Preview Tool

Cisco Bug: CSCsz12394 - IOS crashes at be_netclk_create_source_on_standby after issu loadversion

Last Modified

Feb 06, 2017

Products (1)

  • Cisco ASR 1000 Series Aggregation Services Routers

Known Affected Releases


Description (partial)


With Network Clock configuration enabled, ISSU downgrade / upgrade (eg: Consolidated Package Upgrade) between RLS3 and RLS4 (and above) fail. On a 6RU, while the active RP remians functioning normally, the standby RP does not reach SSO. On a 4RU in DUAL IOS mode, the standby IOS instance does not reach SSO.


The following command shows the Network Clock configuration currently in use:
  <CmdBold>show network-clocks<CmdBold>

When functioning normally, the active RP output looks like so:
  router#show network-clocks 
  Active source = BITS T1 esf
  Active frequency offset = 0 ppm
  All Network Clock Configuration
  Priority    Clock Source    State    Reason
  1           BITS T1 esf     Valid    
  2           POS0/2/0        Valid    
  3           POS1/3/0        Valid    
  4           POS2/3/0        Valid    
  Current operating mode is Revertive 
  Current OOR Switchover mode is Switchover 
  There are no slots disabled from participating in network clocking

The following diagram illustrates the various possible downgrade / upgrade paths:

  RLS3.X <----------------> RLS5+
   ^                        ^   ^
   \                       /   /
    \            (5)      /   /
     \        +---------+    /
  (2) \      /              / (4)
       \    /              /
        v  v              v
      RLS4.0 <--------> RLS4.1+

The fix for this issue will be available in releases:
  RLS4.1+, and
The fix for this issue will __not__ be available in release:
The following releases are not altered in any way:

As a result, downgrade / upgrades paths (2), (3) and (5) will fail, as they all involve RLS4.0 (which does not have the fix).
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.