Advanced Network Testing

From FreekiWiki
Jump to navigation Jump to search

This page has been migrated to a document on Free Geek's Google Drive.

Information remaining behind may no longer be relevant.


When you have tagged this page as migrated,
please add a link to the new document on Google Drive.

(Link to new page immediately below.)


Commercial Grade Network Device Testing

This section is a generic guide for testing commercial grade routers, switches, firewalls, etc. If you are trying configure a small consumer grade switch, refer to the Basic Network Test Page.

Testing a network device with a console port

Most commercial grade routers, switches and firewalls have a console port that is used to configure the device (if it does not, the standard Network Testing page will have better instructions). The industry standard for console ports is to operate at 9600 bps, 8 data bits, no parity and 1 stop bit but, if you are having a difficult time communicating with a device, you should also try 19200, 38400 and 115200 bps speeds. It is unlikely that you will need to change the other communications parameters.

Step 1a: Return the device to factory defaults. There is typically done by pressing a "Reset" button, but techniques vary between manufacturers and models. For example, the Juniper Networks NetScreen-5GT Firewall requires you to wait for the unit to completely boot up, then press the reset button for six seconds, release the button for two seconds, then press the button for another six seconds. If you are having a difficult time defaulting a device, do a Google search that includes that manufacturer and model and the words "factory default". Reset buttons are usually recessed and require you to insert the end of a paper clip into a hole in the case of the unit that has the reset button behind it.

Step 1b: If the device does not have a reset button or the reset button doesn't seem to work, try the second method. The second way of resetting a switch is to access its console. Learning how to do this early in the testing process generally helps. The easiest application to use for communicating with console ports is GtkTerm (Applications -> Accessories -> Serial port terminal). The lower left corner of the GtkTerm window displays the serial port device name, the port speed, number of data bits, parity type, and stop bits. This should usually read like this: /dev/ttyS0:9600,8,N,1. Launch GtKterm, connect the serial cable between the Network Test Station PC and the device under test, then power up the device under test and watch the screen. You may need to experiment with different speeds listed above (Configuration -> Port). Getting console port access does not guarantee that you will be able to default the device. If it is password protected, Google is you friend!

General Instructions and Caveats for Firewalls and Broadband Routers

  • After being defaulted, most firewalls and broadband routers will act as a DHCP server on all ports except for the "WAN" or "Internet" port. NEVER connect a device that is acting as a DHCP server to the Free Geek network.
  • Instead, use the DHCP server box in the middle of the Network Test Station and plug that a cable from it into the "WAN" or "Internet" port on the device.
  • Most firewalls and broadband routers have a web server built in to them to access status and configuration screens. Accessing these screens is proof that the port the Test PC is currently plugged into is working. These screens are typically accessed by entering into the address bar in the web browser you are using (probably Mozilla Firefox).
  • If the device's web interface can't be accessed at address, open a Terminal windows (Applications -> Accessories -> Terminal) and enter ifconfig to view the configuration of the ethernet interface on the PC. Find the IP address of the interface and try surfing to that address, but with the last octet changed to a 1. For example, if ifconfig reports an address of, try surfing to
  • If the device you are testing has WiFi capability, connect to it via the WiFi interface in the Network Test Station PC or via the test Laptop.

Test Procedures for Specific Models

Cisco PIX Firewalls

Cisco Routers

Juniper NetScreen-5GT Firewalls