Guest

Preview Tool

Cisco Bug: CSCtc78938 - Traffic converges partially after issu runversion for ATMoMPLS

Last Modified

Jan 31, 2017

Products (1)

  • Cisco ASR 1000 Series Aggregation Services Routers

Known Affected Releases

12.2(33)XN

Description (partial)

Symptoms: After doing a 6RU Superpackage ISSU on the MCP PE router, some
 ATMoMPLS pseudowires fail to be downloaded to FMAN-FP and QFP, hence all
 traffic sent through these pseudowires are dropped. 
 
 In the failed state, the router has the following symptoms:
 
 1. The show platform hardware qfp active stat drop clea | ex
 _0_ command shows packets dropped in the "Disabled" row.
 
 2. The show platform hardware qfp active interface all statistics
 drop_summary cl command shows some ATM interfaces have packet drops.
 
 3. The show platform hardware qfp active feature xcon cl
 int command shows that no xconnect is configured on the affected ATM
 interface on QFP side: 
 
 1k-60-2#show plat hard qfp act feat xcon cl int ATM0/1/0.1129
 % Error: Unable to get xconnect config interface=ATM0/1/0.1129
 
 4. The show platform software atom fp active xconnect
 command shows fewer entries than show platform software atom rp active
 xconnect:
 
 1k-60-2#sh platform software atom fp active xconnect
 ATOM/Local Cross-connect table, Number of entries: 7712
 
 1k-60-2#sh platform software atom rp active xconnect
 Number of xconnect entries: 7736
 
 Conditions: The symptom is caused by ATM PVC being downloaded to FMAN after
 xconnect is downloaded due to the long delay in setting up ATM PVC in IOSD shim
 layer. The issue only occurs with ATMoMPLS, and only when ATM PVC is being set
 up with xconnect pre-configured on it. An example scenario is ISSU.
 
 Workaround 1: When the issue occurs, remove xconnect and then add back xconnect
 on these affected ATM interfaces. You can find out these interfaces with the
 show platform hardware qfp active interface all statistics
 drop_summary cl command when traffic is on. Another way to find the
 affected interfaces is to run the show platform hardware capacity
 active feat xcon cl int INTERFACE_NAME command. If it has the
 following sample output while it has xconnect configured, then it is affected:
 
 1k-60-2#show plat hard cpp act feat xcon cl int ATM0/1/0.1129
 % Error: Unable to get xconnect config interface=ATM0/1/0.1129
 
 Workaround 2: When the issue occurs, run clear xconnect all
 which will re-provision xconnect. This command may take several minutes to
 fully re-provision xconnect on all configured interfaces.
 
 Workaround 3: Remove xconnect configuration before ISSU, and then add it back
after
 ISSU completes.
 
 
 

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.