Guest

Preview Tool

Cisco Bug: CSCvs90354 - N3000 not accepts multicast max-limit with 8000 tcam region carving with no available tcam space

Last Modified

Feb 27, 2020

Products (1)

  • Cisco Nexus 3000 Series Switches

Known Affected Releases

6.0(2)

Description (partial)

Symptom:
N3000 not accepts multicast max-limit with 8000 tcam region carving with no available tcam space

Conditions:
This is a specific issue with 6.0(2) images. Please suggest customer to move to latest converged releases.
 
The Unicast Ipv4 Host table, Unicast Ipv6 host table and Multicast table sharing same memory region in ASIC. The maximum entries available in this region is 16384.
 
The entry consumption for each cases as below:
Unicast Ipv4 entry ? 1 entry
Unicast Ipv6 entry ? 2 entries
Multicast Ipv4 entry ? 2 entries
Multicast Ipv6 entries ? 4 entries
 
So in 6.0(2) images, we have the below check before setting the multicast max-limit
 
(16384 ? (current IPv4 Unicast host entries + Current Ipv6 Unicast host entries * 2)) <= This should be less than or equal to the (2 * new_limit)(in customer scenario, it is 16000(2 * 8000)).
 
Since customer devices are having good number of Host table entries(around 2K), so the above check is failing and CLI returning the error.
 
In the latest branches, the design is different and this check is not available, and once any entries cross its specified limit, system throws MAX-LIMIT syslogs.
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.