TECHNICAL INFORMATION DOCUMENT

TITLE:              PTF232 - RIP Packet Processing Changes
DOCUMENT ID:        TID300185
DOCUMENT REVISION:  A
DATE:               28FEB95
ALERT STATUS:       Yellow
INFORMATION TYPE:   Symptom Solution
README FOR:         PTF232

PRODUCT and VERSION:
UnixWare 1.1

ABSTRACT:

When a large number of network numbers (both internal and external) are
defined in the network, the amount of routing information received in
the per-minute RIP broadcasts from NetWare routers is correspondingly
large.  Processing this information sometimes results in noticeable
delays in the responsiveness of the UnixWare system; the problem is
particularly severe when the network cable segment on which the UnixWare
is located contains several routers.

SYMPTOM

System "hangs" or "freezes" for several seconds approximately once per
minute.

SOLUTION

Apply the ptf232 file.


Installation Instructions:

DATATYPE: datastream

1.  Download the ptf232.Z and ptf232.txt files to the /tmp directory   
    on your machine.

2.  Read the release notes contained in this file and follow the
    instuctions to add the packages to your system.

3.  Now become root, uncompress the file and add the package to your 
    system using the following commands:

        $ su
        # uncompress /tmp/ptf232.Z
        # pkgadd -d /tmp/ptf232 ptf232

Solution Specifics

When a large number of network numbers (both internal and external) are
defined in the network, the amount of routing information received in
the per-minute RIP broadcasts from NetWare routers is correspondingly
large.  Processing this information sometimes results in noticeable
delays in the responsiveness of the UnixWare system; the problem is
particularly severe when the network cable segment on which the UnixWare
is located contains several routers.

This patch installs a new IPX driver which changes the handling of RIP
broadcasts so that the impact on system responsiveness is significantly
reduced.  It also changes the default size of the IPX network "hash
table" to reduce the length of the "synonym chains" (network numbers
which hash to the same index number) IPX must search to locate a
specific network number.  Please see the comments in
/etc/conf/pack.d/ipxl/space.c for information on changing the size of
the hash table in the event that the default size is not satisfactory
for your network.


New Features.
------------

None

Software Notes and Recommendations.
----------------------------------

This PTF can be installed on any UnixWare 1.1.3 or 1.1.4 system which
has the NetWare Unix Client (nuc) package installed.  If this PTF is
first installed on a UnixWare 1.1.3 system and Update 1.1.4 is
subsequently installed, reinstallation of this PTF will be needed (it is
not necessary to remove it before reinstalling).

Testing of the modified software contained in this package has been
conducted only to the extent necessary to confirm that it resolves the
problem(s) stated above ("Symptom").  Such testing consists of
recreating the problem conditions and verifying that the problem no 
longer occurs.  No other testing of this software has been done.

Hardware Notes and Recommendations.
----------------------------------

This PTF is targeted for the i386, i486 and Pentium CPU's.

Installation Instructions.
-------------------------

This PTF consists of 1 3.5 inch floppy.  Insert the floppy into the drive
and, while logged in as root, type

     pkgadd -d diskette1

and follow the instructions output by pkgadd.

Troubleshooting.
---------------

The default network hash table size should yield satisfactory results
for most networks with up to (approximately) 4000 network numbers
defined.  For larger networks, it is still possible that a slight
"hesitation" may be observed at approximately one-second intervals for
several seconds after receiving a burst of RIP packets.  Depending on
the specific distribution of network numbers, this also possible for
smaller networks.  Below are some additional prime numbers that may be
tried for networks of various sizes.

     # of Network Numbers          Possible Hash Table Sizes
     --------------------          -------------------------
          4000                263, 269
          5000                331, 337
          6000                389, 397
          7000                457, 461
          8000                521, 523