Date created: 08/26/19 20:32:24. Last modified: 09/02/19 08:08:28

Ethernet CFM CCM/DMM over Pseudowire Inter-Op

Overview

In the example topology below two pseudowires are configured between the Huaweu CX600 device and Cisco ASR9904 device (one of them is a backup pseudowire). The Alcatel / Nokia SR-7750 is acting as a pseudowire stitching PE.

  +---------------+      +-----------------+                 +-----------------+
| | | | | |
| me1 |------+ sr15 +-----------------+ ar0 |
| 10.0.255.1 | | 10.0.34.250/32 | | 10.0.255.40/32 |
+---------------+ +-----------------+ +--------+--------+
| Te0/0/0/2/1.3001|
1G:0/3/22|

CFM domain 1 exists between the ASR9904 and the 7750 (one of the two stitched pseudowires), and it exists between the 7750 and the CX600 (the other of the two stitched pseudowires). Domain 2 exists between the ASR9904 and the CX600 (the two endpoints of the end-to-end pseudowire service). This allows for domain 1 CCM messages to be sent to check connectivity separately for each half of the stitched pseudowire service and for domain 2 CCM messages to be sent to check the end-to-end pseudowire service.

The CFM topology lis shown in the diagram below:

   MEP ID 3                           MEP ID 2                           MEP ID 1
88:cf:98:bb:0d:47 0c:a4:02:1c:78:01 6c:8b:d3:3f:e2:95
+---------------+ +---------------+ +---------------+
| | | | | |
| me1 +-----------------+ sr15 +------------------+ ar0 |
| | | | | |
+---------------+ +---------------+ +---------------+

+-----------------+ +------------------+
Domain 1 Domain 1


+----------------------------------------------------+
Domain 2

The configuration implemented sends CCM messages from the ASR9904 to SR15 and ME1 every 1 minute. However, it is also possible to manually "ping" the devices at any time using DMR/DMR or LMR/LMM messages (depending on what the device supports).

 

Configs

Huawei CX600 "ME1"
Nokia SR-7705 "SR15"
Cisco ASR9904 "AR0"

 

CFM Domain 1 / Level 1

On the 7750 stitching-PE it can be seen that the MEP ID (1) and MAC address (6c:8b:d3:3f:e2:95) of the ASR9904 has been learnt at domain 1 / level 1 over the active pseudowire:

*A:sr15 # show eth-cfm association 212 detail 
-------------------------------------------------------------------------------
Domain 1 Associations:
-------------------------------------------------------------------------------
Md-index : 1 Ma-index : 212
Name Format : icc-based CCM-interval : 60
Auto Discover : True CCM-hold-time : n/a
Name : ATest98023001
Permission : sendIdNone
Bridge-id : 10105 MHF Creation : defMHFnone
PrimaryVlan : 0 Num Vids : 0
MIP LTR Priority : 7
Total MEP Count : 2
Remote Mep Id : 1 (AutoDiscovered) Remote MAC Addr : default
-------------------------------------------------------------------------------

*A:sr15 # show eth-cfm learned-remote-mac domain 1 association 212
=======================================================================
Eth-CFM Learned Remote MEPID MAC Address
=======================================================================
MdIndex MaIndex L-MepId R-MepId Learned Remote MAC Stale Updated
-----------------------------------------------------------------------
1 212 2 1 6c:8b:d3:3f:e2:95 False False
=======================================================================

On the ASR9904 it can be seen that the remote MEP (2) and MAC address (0c:a4:02:1c:78:01) of the 7750 have been learnt at domain 1 / level 1 over the active pseudowire:

RP/0/RSP0/CPU0:ar0-ws #show ethernet cfm peer meps interface Te0/0/0/2/1.3001 domain 1 detail 
Domain 1 (level 1), Service L2VPN_PW_989903001
Up MEP on TenGigE0/0/0/2/1.3001 MEP-ID 1
================================================================================
Peer MEP-ID 2, MAC 0ca4.021c.7801
CFM state: Ok, for 21:41:06
Received CCM handling offloaded to software
CCMs received: 1303
Out-of-sequence: 0
Remote Defect received: 91
Wrong level: 0
Cross-connect (wrong MAID): 2
Wrong interval: 0
Loop (our MAC received): 0
Config (our ID received): 0
Last CCM received:
Level: 1, Version: 0, Interval: 1min
Sequence number: 0, MEP-ID: 2
MAID: NULL, ICC-based: ATest98023001

