Sustainable Sustworks - Tools for Internet Travel
Advanced Networking for Mactintosh Professionals


Testing Net Sentry

This page lets you to test operation of Net Sentry on your Macintosh.


You must have Net Sentry installed and running on your machine to perform all tests. (installing Net Sentry from the installer and restarting your Macintosh will automatically make Net Sentry run in the background with our default configuration).


You will be able to simulate an attempted intrusion into your Macintosh.

There are four different "attack" servers from which to test Net Sentry. Each test server has a unique IP addresses which is different than the IP address of our main site. Hence, even though these tests will trigger Net Sentry to install filters which will block further communication between your Macintosh and one or more of these test servers, these filters will not impare your ability to connect to our main web site (nor any other web site).

As you proceed from step to step, the results of your actions will be displayed in another browser window. Please return to this page to continue testing.

Step 1. Select a test server from which you will run the tests and trigger Net Sentry. Each test server can be considered a remote "intruder".

Test Server:

Step 2: Run a Ping test from this server by clicking the "Ping " button. This will demonstrate that the test server can indeed reach your machine (before triggering a Net Sentry filter). This test assumes that you HAVE NOT added the ICMP filter to your Net Sentry configuration file. IF you have added the ICMP filter to your Net Sentry configuration file, goto Step 3.

Step 3. Choose a Service OR enter a protocol and port to trigger Net Sentry. Typical services an intruder would look for running on your Macintosh include a SMTP (email) server (TCP Protocol - Port 25), a FTP server (TCP Protocol - Port 21) , a SNMP server (remote network management TCP Protocol - Port 161) , a Telnet server. (TCP Protocol - Port 23) or a DNS server (UDP Protocol - Port 53).

The default Net Sentry configuration installs triggers for :

  1. SMTP (TCP - 25)
  2. SNMP (TCP - 161)
  3. Telnet (TCP - 23)
  4. DNS (UDP - 53)
  5. FINGER (TCP - 79)
  6. POP3 (TCP - 110)
  7. SunRPC (TCP - 111)
  8. LPD (TCP - 515)
  9. SOCKS (TCP - 1080)

You should test with one of these services if you are using the default Net Sentry configuration file (as installed with our installer).

Select Service
Or Enter
(tcp or udp)
Port Number
(1 - 65535)

Step 4. After choosing a service or entering a Protocol and Port Number, click the "Attempt Intrusion" button.

If your Net Sentry configuration file was setup with notification type 1, 2 or 3, you should have been notified of the intrusion attempt (default notification is type 1, which is a simple alert).

Step 5. Run another Ping test from this server by clicking the "Ping" button.

This shows that the "Intruder" is now completely blocked from accessing your Macintosh, and cannot even Ping your machine (your machine is essentially invisible to this Intruder).

Repeat these steps using the other test servers. This will demonstrate the fact that Net Sentry only blocks remote machines immediately after an intrusion attempt (trigger is hit).