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nPULSE - Frequently Asked Questions (FAQ)
 
This is the FAQ for nPulse. I've assembled some of the re-occuring questions and placed the answer/solution here. If you have difficulty with nPulse this is the FIRST place to check. If you can't find your answer here, feel free to send me an Email at npulse@horsburgh.com. The latest version of this FAQ is at http://www.horsburgh.com/h_npulsefaq.html. Also checkout the nPulse Developers Page. (This FAQ assumes that the defaults where used for file locations during setup.)

Contents

  1. What files do you keep the ip addresses and ports in?
  2. Why doesn't Email notification work?
  3. Why don't the "Basic", "Compact", and "List" displays update when I change a setting?
  4. How do I restart nPulse?
  5. I have ip and textual information already in another database (or program) can I import it into nPulse?
  6. Have you been considering providing any additional report generation functionality?
  7. Does nPulse work on Windows/95/98/NT/2000/etc?
  8. Is nPulse Pro currently available?
  9. How do I change the Admin password?
  10. Can I and How do I add/change/delete users?
  11. What is different between the "admin" user and a normal user?
  12. When I click on "Settings" and change something, the browser does something, then times out.
  13. Do I need to specify port numbers for all the ip addresses?
  14. How can I speed up the network scan?
  15. Does nPulse have Secure Sockets (SSL) support?
  16. Is there a quick way to determine "What's New" on my network?
  17. Can I change the device icon or operating system for a particular device?
  18. What triggers an Email report? Is an Email report sent when a port changes state?
  19. Can I send Email reports to multiple persons?
  20. Can I tie specific Email addresses to specific devices or groups of devices?
  21. Can I group equipment that belongs in the same network together? Can I limit the devices displayed on the overview pages?
  22. Does nPulse have SQL/database support?
  23. Can I add custom fields to the "Detail" Page?
  24. Can nPulse display hostname, alias, etc. instead of just the ip address on the "Basic, Compact, and List" screens?
  25. Can I limit user/admin access to nPulse to a specific IP address or sub-net?
  26. Why aren't UDP ports scanned?
  27. Can I customize the home page for users?
  28. What's the difference between nPulse and NetSaint or MRTG or ...?
  29. How can I generate my own PEM file for SSL?
  30. How can I change the Email messages sent?
  31. Why do scanned systems sometimes freeze/crash/restart/etc?
  32. Why do ports continue to show OK even though the port is closed?
  33. What is the most recent version of nPulse?
  34. Can I help with nPulse's development?
  1. Q: What files do you keep the ip addresses and ports in?

    A: IP address and port numbers are located in /usr/local/npulse/etc/configfile
    Most of the configuration files are located in the /usr/local/npulse/etc directory. You can edit this file either within nPulse (via the Setup button) or with your favorite text editor. You can also export an existing database/spreadsheet using the format:
    IPADDRESS<space>PORTLIST

  2. Q: Why doesn't Email notification work?

    A: Email notification is very sensitive to your sendmail setup. nPulse uses the Perl module: "Mail::Mailer" as the mail routine. First, make sure you have the most recent version of "Mail::Mailer" (# perl -MCPAN -e 'install Mail::Mailer'). Second, make sure that the Automatic Monitoring feature is enabled and that you have entered a valid email address. Third, make sure "autorecheck.pl" is running (via the Status Page). Lastly, the notification only takes place on the "next" automatic monitoring interval. So if you used the 20 minute default, it could be 40 (2 * 20) minutes before you receive a notification.

  3. Q: Why don't the "Basic, Compact, and List" displays update when I change a setting?

    A: The "Basic, Compact, and List" displays are generated by either the "AutoCheck" background process (when it finishes a run) or by clicking the "Recheck" button. Check the Status Page to see the status of the AutoCheck process.

  4. Q: How do I restart nPulse?

    A: As root issue the following command:
    # /usr/local/npulse/etc/restart
    Also you can stop/start nPulse using the following:
    # /usr/local/npulse/etc/stop
    # /usr/local/npulse/etc/start

  5. Q: I have ip and textual information already in another database (or program) can I import it into nPulse?

    A: Yes. There is a file that contains all of the name, email, phone, etc. It's called
    /usr/local/npulse/data/infofile.txt
    It contains the textual information for each device. The format is
    key1 => "value1", key2 => "value2", etc...
    one line per device with the "ip" and "os" and "icon" keys required.

  6. Q: Have you been considering providing any additional report generation functionality?

    A: Yes, I've considered it. No, it's not implemented yet.... (I'm also looking for suggestions).

  7. Q: Does nPulse work on Windows/95/98/NT/2000/etc?

    A: No, nPulse does not currently work on any Windows operating systems. Since nPulse uses NMAP as its network scan engine, it is only available for Linux and Unix operating systems. There are porting efforts underway for nmapNT (see www.insecure.org/nmap). When it becomes stable and fast enough, I'll look into porting nPulse to WinNT.

  8. Q: Is nPulse Pro currently available?

    A: nPulse Pro is not yet ready for public release. Currently I'm putting all of the features into nPulse Standard as freeware. Once the code stabilizes, has been tested on many system types, and documentation written, I will release the Pro version (which will probably have a price tag for support).

  9. Q: How do I change the Admin password?

    A: Use the utility "usermod":
    # /usr/local/npulse/usermod -m admin newpassword

  10. Q: Can I and How do I add/change/delete users?

    A: Use the utility "usermod" to modify/create/delete users and modify passwords.

