Oracle Database Discussions

Hi,

I have another strange problem. I have two computers A and B. Both have an Oracle database server instance. I manage the one in B (which is my local computer) but not the one in A (which is a computer where I have a user account and an Oracle account but I don't own or manage).

I tried to establish a database link on the database in B pointing to the one in A. This works.

When I try the opposite, that is, establish a database link on the database in A pointing to the one in B I cannot get it work. I can create the database link but then when I try to use it (e.g., by submitting a "SELECT") it blocks for a long time and finally returns "ORA-12535: TNS:operation timed out". I tried to execute telnet from A to B using the port of the Oracle database server in B and it seems that the connection is established. I tried something similar with tnsping but this does not work, as I get again the timeout. I tried deactivating the firewall on my computer B, but it does not work either (besides, the telnet passes through even if I have the firewall activated).

Any idea?

My TNSPING looks like this:

tnsping '(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = <the-target-ip>)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = XE)
)
)';

I also tried with:

tnsping '(ADDRESS = (PROTOCOL = TCP)(HOST = <the-target-ip>)(PORT = 1521))';

I'm lost... Any ideas are very much appreciated.

Thanks!