Extreme X460 - X670 CFM | Hardware vs Software Session Type

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  • Updated 10 months ago
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I've configured a back to back CFM domain between an X460-48x and an X670V-48x, created the association and added the remote rmep and lmep.

X670V-48x


Review configuration below: 
create cfm domain string "Access" md-level 2
configure cfm domain "Access" add association string "link1" vlan "aggr-sw1-to-acc-sw1"
configure cfm domain "Access" association "link1" destination-mac-type multicast
configure cfm domain "Access" association "link1" transmit-interval 1000
configure cfm domain "Access" association "link1" add remote-mep 10 mac-address 00:04:96:99:37:df
configure cfm domain "Access" association "link1" ports 46 add end-point down 20
configure cfm domain "Access" association "link1" ports 46 end-point down transmit-interval 1000
configure cfm domain "Access" association "link1" ports 46 end-point down enable
configure cfm domain "Access" association "link1" ports 46 end-point down ccm enable
configure cfm domain "Access" association "link1" ports 46 end-point down sender-id-ipaddress disable
configure cfm domain "Access" association "link1" ports 46 end-point down add group "LinkA-LinkB"
configure cfm group "LinkA-LinkB" add rmep 10


X460-48x

create cfm domain string "Access" md-level 2
configure cfm domain "Access" add association string "link1" vlan "aggr-sw1-to-acc-sw1"
configure cfm domain "Access" association "link1" destination-mac-type multicast
configure cfm domain "Access" association "link1" transmit-interval 1000
configure cfm domain "Access" association "link1" add remote-mep 20 mac-address 00:04:96:97:e6:76
configure cfm domain "Access" association "link1" ports 51 add end-point down 10
configure cfm domain "Access" association "link1" ports 51 end-point down transmit-interval 1000
configure cfm domain "Access" association "link1" ports 51 end-point down enable
configure cfm domain "Access" association "link1" ports 51 end-point down ccm enable
configure cfm domain "Access" association "link1" ports 51 end-point down sender-id-ipaddress disable
configure cfm domain "Access" association "link1" ports 51 end-point down add group "LinkA-LinkB"
configure cfm group "LinkA-LinkB" add rmep 20


Whilst viewing the "session counters missed-hellos", the x670 displays it's in a Software session type compared to the X460 displaying it's in a hardware session type.

Based on the documentation, for a MP to be processed in hardware it requires 2 things: 

1: The MP must be of type "Down MEP".
2: The remote mep must also be statically set rather than dynamic. 

I've met both of these requirements.


* X670V-48x # show cfm session counters missed-hellos no-refresh 
================================================================================
Session ID        Port   Remote End-Point  Interval  Missed  Missed   Down Flags
                         MAC Address        (msec)     Once   Twice             
================================================================================
2-101-20-10       46     00:04:96:99:37:df     1000      17       0      0  DSAs
================================================================================
Session ID: MD Level-VLAN ID-Local MEP ID-Remote MEP ID
Flags: Maintenance Point: (U) Up End-Point, (D) Down End-Point
       Session Type: (S) Software, (H) Hardware
       Status: (A) Active, (I) Inactive
       Remote End-Point MAC Address: (d) dynamic, (s) static


X460-48x #  show cfm session counters missed-hellos no-refresh 
================================================================================
Session ID        Port   Remote End-Point  Interval  Missed  Missed   Down Flags
                         MAC Address        (msec)     Once   Twice             
================================================================================
2-101-10-20       51     00:04:96:97:e6:76     1000    ---     ---       0  DHAs
================================================================================
Session ID: MD Level-VLAN ID-Local MEP ID-Remote MEP ID
Flags: Maintenance Point: (U) Up End-Point, (D) Down End-Point
       Session Type: (S) Software, (H) Hardware
       Status: (A) Active, (I) Inactive
       Remote End-Point MAC Address: (d) dynamic, (s) static


This is clearly not working...


Please assist. 

Thanks!
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Justin Tylcoat

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Posted 11 months ago

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Jacob, Praveen, Employee

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We shall this review this and get back to you Justin. I would also suggest you open a case with GTAC. 
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Justin Tylcoat

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Hi Jacob - Any feedback?
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Erik Auerswald, Embassador

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Hi,

I tried to find out which ExtremeSwitching platforms support CFM processing in hardware, but did not find any conclusive information. :-(

Anyway, my understanding is that this feature uses hardware capabilities similar to BFD, and for BFD there is a GTAC Knowledge article with title BFD Hardware Assist feature for 670-G2 that says only the X460-G2 supports it in hardware. The current documentation (OAM -> BFD -> Limitations) extends this to X460-G2, X690, and X870 switches (the 16.2 documentation lists just X460-G2 switches).

Thus I would expect that the X670V does not support hardware MEPs and thus always uses software MEPs.

If anybody has additional information, please share. :-)

Thanks,
Erik