Problem in runing listener with logical ip

[gautamsinha01]

Hi,
There are two servers, say a1 and b1.And server is in cluster.
In a1 server-db1 is active and db2 is standby and in b1 server,db2 is active and db1 is standby.
The problem is in running the listener.
When we start the listener using physical ip its started but when we try to run the listener using logical ip its not started. When we see in to the listener.log file, it shows that the error like 'TNS-12514: TNS:listener could not resolve SERVICE_NAME given in connect descriptor
30-SEP-2007 01:09:27 * (CONNECT_DATA=(SERVICE_NAME=ORADB)(CID=(PROGRAM=sqlldr@sandb2a)(HOST=oradb2a)(USER=oracle))) * (ADDRESS=(PROTOCOL=tcp)(HOST=192.168.106.4)(PORT=42308)) * establish * SANDB2 * 12514
TNS-12514: TNS:listener could not resolve SERVICE_NAME given in connect descriptor'
What could be the problem.
We are able to telnet through logical ip.
Please help..

[davey23uk]

the listener is running fine, it just doesnt now about the database you are connecting to