Troubleshooting
Problem
The time stamp in the NETSTAT header is correct. But, the times in the output of the NETSTAT commands are in the future when a system is configured to use leap seconds.
Symptom
An example of this is the output from NETSTAT ALL:
MVS TCP/IP NETSTAT CS V1R9 TCPIP Name: TCPIP 20:20:03
Client Name: FTPUSER Client Id: 000A317E
Last Touched: 20:20:24
SendDataQueued: 0000283224
OldQDate: 10/29/2008 OldQTime: 20:20:24
Note how the header has a timestamp of 20:20:03 and the other fields are in the future with a timestamp of 20:20:24.
Cause
TCPIP obtains the time by using a STCK instruction. These time stamps are used internally in the TPCIP stack. These times do not take leap seconds into account. Time stamps used in other applications (including the NETSTAT header) are obtained in a different manner that subtracts leap seconds. When the two time stamps are displayed together in the same display (such as in NETSTAT), the time stamps used by TCPIP may appear to be in the future.
Environment
z/OS system using Sysplex Timer may be configured to use leap seconds.
Resolving The Problem
1. Problem does not occur on systems that do not specify leap seconds.
2. If you need to correlate the times, subtract leap seconds from the time stamps that appear to be in the future. The CVT field CVTLSO contains the value for leap seconds.
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Document Information
Modified date:
15 June 2018
UID
swg21326549