NS3000/iX Operations and Maintenance Reference Manual (36922-90039)

76 Chapter5
Common Network Problems
Common Problems and Actions
is shut down. As a result, the processes that share a connection must
cooperate to ensure that no data is lost. Indications of a faulty
shutdown procedure on an individual or application level are:
• If you receive log messages or NetIPC error codes where the
recommended action for some of the log messages is to increase the
number of TCP connections, and the connections are not currently
active.
• If the TCP PM log message indicates that a packet was received
after the IPCSHUTDOWN call but before the TCP connection was fully
deleted.
Indication of a faulty shutdown procedure on a nodal level is an
incomplete shutdown of the network transport.
Network Transport Shutdown
Shutting down the network transport via the NETCONTROL STOP
command requires that all NetIPC call sockets, all TCP connections,
and all PXP sockets are closed. An error (Transport Shutting) is
returned to all open sockets. Until this error is received by the user and
the reply sent to TCP/PXP by NetIPC, the network transport does not
terminate. The Network Services shut down completely even if an
NSCONTROL ABORT has not been issued. However, it is important that
user applications always have a send or receive posted on any open
socket so that the shutdown error is delivered to them.
The only way to tell if the network transport has completely shut down
is to check the log file for the Control Process; Transport Stopped and
the TCP SIP/ General Protocol Stop nodal log messages. If these
messages have not been logged, the network transport is waiting for an
open socket and cannot completely terminate. The network transport
may be re-initialized even though the “old” transport has not
completely terminated. The two versions do not interfere with each
other, and the old one goes away when its last open socket is finally
closed. This old transport does not use any CPU and does not retain
“ownership” of the links, but the data structures that wait on the open
connection do use virtual memory.
If you find any of these indications, check any NetIPC applications for a
faulty shutdown procedure. Refer to the NetIPC 3000/XL
Programmer’s Reference Manual.