cfm md
Function
The cfm md command creates an MD and displays the MD view, or displays the view of an existing MD.
The undo cfm md command deletes an MD.
Format
cfm md md-name [ format { no-md-name | dns dns-md-format-name | mac-address mac-md-format-name | string string-md-format-name } ] [ level level ]
undo cfm md [ md-name ]
Parameters
Parameter |
Description |
Value |
|---|---|---|
md md-name |
Specifies the name of an MD. |
The value is a string of 1 to 43 case-sensitive characters without spaces, hyphens (-), and question marks (?). The name of an MD on a device must be unique. NOTE:
When double quotation marks are used around the string, spaces are allowed in the string. |
no-md-name |
Indicates that the MA ID field of a sent packet does not contain an MD name. |
- |
dns dns-md-format-name |
Specifies the DNS name used as the MD name carried in packets. |
The value is a string of 1 to 43 case-sensitive characters without spaces, hyphens (-), and question marks (?). |
mac-address mac-md-format-name |
Specifies an MD name carried in packets, in the format of H-H-H:U<0-65535>, for example, 0001-0001-0001:1. |
The value is a string of 1 to 43 case-sensitive characters without spaces, hyphens (-), and question marks (?). |
string string-md-format-name |
Specifies an ASCII MD name. |
The value is a string of 1 to 43 case-sensitive characters without spaces, hyphens (-), and question marks (?). |
level level |
Specifies the level of an MD. |
The value is an integer that ranges from 0 to 7. A larger value indicates a higher MD priority. The default value is 0. |
Usage Guidelines
Usage Scenario
To configure CFM to identify and locate faults on links, use this command to create an MD.
Precautions
All the CFM-enabled devices of an ISP can be added to the same MD.
When 802.1ag packets in a low-level MD enter a high-level MD, the 802.1ag packets will be discarded. 802.1ag packets in a high-level MD can traverse a low-level MD. 802.1ag packets in an MD cannot traverse the MD of the same level.
Only IEEE Standard 802.1ag-2007 supports format, no-md-name, dns dns-md-format-name, mac-address mac-md-format-name, and string string-md-format-name.
The MD name format can be specified during the MD configuration, as defined in IEEE Standard 802.1ag-2007. Each MD can be configured with only one name format and one level. You can use the cfm md command to enter the view of the existing MD but cannot change the name format and level of the existing MD. To change the name format and level of the existing MD, delete the MD and then use the cfm md command to create a new MD.
As defined in IEEE 802.1ag Draft 7, after creating an MD, you cannot use the cfm md command to change the level of the MD. To change the level of the MD, you need to delete the MD and then create an MD again.
A maximum of 16 MDs can be created on a device.
When an MD is deleted, a device automatically deletes all the configurations of MAs, MEPs, MIPs, and RMEPs within the MD.
The MA, MEP, and RMEP must be created within an MD, so you must create an MD before creating the MA, MEP, and RMEP.
Prerequisites
CFM has been enabled globally using the cfm enable (system view) command.
Example
# Create an MD named mdcustomer at level 4.
<HUAWEI> system-view [HUAWEI] cfm enable [HUAWEI] cfm md mdcustomer level 4
<HUAWEI> system-view [HUAWEI] undo cfm md mdcustomer Warning: Deleting the MD(s) will delete all information about the MA(s). Continue?[Y/N]:y [HUAWEI] cfm md mdcustomer level 6
<HUAWEI> system-view [HUAWEI] cfm enable [HUAWEI] cfm md mdcustomer format no-md-name level 4