PHNE_43814 - 11.31 cumulative ARPA Transport patch

[Dave Cast]

All,

Reading the special instructions for the above it states:

Warnings:

 14/10/27 - This Critical Warning has been issued by HP.
 - PHNE_42470 introduced behavior that may result in data
 corruption when TCP SACK is used.
 - This behavior is also experienced with superseding patches
 PHNE_43412 and PHNE_43814.
 - HP does not recommend removing the patches. To avoid this
 behavior, HP recommends that TCP SACK be disabled using the
 following command:
 /usr/bin/ndd -set /dev/tcp tcp_sack_enable 0
 This will apply to new TCP connections.
 In order to have this change persist after a system reboot,
 the following entries must be added to
 /etc/rc.config.d/nddconf:
 TRANSPORT_NAME[x]=tcp
 NDD_NAME[x]=tcp_sack_enable
 NDD_VALUE[x]= 0
 where '[x]' must be set according to the other ndd parameters
 in the nddconf file.
 - Additional details on this behavior may be found in Change
 Request QXCR1001374339.

Is this anything to be actually concerned about?  I looked of TCP SACKS and it has to do with Selective ACKS (acknowledments) - am I to believe I need to make a network configuration change on all my production servers (ndd) to apply this patch?  Can anyone give me the 'skinny' on this?

Thanks in advance,

Dave

P.S. This thread has been moevd from General to HP-UX > networking. - Hp Forum Moderator

[Bill Hassell]

No patching is needed.

ndd parameter(s) can be changed while running by editing the file mentioned above, then running ndd -c to re-read the config file. Verify that the change was made by running : ndd -get /dev/tcp tcp_sack_enable

If you don't have anything in the current ndd config file for all your servers, you can add this parameter plus one more that has been mandatory since version 11.00 (ie, disable dead gateway detection). Here is an example for these two parameters:

TRANSPORT_NAME[0]=ip
NDD_NAME[0]=ip_ire_gw_probe
NDD_VALUE[0]=0

TRANSPORT_NAME[1]=tcp
NDD_NAME[1]=tcp_sack_enable
NDD_VALUE[1]= 0

Once the file is in place, run ndd -c then the ndd -get ... command to verify the new settings.

You can then copy this file to all of your servers (any version of HP-UX starting with 11.00).