Io Error: Got minus one from a read call
When trying to connect using oracle sqldeveloper this error messages is thrown. I came across this error two times, on each occasion different cause. 1) Make sure you are connecting to the correct port, wrong port also gives the error above. 2) This is happening becuase oracle is using ACL (access control list) where only authorised clients are given access. check sqlnet.ora file ($ORACLE_HOME/network/admin) tcp.validnode_checking = yes tcp.invited_nodes=(ORACLE11I.mylearn.com) we can either disable this checking tcp.validnode_checking = no or add the node in the acl. tcp.invited_nodes=(ORACLE11I.mylearn.com,192.168.1.14) bounce the listener and try connecting again if oracle apps is using use addlnctl script to bounce it. http://forums.oracle.com/forums/thread.jspa?threadID=431151