Preview Tool

Cisco Bug: CSCta18596 - Tracebacks and interface instability while FR fragmentation configured

Last Modified

Jan 31, 2017

Products (1)

  • Cisco IOS

Known Affected Releases


Description (partial)

Symptoms: The following tracebacks and messages appear on the console logs:
 %ALIGN-3-SPURIOUS: Spurious memory access made at 0x61AB0C78 reading 0x22
 %ALIGN-3-TRACE: -Traceback= 61AB0C78 623849E8 62384A58
  607CCD8C 61372428 613769FC 61376E68 613773C4
 In addition, you may see instability of the serial interfaces (i.e.: when an
 interface is configured, it stays up for a while and then goes down).
 Conditions: The symptoms are observed when upgrading to Cisco IOS Release
 12.2(31)SB14 on a Cisco 7200 series router only on the interfaces configured
 with frame-relay fragmentation configured on the main interface.
 Workaround 1: Use fragmentation in the map-class with FRTS (i.e.: configure
 "frame-relay traffic-shaping" under the main interface and configure
 fragmentation under the map-class and apply the map-class to PVC). For 
 interface Serial1/0.1/1/4/2:0
  no ip address
  encapsulation frame-relay IETF
  frame-relay traffic-shaping
  frame-relay lmi-type ansi
  frame-relay intf-type dce
  no clns route-cache
  max-reserved-bandwidth 100
 interface Serial1/0.1/1/4/2:0.101 point-to-point
  frame-relay interface-dlci 101   
   class BANKOFIRE-S1/0.1/1/4/2:0.101-SR611638725
 map-class frame-relay BANKOFIRE-S1/0.1/1/4/2:0.101-SR611638725
  frame-relay cir 768000
  frame-relay mincir 768000
  no frame-relay adaptive-shaping
  service-policy input BANKOFIRE-IN-S1/0.1/1/4/2:0
  service-policy output BANKOFIRE-OUT-S1/0.1/1/4/2:0
  frame-relay fragment 600
 Workaround 2: Make sure that the fragmentation size is different in different 
 interfaces (with interface fragmentation).

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.