Oracle networking – some ugly duckings
I tried to answer a question in the forum a couple weeks ago about connections. It contained all the trite stuff about check this, then that, et cetera because I couldn’t remember why I’d seen an TNS-03505 error. It returns an illustrative message “Failed to resolve name” error. Along the way, I tripped into ORA-12560 and one I’d never seen before an ORA-12518. If you want the dirt on these read on …
You’ll typically encounter this error when you’re working on a laptop. It gets triggered when you run the
tnsping utility. When you’ve qualified the hostname and
hostname.domain name in the hosts file and in the
tnsnames.ora file, it’ll throw the
TNS-03505 error because you’re on another network. You may also encounter it when there’s a change or discrepancy between the machine hostname and DNS server results. Lastly, you may encounter it when you’ve lost the lease on an IP address and now have a new lease with a different IP address.
These errors effectively block successful
tnsping calls. You get around it by shutting down the listener, modifying the IP address in the
tnsnames.ora file if you’re not using a hostname, setting the
%TNS_ADMIN% environment variable in a command session when you have multiple Oracle homes, and restarting the listener.
This is the sqlplus utility cousin of the
TNS-03505. All the rules that apply to it apply to this.
This one is cute. I only hit it because my touchpad is too sensitive on the Dell laptop. It occurs if you pause the Windows listener service. You fix it by restarting the service. It is an enigma within a conundrum (Churchill on the old Soviet Union) why anybody would create a service like this with a pause option. Wouldn’t it be cool if somebody at Oracle were listening now (that is reading this blog) and they got the service fixed.