All I am having a problem as follows. The database server is Windows NT4 SP6. Database version (pathes 1 - 5). The machine resides between two firewalls. I can connect to the machine using SQL plus from a the local machine, or from a machine in the same segment of the network (between the two firewalls). Howerver when I try an connect from a machine that is outside this segment I get an ORA-12203 message. I can view the firewall logs and I call back seems to be generating random ports. The listener is listening on port 1526.