Just to notify the list of Bug 16268804 : GI STACK NOT STARTING ON POST APPLY OF 11.2.0.3.5 PSU that has been biting me for more than a day now. CSSD will not start on the second node (depending on the order how you start OHASD in the cluster) and ocssd.log will show “gipchaLowerRecv: invalid message header hdr” with broken multicast headers. It’s a little bit strange, because it could use broadcast as well (since 11.2.0.3), but I don’t know the background yet. I can confirm it on AIX 6.1 as well, so be careful. http://www.usn-it.de/index.php/2013/02/08/oracle-grid-infrastructure-11-2-0-3-5-psu-on-aix-gipchalowerrecv-invalid-message-header-hdr/ -- Usn's IT Blog for Linux, Oracle, Asterisk http://www.usn-it.de -- //www.freelists.org/webpage/oracle-l