Not long ago, babysitting a computer network after-hours seemed unreasonable. No one needed network access after the office was closed, and little was being done other than network backups. Today, however, it is increasingly important to have 110 percent availability of all systems 24/7, from the mail server to the financial package.

There are value-added services that can assist you in managing uptime on all your servers, and it’s likely that your ISP has something that would allow your network to be watched by its network operations center, even though these services may add to the monthly cost of service. A small software company called RGE, Inc. may help you to bring the server monitoring capabilities with its program called IP Sentry. IP Sentry is a very inexpensive alternative to the monthly costs for some of the same services provided by your Internet service provider. IP Sentry will easily allow you to know if anything (at least in the way of PCs, X10 devices, and services) is out of whack on your network. Here’s what you’ll find in IP Sentry.

What is IP Sentry, and why should I use it?
IP Sentry is a monitoring tool that will watch your networked PCs and other connected devices and alert the necessary individuals if there is a problem. For example, I use IP Sentry to watch the connectivity of all the servers in my networked environment as well as to watch the Microsoft Exchange Information Store. This will alert me if any of these computers or services fail to respond to an ICMP Ping. This alone can decrease the cost of monthly payments to your ISP and is something to consider.

To get started, visit the IPSentry Web site and download the trial version of the software. During installation, the default settings will work for most instances. The software installs just like most normal Windows programs. When the software is installed, you will be able to use it for 30 days without the need to register.

You can complete the purchase form on the Web site to license the product for commercial use. IPSentry is licensed by site and by installation. For example, you can use one license for all the servers on your network as long as you install the software on only one PC, which will cost you about $100. If you need to install IP Sentry on more than one PC at your site, you will need a site license, which allows you to load the software on several PCs within one physical location, for about $400. If you need to install the software in multiple locations around the world, you will need an enterprise license, for about $2,000.

If you only need one administrator to handle IP Sentry, the single license will do the trick. One server running IP Sentry can monitor up to 32,000 devices. If you have more devices than that or have several closed networks within your corporate environment, a site or enterprise license will be a better fit for your network because it allows multiple installations.

Configuring the monitor of all monitors
All legal issues and licensing aside, let’s get into just how IP Sentry can help you monitor your network. To best illustrate the ease of use brought to you by IP Sentry, suppose the following is true: Your corporate network has a mail server, a Web server, and a file server.

In the above scenario, there are three PCs on the network, each of which has several services that allow it to run. Any Windows NT services can be monitored along with PCs to ensure that someone on your staff is aware that there is trouble on the network.

This, to me, seems like the best reason to use IP Sentry. Even a value-added ISP service that monitors servers for uptime cannot monitor the services and applications running on your network.

Since IP Sentry’s configuration has many nooks and crannies for the alert portion of the setup, I want to mention that configuring a service for monitoring is as easy as checking the NT service option during job setup. Then, you provide the IP address of the server where the service lives, and from the drop-down list, select the service you wish to watch.

A word of warning from personal experience…

If you have a WAN in your environment that uses a dynamic broadband connection working with a virtual private network—a cable modem, for example—and you choose to allow IP Sentry to monitor across this connection, be prepared for many alerts if anything happens to the wire connecting the remote location to the Internet.

Open the IP Sentry Interface by clicking the eye icon in the system tray. This will show a context window displaying the last scan results, as shown in Figure A. It also shows a countdown of the time remaining until the next scan takes place. This is all well and good, once the application is configured, but first you have to set the configurations.

Figure A
The main monitoring window of IP Sentry

At first glance, IP Sentry is really nothing flashy. The majority of the power and usefulness is behind the scenes in the configurable options. Choose Edit from the application menu at the top of the window. From there, select Options. This will open the configuration screen shown in Figure B.

Figure B
IP Sentry has many configurable options.

On the System Settings tab of IP Sentry’s Options page, there are four subtabs that apply to global or all-purpose options you should consider:

  • General
  • Logging
  • Remote Access
  • Statistics

On the General tab, you can configure options such as the scan interval, which allows you to specify the length of time between scans. The default for this option is five minutes. This is good for many situations, especially if you have only a few things to monitor. If you are monitoring a lot of devices you may want to extend this to allow more time to pass between checks.

You can also specify the timeout for each action. This will help reduce the time IP Sentry spends checking a device or service if it is down or potentially unavailable.

