The Database as a Networked Server - Implementing Database Security and Auditing - page 81

3.5 Use port scanners—so will the hackers

Shutting down unnecessary communication protocols is a great thing. The
next step is to shut down unnecessary networked services and ports. Any
database will open and maintain numerous ports on the network, and you
should be aware of these. Many people think they understand which ser-
vices are up and listening on the network, but some only know the half of
it; make an effort to track and monitor open ports and services. As an
example, most SQL Server database administrators (DBAs) know that 1433
is a port that SQL Server listens to, but previous to SQL Slammer many
were not aware that UDP port 1434 is also active. As another example,
Table 3.1 lists the default ports for various Oracle network services that may
be active. How many of you Oracle DBAs actually think about all of these?

Table 3.1 Oracle Listener Ports

Port Number Description

1521

Default port for the TNS listener

1522-1540

Commonly used ports for the TNS listener

1575

Default port for the Oracle Names Server

1630

Default port for the Oracle Connection Manager-client connec-
tions

1830

Default port for the Oracle Connection Manager-administrative
connections

2481

Default port for Oracle JServer/JVM listener

2482

Default port for Oracle JServer/JVM listener using SSL

2483

New officially registered port for the TNS listener

2484

New officially registered port for the TNS listener using SSL

Another example (from a somewhat different environment) is Table 3.2,
which lists the default ports in an Oracle 11i environment (including an
Oracle database).
There are two tools you should know about. The first—called netstat —
allows you to display current TCP/IP connections. Netstat runs on all oper-
ating systems. For example, if I run netstat on my Windows machine (which