I agree on the RAC point--it should be the VIP name/address in a RAC cluster. I also agree that in most cases for single-instance database servers you can safely leave it unset. However, I think setting it to HOST=localhost may only allow connections from the database server itself since it would cause the listener to listen on 127.0.0.1 and *not* on other IP addresses (like the "real" IP address of the host). I can't easily test this right now, but I'm pretty sure it's correct for current versions. It will also and almost always be affected by whether or not you specify (IP=FIRST) in the ADDRESS section as well. Have a look at ML 421305.1 for some really good and relevant information related to your question. It is also valid syntax to use (HOST=) and that will also cause the listener to invoke default behavior and listen on the IP address that corresponds to the hostname of the server it is running on (or possibly on 0.0.0.0, which is synonymous with all IP addresses on the node). Dan On Fri, Dec 5, 2008 at 8:40 PM, Bobak, Mark <Mark.Bobak@xxxxxxxxxxxx> wrote: > Hi Maureen, > > One reason I can think of to not use the definition you've specified, is > RAC. In the RAC environment, you'll want to specify a VIP address for the > local listener. Other than that, if you're not on RAC, leave local_listener > unset, and it will default to port 1521 on the localhost. > > Hope that helps, > > -Mark > ________________________________________ > From: oracle-l-bounce@xxxxxxxxxxxxx [oracle-l-bounce@xxxxxxxxxxxxx] On > Behalf Of Maureen English [sxmte@xxxxxxxxxxxxxxxx] > Sent: Saturday, December 06, 2008 1:16 AM > To: oracle-l@xxxxxxxxxxxxx > Subject: Simple listener parameter question > > Hi, > > For those of you who have a LISTENER running on the same machine > as your database(s), do you configure the local_listener parameter > to have the actual host name, or localhost? Does anyone know of > any reason not to use something like > > local_listener='(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1234))' > >