 1002 service-instance 1

[DeviceD] cfd meplist 3001 3002 service-instance 3

[DeviceD] interface twenty-fivegige 1/0/2

[DeviceD-Twenty-FiveGigE1/0/2] cfd mep 1002 service-instance 1 inbound

[DeviceD-Twenty-FiveGigE1/0/2] quit

[DeviceD] interface twenty-fivegige 1/0/1

[DeviceD-Twenty-FiveGigE1/0/1] cfd mep 3002 service-instance 3 outbound

[DeviceD-Twenty-FiveGigE1/0/1] quit

4. Device E的配置

[DeviceE] cfd meplist 2001 2002 service-instance 2

[DeviceE] cfd meplist 4001 4002 service-instance 4

[DeviceE] interface twenty-fivegige 1/0/1

[DeviceE-Twenty-FiveGigE1/0/1] cfd mep 2002 service-instance 2 inbound

[DeviceE-Twenty-FiveGigE1/0/1] quit

[DeviceE] interface twenty-fivegige 1/0/2

[DeviceE-Twenty-FiveGigE1/0/2] cfd mep 4002 service-instance 4 outbound

[DeviceE-Twenty-FiveGigE1/0/2] quit

3.5.5  配置MIP的创建规则

# 在Device C的服务实例3内配置MIP的创建规则为Default规则。

[DeviceC] cfd mip-rule default service-instance 3

3.5.6  启用MEP的连续性检测功能

1. Device A的配置

# 在接口Twenty-FiveGigE1/0/1上开启服务实例1内MEP 1001的CCM报文发送功能。

[DeviceA] interface twenty-fivegige 1/0/1

[DeviceA-Twenty-FiveGigE1/0/1] cfd cc service-instance 1 mep 1001 enable

[DeviceA-Twenty-FiveGigE1/0/1] quit

# 在接口Twenty-FiveGigE1/0/2上开启服务实例2内MEP 2001的CCM报文发送功能。

[DeviceA] interface twenty-fivegige 1/0/2

[DeviceA-Twenty-FiveGigE1/0/2] cfd cc service-instance 2 mep 2001 enable

[DeviceA-Twenty-FiveGigE1/0/2] quit

Device B、Device D和Device E的配置与Device A相似。

2. Device B的配置

[DeviceB] interface twenty-fivegige 1/0/1

[DeviceB-Twenty-FiveGigE1/0/1] cfd cc service-instance 3 mep 3001 enable

[DeviceB-Twenty-FiveGigE1/0/1] cfd cc service-instance 4 mep 4001 enable

[DeviceB-Twenty-FiveGigE1/0/1] quit

3. Device D的配置

[DeviceD] interface twenty-fivegige 1/0/1

[DeviceD-Twenty-FiveGigE1/0/1] cfd cc service-instance 3 mep 3002 enable

[DeviceD-Twenty-FiveGigE1/0/1] quit

[DeviceD] interface twenty-fivegige 1/0/2

[DeviceD-Twenty-FiveGigE1/0/2] cfd cc service-instance 1 mep 1002 enable

[DeviceD-Twenty-FiveGigE1/0/2] quit

4. Device E的配置

[DeviceE] interface twenty-fivegige 1/0/1

[DeviceE-Twenty-FiveGigE1/0/1] cfd cc service-instance 2 mep 2002 enable

[DeviceE-Twenty-FiveGigE1/0/1] quit

[DeviceE] interface twenty-fivegige 1/0/2

[DeviceE-Twenty-FiveGigE1/0/2] cfd cc service-instance 4 mep 4002 enable

[DeviceE-Twenty-FiveGigE1/0/2] quit

3.6  验证配置

 

(1)     网络链路正常时

# 在Device A上查看服务实例1内MEP 1001的远端MEP的信息。

[DeviceA] display cfd remote-mep service-instance 1 mep 1001

MEP ID   MAC address      State        Time                  MAC status

1002     0010-fc04-6514   OK           2018/07/26 12:54:52   UP

结果显示远端MEP运行状态正常。

# 在Device A上启用环回功能，检查服务实例1内MEP 1001到MEP 1002的链路状况。

[DeviceA] cfd loopback service-instance 1 mep 1001 target-mep 1002

Loopback to MEP 1002 with the sequence number start from 1001-43404:

Reply from 0010-fc04-6514: sequence number=1001-43404 Time=5ms

Reply from 0010-fc04-6514: sequence number=1001-43405 Time=5ms

Reply from 0010-fc04-6514: sequence number=1001-43406 Time=5ms

Reply from 0010-fc04-6514: sequence number=1001-43407 Time=5ms

Reply from 0010-fc04-6514: sequence number=1001-43408 Time=5ms

Sent: 5        Received: 5        Lost: 0

结果显示服务实例1内的MEP 1001和MEP 1002间的链路无故障。

(2)     网络链路故障时

# 在Device A上查看服务实例1内MEP 1001的远端MEP的信息。

[DeviceA] display cfd remote-mep service-instance 1 mep 1001

MEP ID   MAC address      State        Time                  MAC status

1002     0010-fc04-6514   FAILED       2018/07/26 13:01:52   DOWN

结果显示远端MEP运行状态不正常。

# 在Device A上启用环回功能，检查服务实例1内MEP 1001到MEP 1002的链路状况。

[DeviceA] cfd loopback service-instance 1 mep 1001 target-mep 1002

Loopback to MEP 1002 with the sequence number start from 1001-43904:

Sent: 5        Received: 0        Lost: 5

结果显示服务实例1内的MEP 1001和MEP 1002间的链路存在故障。

# 先从小区域内排查故障位置，在Device B上开启链路跟踪功能，查找服务实例3内的MEP 3001到MEP 3002的路径。

[DeviceB] cfd linktrace service-instance 3 mep 3001 target-mep 3002

Linktrace to MEP 3002 with the sequence number 3001-43862:

MAC address               TTL     Last MAC         Relay action

0010-fc03-6513            63      0010-fc02-6512   MPDB

结果显示服务实例3内的MEP 3001仅收到MIP反馈的LTR报文，而未收到MEP3002（DeviceD的XGE1/0/1）反馈的LTR，从而可以初步判断Device C和Device D之间的链路发生故障。MD_B之外的网络就不用再进行故障检查，减少了故障定位的时间。

3.7  配置文件

·     Device A：

#

 cfd enable

 cfd md MD_A index 1 level 5

 cfd service-instance 1 ma-id string MA_A_1 ma-index 1 md MD_A vlan 20

 cfd meplist 1001 to 1002 service-instance 1

 cfd service-instance 2 ma-id string MA_A_2 ma-index 1 md MD_A vlan 30

 cfd meplist 2001 to 2002 service-instance 2

#

vlan 20

#

vlan 30

#

interface Twenty-FiveGigE1/0/1

 port link-mode bridge

 port access vlan 20

 cfd mep 1001 service-instance 1 inbound

 cfd cc service-instance 1 mep 1001 enable

#

interface Twenty-FiveGigE1/0/2

 port link-mode bridge

 port access vlan 30

 cfd mep 2001 service-instance 2 inbound

 cfd cc service-instance 2 mep 2001 enable

#

interface Twenty-FiveGigE1/0/3

 port link-mode bridge

 port link-type trunk

 port trunk permit vlan 20 30

·     Device B：

#

 cfd enable

 cfd md MD_B index 1 level 3

 cfd service-instance 3 ma-id string MA_B_1 ma-index 1 md MD_B vlan 20

 cfd meplist 3001 to 3002 service-instance 3

 cfd service-instance 4 ma-id string MA_B_2 ma-index 2 md MD_B vlan 30

 cfd meplist 4001 to 4002 service-instance 4

#

vlan 20

#

vlan 30

#

interface Twenty-FiveGigE1/0/1

 port link-mode bridge

 port link-type trunk

 port trunk permit vlan 20 30

 cfd mep 3001 service-instance 3 inbound

 cfd cc service-instance 3 mep 3001 enable

 cfd mep 4001 service-instance 4 inbound

 cfd cc service-instance 4 mep 4001 enable

#

interface Twenty-FiveGigE1/0/2

 port link-mode bridge

 port link-type trunk

 port trunk permit vlan 20

#

interface Twenty-FiveGigE1/0/3

 port link-mode bridge

 port link-type trunk

 port trunk permit vlan 30

·     Device C：

#

 cfd enable

 cfd md MD_B index 1 level 3

 cfd service-instance 3 ma-id string MA_B_1 ma-index 1 md MD_B vlan 20

 cfd mip-rule default service-instance 3

#

vlan 20

#

interface Twenty-FiveGigE1/0/1

 port link-mode bridge

 port link-type trunk

 port trunk permit vlan 20

#

interface Twenty-FiveGigE1/0/2

 port link-mode bridge

 port link-type trunk

 port trunk permit vlan 20

·     Device D：

#

 cfd enable

 cfd md MD_A index 1 level 5

 cfd md MD_B index 2 level 3

 cfd service-instance 1 ma-id string MA_A_1 ma-index 1 md MD_A vlan 20

 cfd meplist 1001 to 1002 service-instance 1

 cfd service-instance 3 ma-id string MA_B_1 ma-index 1 md MD_B vlan 20

 cfd meplist 3001 to 3002 service-instance 3

#

vlan 20

#

interface Twenty-FiveGigE1/0/1

 port link-mode bridge

 port link-type trunk

 port trunk permit vlan 20

 cfd mep 3002 service-instance 3 outbound

 cfd cc service-instance 3 mep 3002 enable

#

interface Twenty-FiveGigE1/0/2

 port link-mode bridge

 port access vlan 20

 cfd mep 1002 service-instance 1 inbound

 cfd cc service-instance 1 mep 1002 enable

·     Device E：

#

 cfd enable

 cfd md MD_A index 1 level 5

 cfd md MD_B index 2 level 3

 cfd service-instance 2 ma-id string MA_A_2 ma-index 1 md MD_A vlan 30

 cfd meplist 2001 to 2002 service-instance 2

 cfd service-instance 4 ma-id string MA_B_2 ma-index 2 md MD_B vlan 30

 cfd meplist 4001 to 4002 service-instance 4

#

vlan 30

#

interface Twenty-FiveGigE1/0/1

 port link-mode bridge

 port access vlan 30

 cfd mep 2002 service-instance 2 inbound

 cfd cc service-instance 2 mep 2002 enable

#

interface Twenty-FiveGigE1/0/2

 port link-mode bridge

 port link-type trunk

 port trunk permit vlan 30

 cfd mep 4002 service-instance 4 outbound

 cfd cc service-instance 4 mep 4002 enable