The next few settings on the General tab relate to the startup of IP Sentry. These are:

  • Launch At Startup tells the application to start with windows.
  • Start Minimized starts IP Sentry with the system tray icon open and no windows.
  • Retain Counters keeps the count from the previous launch of the software.
  • Startup Delay counts the specified number of minutes and then launches the IP Sentry application; this would be somewhat helpful if you wanted to delay the startup until after other services have started. For example, if all the other applications that were told to start on load took three minutes on average to get running, you could pause IP Sentry for three minutes, allowing everything else to get going prior to its launch.

There is also an NT Service Settings button on the General tab. Clicking it will display settings specific to running IP Sentry as a service under Windows NT. The NT Service Settings window is displayed in Figure C.

Figure C
Specify the logon credentials and install IP Sentry as an NT service.

To load IP Sentry as a service, click the Install Service button. This will load the service into Windows. Supply the proper login credentials for the service—usually a domain admin account, or local administrators group account will work the best for this. Typically, you will want to use the login of an account whose password doesn’t change too often to eliminate maintenance when the password is changed.

Perform a little preventive maintenance now to save time in the future

Because IP Sentry can send e-mail alerts to both e-mail accounts and alphanumeric pagers, you may want to create an account specifically for IP Sentry with high enough permissions to get the job done. Usually, a power-user type account with permission to log on as a service will do the trick. Set the password to Never Expire. This will lower the amount of maintenance needed when passwords get changed. You will want to change the password on this account occasionally to prevent it from being compromised.

After you have supplied credentials for the service to use, click the Stop/Start button on the Service Settings dialog. This will kick off the service and get the monitoring rolling.

You will also want to consider how the service should be started—manually or automatically. Since the purpose of the software is to alert you of any outages, I would select the Automatic option so that it starts with Windows and begins monitoring immediately.

The last option on the NT Service Settings page is the Self Monitoring option. This will allow IP Sentry to reload itself if there is no activity for the specified number of minutes.

After you have everything configured to run IP Sentry as a service, click the Finish button to return to the General tab.

The Logging tab will allow you to specify settings to keep track of what IP Sentry is doing and should assist you in any troubleshooting, if the need arises. Figure D shows the Logging subtab under System Settings.

Figure D
You can log activity here.

On this tab you can specify options for logging the actions taken by IP Sentry. If you wish to turn off logging altogether, check the Disable Logging box at the top of this tab. It is advisable for the first few scans to enable logging just in case things do not quite work right. Some of the options for logging include:

  • The number of days to keep log files (assuming there is a new log file for each day).
  • The path for the log files.
  • Application, monitoring, and alert information, which will keep track of IP Sentry application information.
  • Device and service monitoring information.
  • Fired alert information.

You can also add a header row to the log file so that it is easier to read the logs when you need them. Logging the settings in IP Sentry may seem somehow redundant since it is designed to let you know if there are any downed devices on your network, but they will prove to be very handy in troubleshooting and reviewing the details about when a device or service malfunctioned.

The next subtab on the System Settings page is the Remote Access tab. This section allows you to set IP Sentry to be accessed on a specific port of its host server’s IP address. This will allow you to configure another server on your network with IP Sentry and set it up to monitor this installation of IP Sentry. That way, if something happens to the IP Sentry service, application, or server, you will be notified by a backup server that is also running IP Sentry. You can also specify the telnet settings for the application, as well as whether or not the interface is telnet-enabled. This would allow you to telnet into it as you might a router and change or read configuration information. The Remote Access tab is shown in Figure E.

Figure E
The Remote Access configuration settings for IP Sentry

The final subtab within the System Settings tab, Statistics, will allow you to produce an output report of the statistics maintained by IP Sentry. This will allow you to see quickly what the uptime and/or downtime was for each monitored device in a given time period. Usually the time period is since the last restart of the server and/or IP Sentry.

Remote Checking is a breeze

Though configuring IIS is beyond the scope of this article, there is no default format for the output file produced when the auto-output statistics option is enabled; you can place it in a password-protected directory on your IIS server and save the report as an htm file. This will easily allow you to view the uptime of your devices over the Internet.

You are also asked to specify how often you would like the output report to be produced. This can be anywhere from 1 to 99 minutes; if no option is set, the report is created every minute. At anytime you wish, you can run the report by clicking the Statistics tab’s Output Now button.