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Question

Extreme X460 - X670 CFM | Hardware vs Software Session Type


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!

3 replies

Userlevel 3
We shall this review this and get back to you Justin. I would also suggest you open a case with GTAC.
Hi Jacob - Any feedback?
Userlevel 7
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

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