Hi, I've had this issue before and indeed, it was a network issue. No firewall/port issues though, just the network being pretty much collapsed because of an extremely high traffic. Regards, David On 23 February 2011 14:24, KRISHNA MOORTHY <krish33moorthy@xxxxxxxxx> wrote: > Hi > > We are getting frequently the following error in alert log files of > production server.It was running fine for last 3 months.There is no > changes in listener configuration. > > WARNING: inbound connection timed out (ORA-3136) > > In Sqlnet.log file the following error is getting displayed. > > TNS-12535: TNS:operation timed out > nt main err code: 0 > nt secondary err code: 0 > nt secondary err code: 0 > nt OS err code: 0 > nt OS err code: 0 > ns secondary err code: 12606 > nt main err code: 0 > nt secondary err code: 0 > nt OS err code: 0 > TNS-12535: TNS:operation timed out > ns secondary err code: 12606 > nt main err code: 0 > nt secondary err code: 0 > nt OS err code: 0 > TNS-12535: TNS:operation timed out > ns secondary err code: 12606 > nt main err code: 0 > nt secondary err code: 0 > nt OS err code: 0 > > When i searched on the net,they are telling that it might be an network > issue.But when i asked the network team , they said there is no firewall > /port block issues.Please help me to resolve the issues. > > Regards > Krishna > 9585354917 > -- > //www.freelists.org/webpage/oracle-l > > >