ora-12560 -tns protocol adapter error,is this a network or db error. occasionally I get this error,on restarting the service it again works.what might be the case .my db is oracle 8.1.5 on win nt -4.0.I reinstalled tcp/ip .still the same,is this network card prob or what?
this is network problem. So your db is not affected, but your listener is not working fine. Causes may be that a protocol es. TCP don't work fine. I had a similar problem (only the error) traced in my listerner.log and i went mad until i found the problem. My db was accessed in telnet on the port 1521, and tcp protocol in the listener didn't work for a while(telnet time)
This is taken from a UNIX utility that helps diagnose Oracle errors. May help:
12560, 00000, "TNS:protocol adapter error"
// *Cause: A generic protocol adapter error occurred.
// *Action: Check addresses used for proper protocol specification. Before
// reporting this error, look at the error stack and check for lower level
// transport errors.For further details, turn on tracing and reexecute the
// operation. Turn off tracing when the operation is complete.