I have Windows Server 2008 R2 with Oracle Client 126.96.36.199.0 client installed. TNSPing to 100% available databases (accessible from other machines, i.e. I can do TNS ping to these databases from other machines) returns me following error: TNS-12535: TNS:operation timeout. At the same time I can telnet to database host/port and see that proper tnsnames file is being used. Environment variables are configured as appropriate (ORACLE_HOME, TNS_ADMIN, Path). Also I can connect via telnet using service/host name + port - so this is unlikely a firewall issue.
After enabling Oracle client logging I can see following error related details in tnsping.trc:
snlinGetAddrInfo: getaddrinfo() failed with error 11001
The only strange/suspicious thing about this machine is that it had multiple versions of oracle client installed (10, 11.1, 11.2) - removal of all versions apart from 11.1 & reinstall/repair of 11.1 haven't resolved this issue. Also it seems to me that v10 of client was not removed properly - it disappeared from Programs and Features, but files in installation folder had not been deleted.
Any advice on what to check / how to resolve this issue?