I am running CENTOS 5. I have an application on the linux computer that needs to connect to an Oracle 10g database on a Windows XP pc. The Oracle database is set-up as a "share" on the pc. I can ping the windows pc from my linux pc.
Any suggestions?

Thanks,
Ed

Determine which port the Oracle DB is "listening" on (default is 1521).

Try to attach to the specific port with the telnet command:

e.g.
telnet <windows host that has oracle> 1521

If you see it connect it means you can get to it from the Linux host.

If you don't see it connect it could mean:
1) The DB isn't listening on the port you tried.
2) You have Oracle security configured to only accept the hosts/IPs you've defined and you'll need to modify that. (Not a DBA so can't help you there.)
3) There is something blocking the connection (e.g. Windows firewall, Linux iptables or a firewall device between the Windows host and the Linux host.) Typically it wouldn't be iptables as most people only prevent INBOUND to the Linux host and allow all outbound (i.e. your connection to the Windows host).