20• The port is configured as a MIP or an inward-facing MEP that can still receive and send CFDmessages except CCM messages.For more information about the spanning tree feature, see Layer 2—LAN Switching Configuration Guide.Configuring basic CFD settingsThis section provides procedures for configuring basic CFD settings.Enabling CFDEnable CFD before you perform other configuration tasks.To enable CFD on a device:Step Command Remarks1. Enter system view. system-view N/A2. Enable CFD. cfd enable By default, CFD is disabled.Configuring the CFD protocol versionThree CFD protocol versions are available: IEEE 802.1ag draft5.2 version, IEEE 802.1ag draft5.2 interimversion, and IEEE 802.1ag standard version.Devices in the same MD must use the same CFD protocol version. Otherwise, they cannot exchange CFDprotocol packets.If an MD is created by using the cfd md command or automatically generated by using the cfdservice-instance maid format command on a device, you cannot switch between the standard versionand draft5.2 version (or draft5.2 interim version). However, you can switch between the draft5.2 versionand draft5.2 interim version. This restriction does not apply to the device without an MD configured.To configure the CFD protocol version:Step Command Remarks1. Enter system view. system-view N/A2. Configure the CFD protocolversion.cfd version { draft5 | draft5-plus |standard }Optional.By default, CFD uses the standardversion of IEEE 802.1ag.Configuring service instancesBefore configuring the MEPs and MIPs, first configure service instances. A service instance is a set ofservice access points (SAPs), and belongs to an MA in an MD.A service instance is indicated by an integer to represent an MA in an MD. The MD and MA define thelevel and VLAN attribute of the messages handled by the MPs in a service instance.Service instances fall into two types:• Service instance with the MD name, which takes effect in any version of CFD.
