Symptom
ASR1006X SIP's timestamp is not synced after some time:
ASR1006X#show clock
00:20:01.580 UTC Tue Feb 20 2018
ASR1006X#
ASR1006X#request plat soft console attach 1/0
...
Slot-1-0#show clock
*15:08:14.548 UTC Fri Dec 15 2017
Further Problem Description
Technically speaking: the root cause for the issue is SNTP client process as in IOS-XE CC and FP clock is synced from RP through SNTP process. SNTP server instance is running on RP side (/usr/bin/sntp -S) and SNTP client instance is running in CC side and SNTP client get the clock update from server by polling every 6 mins. In a failed state, the SNTP process instance is not there in CC side and the process is just dead and is not auto re-spawning once it is dead. Since SNTP client process is not running, clock update is not happening.
Releases from 16.5.x and 16.6.x are not affected.
