listener timeout problem cannot figure out

This is very wierd to me but I don't know if it has something to do with Personal Edition of Oracle 8i, installed on Mandrake 2.4.8.

I started server by "lsnrctl start". then everything is ok. I tried jdbc thin connection from outside LAN, and it works fine. However, I must keep that jdbc program running. If i stopped that jdbc program for a little while, the network connection will fail.

java.sql.SQLException: Io exception: The Network Adapter could not establish the
 connection at
oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:168)

I checked the listener log, everything is OK, except that the client side get the above message. When I am trying jdbc connection from inside LAN, I never have that problem. I also check the sqlnet.ora file, set the timeout to a value =10, in case the firewall/gateway blocks traffice, but it doesn't work. I also tnspings it, works fine after that time-out. I did a netstat on it, doesn't see any packet loss. ....

does anybody know why? Received on Wed Feb 20 2002 - 12:09:29 CST