APAR PN90532 -

   IP PACKET TRACE CAUSES HANG IN OS/2 TCP/IP.


To apply this fix, unzip the self extracting executable:          
                                                                  
     PN90532 .
                                                                  
Note that the '.' is important because it will unzip into the     
current path.                                                     
                                                                  

Files included with this APAR:                                    

  9-09-96  11:54a     14095           0  ifconfig.exe
11-15-96  11:55a     32653           0  so32dll.dll
11-15-96  11:55a     89825           0  tcp32dll.dll
11-15-96  11:55a     44895           0  tcpipdll.dll
11-22-96  11:09a     32431           0  ifndis.sys
11-22-96  11:09a    129404           0  inet.sys
 2-28-97   9:55a      3549           0  read.me
 2-28-97  11:12a      2625           0  install.doc


Installation
------------
Download PN90532.EXE as binary, and execute as directed above.
Copy the following files to your IBMCOM\PROTOCOL subdirectory:
    INET.SYS, IFNDIS.SYS
Copy the following files to your TCPIP\BIN subdirectory:
    INET.SYS, IFNDIS.SYS, IFCONFIG.EXE
Copy the following files to your TCPIP\DLL subdirectory:
    TCP32DLL.DLL, TCPIPDLL.DLL, SO32DLL.DLL
Then reboot your system, and the new stack fixes will be loaded.
  To verify the proper level of the stack is loaded, type INETVER from
  an OS/2 command promp and the returned value should be:

            Inet Version: 2.07L

  (see INSTALL.DOC for additional installation information)



*************************************************************************

The following readme file (PN68589.README) was generated for a previous
apar on the TCP/IP Version 2 for OS/2 product stack.  The entire content
of that readme is also applicable to customers applying apar  PN90532.
====================================================================
PN68589.README:


This file describes a fix to IBM TCP/IP version 2 for OS/2.  The APAR
number for this fix is PN68589.  These files should be installed on
top of IBM TCP/IP version 2 for OS/2 after the latest CSD.  You should
be at CSD level 64092, which you can check with the syslevel command.

Who Needs This Fix?
-------------------

These files permit you to customize the TCP send buffer size,
receive buffer size, and segment size.  By default, OS/2 TCP/IP uses
a send and receive buffer size of 28k, and a segment size of 1460.
These are usually very good values, except in the following cases:

(a) You may have a network card with very little onboard memory,
such as the 3COM 3C509.  The TCP/IP stack must be tuned down to
work well with such cards, because it is very easy to overrun the
memory buffers when running TCP/IP full blast, and this causes
packet retransmission and performance problems.

(b) You may be using an application such as the Sybase Replication
Server that keeps many sockets open simultaneously.  The TCP/IP
stack does not reserve enough memory to allocate 28k of send and
receive buffers for all of the sockets in the system.

In either case, you can tune TCP/IP to work well with the following
command:

ifconfig lan0 sendbuf 4096 recvbuf 4096 segsize 1024

You may want to create a tcpexit.cmd file in your tcpip\bin subdirectory
with this command in it.  Tcpexit.cmd is run after TCP/IP starts.

By default, the TCP segment size used by OS/2 TCP/IP over routed
connections is 576.  If your routers support larger frame sizes (for
example if your routers connect separate Ethernet segments, you may
want to use a larger value.  Use this command:

ifconfig lan0 -use576    [This TOGGLES OFF the 576 segment size]

and a TCP/IP segment size of 1460 will be used over routed connections.