Preview Tool

Cisco Bug: CSCuo68435 - On N6k programming of updated Fabricpath FWD entries to hardware delayed

Last Modified

Jan 30, 2017

Products (7)

  • Cisco Nexus 6000 Series Switches
  • Cisco Nexus 5548P Switch
  • Cisco Nexus 5596UP Switch
  • Cisco Nexus 6004 Switch
  • Cisco Nexus 6001 Switch
  • Cisco Nexus 5672UP Switch
  • Cisco Nexus 5548UP Switch

Known Affected Releases

6.0(2)N2(3) 7.0(1)N1(1) 7.1(0)N1(0.197)

Description (partial)

On N6k devices when Fabricpath topology is updated, programming of the updated forwarding entries to hardware is being delayed by 30-60 seconds. As a result some traffic flows might experience drops during that time. The issue recovers by itself after the period of 30-60 seconds.

Executing "show platform info pif all | inc drop", "clear mac address-table dynamic" or "show running-config" commands during the issue on the N6k device with staled Fabricpath forwarding entries in hardware recovers the setup from the issue immediately.

The issue might be seen on N6k Fabricpath spine devices on Fabricpath topology change event. This is seen in case there is N5k VPC+ setup connected to the N6k Fabricpath setup, and the VPC peer-link on the N5k VPC+ setup becomes disabled. The traffic which was previously sent by N6k FP switch towards N5k Secondary VPC+ switch should be shifted to the N5k Primary VPC+ switch, but this transition is delayed by 30-60 seconds.

The problem is seen when there are active VPC orphan ports on the N5k Secondary VPC+ switch. If the orphan port is manually disabled by "shutdown" command, or "vpc orphan-port suspend" command is used - the issue disappears.
Bug details contain sensitive information and therefore require a 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.