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Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 57 Configuring Ethernet OAM and CFM
Configuring Ethernet CFM
CFM Unicast packets (Loopback Messages and Traceroute Reply), are not allowed on Down MEP
on STP blocked ports. The blocked port cannot respond to ping and traceroute. You must configure
a port MEP at a lower level than any service (VLAN) MEPs on an interface.
An 802.1Q (QinQ) tunnel port can be an Up MEP or a port MEP.
A QinQ port cannot be a Down MEP or a MIP; you can configure the port as a MIP, but it is not
active or visible in traceroute. Port MEP frames received on a QinQ interface are not tunneled and
are processed locally.
CFM on a C-VLAN is supported on Traditional and Selective QinQ and not supported on
One-to-One VLAN Mapping on Trunk ports.
Do not configure a port with tunnel mode using the native VLAN as the S-VLAN or the C-VLAN.
For port MEP on a QinQ port, do not enter the vlan dot1q tag native global configuration command
to enable tagging on native VLAN frames.
If you are running CFM draft 1 and upgrade to a software version that supports CFM draft 8.1, the
switch silently drops the draft 1 configuration on draft 8.1 image. Some of the CLIs have been
changed from draft1 to draft8.1. You need to reconfigure all the required configurations on draft 8.1
image.
Configuring the CFM Domain
To configure the Ethernet CFM domain, configure a service to connect the domain to a VLAN, or
configure a port to act as a MEP, perform this task. You can also enter the optional commands to
configure other parameters, such as continuity checks.
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 ethernet cfm ieee A must have configuration for draft 8.1. This is required to
be configured before any other configuration.
Step 3 ethernet cfm global Globally enable Ethernet CFM on the switch.
Step 4 ethernet cfm traceroute cache [size entries |
hold-time minutes](Optional) Configure the CFM traceroute cache. You can
set a maximum cache size or hold time.
(Optional) For size, enter the cache size in number of
entry lines. The range is from 1 to 4095; the default is
100 lines.
(Optional) For hold-time, enter the maximum cache
hold time in minutes. The range is from 1 to 65535; the
default is 100 minutes.
Step 5 ethernet cfm mip auto-create level level-id
vlan vlan-id (Optional) Configure the switch to automatically create
MIPs for VLAN IDS that are not associated with specific
maintenance associations at the specified level. The level
range is 0 to 7.
Note Configure MIP auto-creation only for VLANs that
MIPs should monitor. Configuring for all VLANs
can be CPU and memory-intensive.
Step 6 ethernet cfm mip filter (Optional) Enable MIP filtering, which means that all CFM
frames at a lower level are dropped. The default is disabled.