The 7750 is able to “ping” the ASR9904 over the active pseudowire using the remote MEP ID or MAC address. The “oam eth-cfm two-way-delay-test” command uses CFM DMRs/DMMs:

*A:sr15 # oam eth-cfm two-way-delay-test 6c:8b:d3:3f:e2:95 mep 2 domain 1 association 212 
Two-Way-Delay-Test Response:
Delay 76 microseconds Variation 5 microseconds

*A:sr15 # oam eth-cfm two-way-delay-test remote-mepid 1 mep 2 domain 1 association 212
Two-Way-Delay-Test Response:
Delay 74 microseconds Variation 2 microseconds

The ASR9904 is able to “ping” the 7750 over the active pseudowire using the remote MEP ID or MAC address. The “ping ethernet cfm” command uses CFM LBRs/LBMs:

RP/0/RSP0/CPU0:ar0 #ping ethernet cfm domain 1 service L2VPN_PW_989903001 mac-address 0ca4.021c.7801 source interface Te0/0/0/2/1.3001
Type escape sequence to abort.
Sending 5 CFM Loopbacks, timeout is 2 seconds -
Domain 1 (level 1), Service L2VPN_PW_989903001
Source: MEP ID 1, interface TenGigE0/0/0/2/1.3001
Target: 0ca4.021c.7801 (no MEP ID specified):
Running (5s) ...
Success rate is 100.0 percent (5/5), round-trip min/avg/max = 7/15/17 ms
Out-of-sequence: 0.0 percent (0/5)
Bad data: 0.0 percent (0/5)
Received packet rate: 1.3 pps

RP/0/RSP0/CPU0:ar0-ws #ping ethernet cfm domain 1 service L2VPN_PW_989903001 mep-id 2 source mep-id 1 interface Te0/0/0/2/1.3001
Type escape sequence to abort.
Sending 5 CFM Loopbacks, timeout is 2 seconds -
Domain 1 (level 1), Service L2VPN_PW_989903001
Source: MEP ID 1, interface TenGigE0/0/0/2/1.3001
Target: 0ca4.021c.7801 (MEP ID 2):
Running (5s) ...
Success rate is 100.0 percent (5/5), round-trip min/avg/max = 4/10/16 ms
Out-of-sequence: 0.0 percent (0/5)
Bad data: 0.0 percent (0/5)
Received packet rate: 1.3 pps

 

CFM Domain 2 / Level 2

On the CX600 it can be seen that the MEP ID (1) and MAC address (6c:8b:d3:3f:e2:95) of the ASR9904 have been learnt at domain 2 / level 2 over the active pseudowire:

<me1 >display cfm remote-mep md test
The total number of RMEPs is : 1
The status of RMEPs : 1 up, 0 down, 0 disable
--------------------------------------------------
MD Name : test
Level : 2
MA Name : 40
RMEP ID : 1
VLAN ID : --
VSI Name : --
L2VC ID : 989903001 raw
L2VPN Name : --
CE ID : --
CE Offset : --
L2TPV3 Tunnel Name : --
L2TPV3 Local Connection Name : --
MAC : 6c8b-d33f-e295
CCM Receive : enabled
Trigger-If-Down : disabled
CFM Status : up
Alarm Status : none
Interface TLV : up
Port Status TLV : up

On the ASR9904 it can be seen that the remote MEP (3) and MAC address (88:cf:98:bb:0d:47) have been learnt at domain 2 / level 2 over the active pseudowire from the CX600:

