Pass ctrl-q char to unlock it from telnet hung state #37
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eduran-cisco
approved these changes
Jul 9, 2024
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https://wwwin-github.cisco.com/cafy/cafykit/issues/29137 will track the removal of this after the XR issues are resolved
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There have been multiple runs that have failed in the cleanup stage while connecting to the console via telnet.
The connection to the device is tried for ~15 minutes by sending newline character periodically to see if any prompt is received. However, it is observed that no prompt is received and eventually the job fails.
this is been confirmed manually as well.
RC: It seems like the in the previous session, the device was exited after doing ctrl-s. A specific set of sequences (ctrl+s) sent can cause the console to go into flow control enable mode.
By sending out the sequence (ctrl+q) we can disable the flow control.
Already DDTS are in placed CSCwh67759 or CSCvy64395
How the device landed in flow control enabled state (by sending ctrl-s) is unknown because health check successfully runs on a testbed , brings it online and then is dispatched for a run. Possibilities of human intervention without reserving a testbed. In order to determine this, Eduardo is being notified to create a sytem that can log every telnet login to a device.
Logs of issue in cleanup stage :
jenkins_log
netmiko_log
Logs after sending ctrl-q:
here