How to Use the NetGuardian to Monitor Its Own LAN Connection

One of the great things about the NetGuardian is that it's a LAN-based remote that's still operational when the LAN is down. Because of its internal modem and paging capability, the NetGuardian always has an alternate path for sending alarm data, even if your entire LAN fails.

This means that the NetGuardian can effectively monitor its own LAN connection. Many users have configured their NetGuardians to send a pager notification if the LAN connection fails. (Pager notifications can also be used to provide continued visibility of other critical alarms during a LAN failure.)

Network Architecture Prevented the NetGuardian from Detecting LAN Failures

But we recently received a call from a client who wasn't getting notification of LAN failures, because his network architecture didn't give his NetGuardian a direct connection to the LAN.

Instead, the NetGuardian was connected to a hub which was connected to a CISCO router. The router would lose its link to the LAN, but the NetGuardian would not detect this. Since the link between the NetGuardian and the hub was OK, the NetGuardian detected a working LAN connection.

Getting Visibility of LAN Failures Was Essential to the Client

This was a serious problem. The client also had revenue-generating equipment connected to the router, and if he had no visibility of the condition of the LAN, he also had no way of knowing his essential equipment was offline.

Furthermore, because the NetGuardian detected a working LAN connection, none of the alarms it was monitoring were reported on its alternate dial-up path. Critical equipment failures and environmental alarms could pile up without the client having any visibility of them.

The Solution

DPS Telecom support technician Chris Hower took the client's call and devised a solution. Chris showed the client how to configure his NetGuardian to determine the state of the LAN by pinging a workstation on the far side of the router. If the ping fails, the NetGuardian will send an alphanumeric page to a technician.

Improved NetGuardian network architecture. Now the NetGuardian pings a workstation beyond the local router to test the LAN connection.

This configuration gave the client visibility of the LAN beyond the NetGuardian's local connection.

How to Do It Yourself

If you would like to create a similar configuration for a NetGuardian on your network, here's how you can do it:

1. First, you'll need to collect some information about your network. You'll need to know:
   
   • IP Address of the NetGuardian
   • IP Address of workstation beyond router
   • Pager and pin number of alphanumeric pager
2. Connect to the NetGuardian and log in. (All examples shown are taken from the NetGuardian web browser interface, but the same tasks can be accomplished through the TTY interface.
3. To set up the pager notification, click Edit.
   
   
   
   
4. Click on the Edit Pager link.
   
   
   
   
5. Select the notification method in the drop-down menu. In this example, we'll select an alphanumeric pager.
   
   
   
   
6. Fill in the pager number and pin. (Note: Most TAP terminals will use the serial format 1200 baud 7,O,1. If this does not work for you, contact your paging company for the correct speed and word format). Click the Submit Data button.
7. To define the ping target, click Edit Ping Targets.
   
   
   
   
8. Enter a description that will let the person being notified know what the problem is. Be descriptive as you have 48 characters available.
   
   
   
   
9. Fill in the IP address of the far end device. Leading zeros are not necessary. Enter the number of the notification device you defined in step 6. Click the Submit Data button.
10. To configure the ping settings, click Edit Timers.
    
    
    
    
11. The cycle timer defines how often the NetGuardian cycles through your ping targets. The wait timer defines how long the NetGuardian waits for a response. The fail timer defines how long the ping target is in a failed condition before an alarm is reported. Once you have decided on timer values, click the Submit Data button.
    
    
    
    

Configuration is complete. Now your NetGuardian is set to ping beyond the router.