RP/0/RSP0/CPU0:ar0 #show ethernet cfm peer meps interface Te0/0/0/2/1.3001 domain 2 detail 
Domain 2 (level 2), Service L2VPN_PW_989903001
Up MEP on TenGigE0/0/0/2/1.3001 MEP-ID 1
================================================================================
Peer MEP-ID 3, MAC 88cf.98bb.0d47
CFM state: Ok, for 01:22:09
Received CCM handling offloaded to software
CCMs received: 1090
Out-of-sequence: 0
Remote Defect received: 0
Wrong level: 0
Cross-connect (wrong MAID): 0
Wrong interval: 0
Loop (our MAC received): 0
Config (our ID received): 0
Last CCM received:
Level: 2, Version: 0, Interval: 1min
Sequence number: 0, MEP-ID: 3
MAID: NULL, ICC-based: ATest98053001

The CX600 is able to ”ping” the ASR9904 over the active pseudowire using the remote MEP ID or MAC address. This “ping mac-8021ag” commands uses CFM LBRs/LBMs:

<me1 >ping mac-8021ag mep mep-id 3 md test ma 40 remote-mep mep-id 1 
Pinging 6c8b-d33f-e295 with 95 bytes of data:
Reply from 6c8b-d33f-e295: bytes = 95, time < 1ms
Reply from 6c8b-d33f-e295: bytes = 95, time < 1ms
Reply from 6c8b-d33f-e295: bytes = 95, time < 1ms
Reply from 6c8b-d33f-e295: bytes = 95, time < 1ms
Reply from 6c8b-d33f-e295: bytes = 95, time < 1ms
Packets: Sent = 5, Received = 5, Lost = 0 (0% loss)
Minimum = 1ms, Maximum = 1ms, Average = 1ms

<me1 >ping mac-8021ag mep mep-id 3 md test ma 40 mac 6c8b-d33f-e295
Pinging 6c8b-d33f-e295 with 95 bytes of data:
Reply from 6c8b-d33f-e295: bytes = 95, time < 1ms
Reply from 6c8b-d33f-e295: bytes = 95, time < 1ms
Reply from 6c8b-d33f-e295: bytes = 95, time < 1ms
Reply from 6c8b-d33f-e295: bytes = 95, time < 1ms
Reply from 6c8b-d33f-e295: bytes = 95, time < 1ms
Packets: Sent = 5, Received = 5, Lost = 0 (0% loss)
Minimum = 1ms, Maximum = 1ms, Average = 1ms

The ASR9904 is able to “ping” the CX600 over the active pseudowire using the remote MEP ID or MAC address. The “ping ethernet cfm” command uses CFM LBRs/LBMs:

RP/0/RSP0/CPU0:ar0 #ping ethernet cfm domain 2 service L2VPN_PW_989903001 mac-address 88cf.98bb.0d47 source mep-id 1 interface Te0/0/0/2/1.3001
Type escape sequence to abort.
Sending 5 CFM Loopbacks, timeout is 2 seconds -
Domain 2 (level 2), Service L2VPN_PW_989903001
Source: MEP ID 1, interface TenGigE0/0/0/2/1.3001
Target: 88cf.98bb.0d47 (no MEP ID specified):
Running (5s) ...
Success rate is 100.0 percent (5/5), round-trip min/avg/max = 2/3/8 ms
Out-of-sequence: 0.0 percent (0/5)
Bad data: 0.0 percent (0/5)
Received packet rate: 1.3 pps

RP/0/RSP0/CPU0:ar0 #ping ethernet cfm domain 2 service L2VPN_PW_989903001 mep-id 3 source mep-id 1 interface Te0/0/0/2/1.3001
Type escape sequence to abort.
Sending 5 CFM Loopbacks, timeout is 2 seconds -
Domain 2 (level 2), Service L2VPN_PW_989903001
Source: MEP ID 1, interface TenGigE0/0/0/2/1.3001
Target: 88cf.98bb.0d47 (MEP ID 3):
Running (5s) ...
Success rate is 100.0 percent (5/5), round-trip min/avg/max = 2/2/5 ms
Out-of-sequence: 0.0 percent (0/5)
Bad data: 0.0 percent (0/5)
Received packet rate: 1.3 pps