Some previous post related to issues in Networking on AIX 4.3
and Netcards config.

Other changes that should be noted about the difference
 between AIX 4.2 networking and 4.3.

 1) DNS Default is looking for a IPV6 DNS Server.
 2) PMTU Discovery can clone virtual nets

Along with configuring network cards to a specific
setting, AIX may require being configured IPV4.

Here are some of the things that can be changed to
configure AIX 4.3 networking to IPV4 type.


/etc/netsvc.conf
hosts=local,bind4

/etc/rc.net
if [ -f /usr/sbin/no ] ; then
        /usr/sbin/no -o tcp_pmtu_discover=0 >>/dev/null 2>&1
        /usr/sbin/no -o udp_pmtu_discover=0 >>/dev/null 2>&1
        /usr/sbin/no -o ipforwarding=0 >>/dev/null 2>&1
fi



Also with the SP/2 and a switch, ADSM (3.1) docs gave
some real differences in network settings from what
by lots of testing came to be the optimum solution for
our environment.
(We still have plenty of 10Mb ethernet in the mix)
After ariving with these figures most of the connection related
'readRtn' etc.. went away.

/etc/rc.net
if [ -f /usr/sbin/no ] ; then
        /usr/sbin/no -o thewall=65536         /usr/sbin/no -o
sb_max=163840         /usr/sbin/no -o tcp_sendspace=65536
/usr/sbin/no -o tcp_recvspace=65536         /usr/sbin/no -o
udp_sendspace=32768         /usr/sbin/no -o udp_recvspace=65536
/usr/sbin/no -o tcp_mssdflt=1448 fi


Sincerely,
Bart

"All information is in my opinion soley"