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Cisco Bug: CSCtc23794 - WCM ping loss: DSID seq-num not cleared in SPA for DSIDs in higher range

Last Modified

Feb 05, 2017

Products (1)

  • Cisco uBR10000 Series Universal Broadband Routers

Known Affected Releases


Description (partial)

 - Some wideband cable modems are w-online but cannot be pinged.
 - DOCSIS pings to CMs can be done successfully.
 - This results in loss of IP connectivity for the modems.
Note that the symptoms mentioned above are quite generic. This ddts is used to 
track the issue that is observed in 12.2(33)SCB4 that is a side-effect of the 
CSCta71839 fix.

When the CMTS has been running for a few days, a CM that comes online is 
assigned a previously used DSID that has some residual seq-num in the SRAM. 
This results in using a non-zero value as a packet sequence number in the DS 
EHDR of the first packet. Some CMs do not accept non-zero seq num in first 
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Bug Details Include

  • Full Description (including symptoms, conditions and workarounds)
  • Status
  • Severity
  • Known Fixed Releases
  • Related Community Discussions
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