Connection Problem Oracle 8.1.7 on Win2000

Question

Hi,
I have installed Oracle(8.1.7) on Win2000 Server and I installed Dev2.1 on client and when I am connecting to this database I am getting the foll error
ERROR:ORA-12545:TNS:name lookup failure
I checked the TNSNAMES.ORA file on Client and specify the IP address of Server but still it is not connecting but when I am giving TNSPING <service name> It shows me ok it means it listening to server.
Can anyone Please help me in this

Answer 1

The ORA-12545 error is a failure to resolve a hostname to an IP address, which
usually means that the hostname in the (host= <hostname>) value in the
tnsnames.ora is not resolving.
Occasionally clients will get this error even though they already have the IP
address in the tnsnames.ora. The reason for this is that when a client makes
a connection to a listener on Windows NT or a shared connection to a listener
on Unix, the connection gets redirected. What this means is that a redirect
packet is sent back from the listener to the client and the client then makes a
new connection. When the listener redirects the connection it sends the
addressing information from the listener.ora, or in the case of MTS the
init.ora, back to the client in a redirect packet. The client must then
resolve that addressing information. If the listener.ora or init.ora
contains a hostname that the client can't resolve, the connection attempt will
fail with an ORA-12545 error even though the information in the tnsnames.ora
is correct.
This error can often be resolved by using the server's ip address instead of
hostname in the listener.ora (init.ora if using MTS) which should force the
listener to use the ip address in the redirect packet. A better solution to
this error is to enable the client to resolve the hostname that is being
returned in the redirect packet.
When the client machine is capable of resolving the fully qualified domain name
to an IP address this error will not occur. This is done by adding the server's
IP address, hostname, and fully qualified domain name to the name resolution
method the that network is using (usually DNS). If this is not possible,
the information can be added to the client machine's hosts file.
On NT this file is located at c:\winnt\system32\drivers\etc\hosts
Because redirects in 8i contain the fully qualified domain name, hostname to
IP address resolution is critical for a successful connection.