telnet : could not open connection to host - oracle

Question

I am trying to remotely access oracle DB using jdbc but got problems, after searching through i learned that ports might be blocked by the firewall.
I am getting the following error when i am executing the command to test if port is opened or not,
telnet MyIP 1521
Connecting to MyIP...Could not open connection to the host, on port 1521 : Connect failed
I tried opening the ports by making new inbound rule but still the error exists.
Atlast i turned my firewall off but it's still the same.
If i try the same command for localhost, i.e.,
telnet localhost 1521
It works, but using my ip address it's not.
How can i resolve this ?

Answer 1

Some ISP's block certain ports that might be targets for certain attacks. I know with MSSQL it uses port 1433 or something similar, and my service provider blocks connections to that port.
Try setting up your dB to use a different port than the standard and see if that works. You could also call your provider to see if they're actually blocking the port.

Answer 2

Configuring the connection between client and server Oracle 10g
In a comment you have an extract from lsnrctl status:
Listening Endpoints summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0.1)(PORT=1521)))
Services summary...
Your listener is only listening on 127.0.0.1, so connections can only be made from the server. There is nothing listening on your external address 10.0.2.39, so connections to port 1521 on that address fail.
Your listener.ora presumably has something either a single ADDRESS, or no ADDRESS at all, which will default to localhost:1521. You need to modify it to something like:
LISTENER =
...
(ADDRESS_LIST =
...
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = 10.0.2.39)(PORT = 1521))
)
or your machine's host name if that's resolvable to that address. Ideally this would be done through netca rather than by editing the file by hand.