Cisco ACI SPAN session not working in both directions

[chrisdaly]

I have a pair of SPAN sessions on 2 ACI Leaf switches but the traffic only appears to be getting captured in 1 direction.  I checked the SPAN configuration and it does specify "Both" in terms of direction.  Anyone have this issue?  It's an older version of ACI (v2) so it could be some kind of bug - just wanted to see if I've missed something in the config.  It's a SPAN between ports on the same Leaf switches.

[chrisdaly]

Just fyi - actual version is 2.2(1o)

[Sergiu.Daniluk]

Hi @chrisdaly 

Just to clarify:

• is it Local SPAN or ERSPAN?
• which traffic is seen to be unidirectional: unicast, broadcast, multicast, all traffic?
• which platform you have as ACI leaf?

Cheers,

Sergiu

[chrisdaly]

Thanks for responding!

-Local SPAN session on Leaf switches

-Looks like all traffic but unicast for sure

-Leaf switches are N9K-C93180YC-EX - firmware n9000-12.2(1o)

[Sergiu.Daniluk]

Hi,

How many SPAN sessions you have in total on your Leaf switch?

Total number of supported sessions for ALE based switches - including N9K-C93180YC-EX, is:

• 4 uni-directional or 2 bi-directional infra/tenant sessions

• 4 uni-directional or 2 bi-directional fabric sessions

Cheers,

Sergiu

[chrisdaly]

1 local SPAN on each Leaf switch - SPANs are configured under access policies.  Are those limits per Fabric, tenant or per Leaf?

[Sergiu.Daniluk]

The limit is the same as the previously mentioned. Hmm well what you have there sounds either like a bug or a limitation.

I was not able to find anything mentioned in the guidelines and limitations. And reg bugs, this one seems to be affecting your version:

CSCvc11053 - SPAN not capturing incoming traffic on 2nd generation ASIC ACI LEAF


Symptom:
Incoming traffic is not captured by SPAN or ERSPAN.
This is a current limitation in 2nd generation ASIC ACI LEAF (N9K-C93180YC-EX and 93108TC-EX).

Conditions:
When SPAN or ERPSAN source is configured using a individual port, which is a member of a Port-Channel or a vPC, on 2nd generation ASIC ACI LEAF.

Workaround:
None.
For Local SPAN : Please configure PC itself.  If you want to SPAN the vPC, please choose the "VPC Component PC" option.
For ERSPAN      : Please configure PC itself in case of PC, please configure vPC itself in case of vPC as a source instead of its member port.

Is it applicable for you? Do you span a individual interface part of a PC?

Regards,

Sergiu