TNS-12535 / ORA-12535 on Connection to Database (Doc ID 214122.1)

Last updated on AUGUST 15, 2016

Applies to:

Oracle Net Services - Version 8.1.7.0 to 12.1.0.2 [Release 8.1.7 to 12.1]
Information in this document applies to any platform.
***Checked for relevance on 15-AUG-2016***

Symptoms

Oracle Net connections to database fail with error code TNS-12535 / ORA-12535: TNS:operation timed out.
Oracle Net client trace can show large delay upon resolving TNS listener host

[03-AUG-2005 09:42:29:385] nttgetport: port resolved to 1521
[03-AUG-2005 09:42:29:385] nttgetport: exit
[03-AUG-2005 09:42:29:385] nttbnd2addr: looking up IP addr for host:  
sample.com
[03-AUG-2005 09:46:12:658] nserror: nsres: id=0, op=65, ns=12535, ns2=12560;
 nt[0]=505, nt[1]=145, nt[2]=0; ora[0]=0, ora[1]=0, ora[2]=0
[03-AUG-2005 09:46:12:658] nsopen: unable to open transport

Sample trace from Solaris and shows lowest error code in the stack is nt[1]=145

nserror: nsres: id=0, op=65, ns=12535, ns2=12560; 
 nt[0]=505, nt[1]=145, nt[2]=0; ora[0]=0, ora[1]=0, ora[2]=0 

Errno.h

#define ETIMEDOUT 145 /* Connection timed out */


Sqlnet.log will also show the error stack

Cause

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