Guest

Preview Tool

Cisco Bug: CSCuo56852 - MAC Address is not synced properly across DFCs in VSS

Last Modified

Nov 27, 2020

Products (1)

  • Cisco Catalyst 6000 Series Switches

Known Affected Releases

15.1(0.0.0) 15.1(2)SY5.9

Description (partial)

Symptom:
When mac address is moved in between WS-X6904  line cards belonging to different VSS nodes  -  DFC tcam are not updated with this change 

example
Mac address 885a.921b.6ec8 has moved in between Po 3 and Po3

#show mac address-table address  885a.921b.6ec8      vlan 3002

Legend: * - primary entry
        age - seconds since last seen
        n/a - not available
        S - secure entry
        R - router's gateway mac address entry
        D - Duplicate mac address entry

Displaying entries from DFC switch [1] linecard [1]:

     vlan   mac address    type   learn    age                 ports
----+----+---------------+-------+-----+----------+-----------------------------
     3002 885a.921b.6ec8  dynamic  Yes       15     Po3


Displaying entries from DFC switch [1] linecard [2]:

     vlan   mac address    type   learn    age                 ports
----+----+---------------+-------+-----+----------+-----------------------------
     3002 885a.921b.6ec8  dynamic  Yes      160     Po3


Displaying entries from DFC switch [1] linecard [3]:

     vlan   mac address    type   learn    age                 ports
----+----+---------------+-------+-----+----------+-----------------------------
*    3002 885a.921b.6ec8  dynamic  Yes        0     Po2    <<<< Traffic seen on new port Po2 when all other cards see it on Po3


Displaying entries from active supervisor:

     vlan   mac address    type   learn    age                 ports
----+----+---------------+-------+-----+----------+-----------------------------
     3002 885a.921b.6ec8  dynamic  Yes      160     Po3


Displaying entries from DFC switch [2] linecard [1]:

     vlan   mac address    type   learn    age                 ports
----+----+---------------+-------+-----+----------+-----------------------------
     3002 885a.921b.6ec8  dynamic  Yes      165     Po3


Displaying entries from DFC switch [2] linecard [2]:

     vlan   mac address    type   learn    age                 ports
----+----+---------------+-------+-----+----------+-----------------------------
     3002 885a.921b.6ec8  dynamic  Yes      165     Po3


Displaying entries from DFC switch [2] linecard [3]:

     vlan   mac address    type   learn    age                 ports
----+----+---------------+-------+-----+----------+-----------------------------
*    3002 885a.921b.6ec8  dynamic  Yes       10     Po3


Displaying entries from DFC switch [2] linecard [4]:

     vlan   mac address    type   learn    age                 ports
----+----+---------------+-------+-----+----------+-----------------------------
     3002 885a.921b.6ec8  dynamic  Yes      155     Po3


Displaying entries from standby supervisor:

     vlan   mac address    type   learn    age                 ports
----+----+---------------+-------+-----+----------+-----------------------------
     3002 885a.921b.6ec8  dynamic  Yes      150     Po3

Issue is seen till old card will age out the mac address. Then all other cards are getting in sync with new line card.

Conditions:
VSS build using WS-X6904 with DFC running15.1(1)SY2

Issue is not seen when the first packet  sent on new port /line card is Gratuitous ARP.

If we send ping or any other traffic the issue is present.
Bug details contain sensitive information and therefore require a Cisco.com account to be viewed.

Bug Details Include

  • Full Description (including symptoms, conditions and workarounds)
  • Status
  • Severity
  • Known Fixed Releases
  • Related Community Discussions
  • Number of Related Support Cases
Bug information is viewable for customers and partners who have a service contract. Registered users can view up to 200 bugs per month without a service contract.