  11. Q: What is different between the "admin" user and a normal user?

    A: Users other than "admin" will only be allowed access to the home, help, copyright, basic, compact, and detail pages. There is limited access to the detail page as well.

  12. Q: When I click on "Settings" and change something, the browser does something, then times out. Why?

    A: Most likely the "auto check" is on (running/sleeping) when you are making your changes in the Settings section. The best thing is to turn off "auto check" before you make any settings change and then turn it back on after you finish. The reason this happens is that if "auto check" is enabled and you make a change to any setting then the "auto check" process restarts and rescans the network, thus your timeout. Note that the process DOES continue to completion in the background.

  13. Q: Do I need to specify port numbers for all the ip addresses?

    A: No. If you only want status (up/down) information then leave the port numbers blank.

  14. Q: How can I speed up the network scan?

    A: Use groups (ranges) of ip addresses instead of single address values. nPulse runs **much** faster if you use ranges of ip address rather than a single entry for each address. For example 192.168.1.10-50 21,23,80 is about 20 times faster than single entries for each ip address.

  15. Q: Does nPulse have Secure Sockets (SSL) support?

    A: As of version 0.04p1 nPulse supports SSL.

  16. Q: Is there a quick way to determine "What's New" on my network?

    A: Using the "Ping Sweep" feature on the "Status Page" will provide information on what devices are responding that you are not currently monitoring. It also gives a quick overview status (up/down) of each of the devices.

  17. Q: Can I change the device icon or operating system for a particular device?

    A: Yes. Go to the "Details" page for the device. For icons, choose the icon from a pulldown menu and click "update". For the operating system, edit the OS: field. Note: only admin users can update this information.

  18. Q: What triggers an Email report? Is an Email report sent when a port changes state?

    A: An email report is sent when monitored devices (entire systems) OR individual ports transition from an "up" state to a "down" state or from a "down" state to an "up" state. If a device is "down" then only a device failure message is sent (to avoid sending multiple "port down" messages).

  19. Q: Can I send Email reports to multiple persons?

    A: Yes, simply set the email notification address to a group email account.

  20. Q: Can I tie specific Email addresses to specific devices or groups of devices?

    A: Yes, use the "Notify" field on a device's Detail Page for additional email addresses. Note: Email messages are always sent to the "admin" user.

  21. Q: Can I group equipment that belongs in the same network together? Can I limit the devices displayed on the overview pages?

    A: There are two ways to group devices: Sorting and Filters. The "Sort" feature (pull down menu) can sort the Basic, Compact, and List screens in a variety of ways. You might use the "Location" or "CustomerID" fields to specify your grouping and then sort. A more powerful grouping feature is the "Filter" capability. You can define filters (by groups of IP addresses) via the "Edit Filters" option in the pull-down menu next to the "Go" button in the upper right corner of the screen. Filters are shown on the Home page for quick access as well as in the "Go" pull-down menu.

  22. Q: Does nPulse have SQL/database support?

    A: No. I've had a number of good suggestions, but, I've not had time to delve too deeply into it yet.

  23. Q: Can I add custom fields to the "Detail" Page?

    A: Yes. Manually edit the "/usr/local/npulse/preferences.pl" file and add the fields to the variable $Templatetext. Template lines are of the form
    Name_Position => undef
    where "Name" is the field name (letters and digits only) and "Position" is the line number you want the info to appear on. For example: MyCustom1_9 => undef defines a field called "MyCustom1" displayed on line 9.

  24. Q: Can nPulse display hostname, alias, etc. instead of just the ip address on the "Basic, Compact, and List" screens?

    A: Yes. There are a number of ways to display the information on the Basic, Compact, and List overview pages. From the "Settings" page, choose "Configuration" and set the "UseAliases" value to one (1) and then set "CustomName" so that it displays the info you want.

  25. Q: Can I limit user/admin access to nPulse to a specific IP address or sub-net?

    A: Yes. Go to the "Settings/Web Server" page and enter the allowed addresses in the Access Control area.

  26. Q: Why aren't UDP ports scanned?

    A: nPulse does not automatically scan UDP ports. The reason is that UDP is a "non guaranteed" protocol. Which means nPulse might not get a response from a UDP service even though the service is available. Because of that nPulse would report false failures. You can manually scan the UDP ports using a "custom command" such as nmap -v -sU $IP$

  27. Q: Can I customize the home page for users?

    A: Customization of the home page for both regular users and admin users is available starting with version 0.40p5. There are two files: userwelcome and adminwelcome (in /usr/local/npulse) that contain the HTML that appears when the user clicks on the "Home" button. You can use these files to add custom instructions, company logos, system-wide messages, etc.

  28. Q: What's the difference between nPulse and NetSaint or MRTG or ...?

    A: It seems that the basic difference between the programs is complexity. nPulse is based on a much simpler architecture, quickly installs, automatically configures itself and the network (no manual configuration files!), does not rely on GD, uses Nmap for fast OS detection and network scanning, and is written in Perl. As for features, NetSaint and MRTG have many more features than nPulse. This is both a positive and a negative. Most user responses I've received say they like nPulse because of its simplicity, speed, and avoidance of "feature-itis." On the other hand, there are features in NetSaint and MRTG that are just not possible to perform in nPulse. Also nPulse is somewhat less resource intensive.

  29. Q: How can I generate my own PEM file for SSL?

    A: To create the miniserv.pem file do the following as root, in root's home directory:
    # /usr/local/ssl/misc/CA.pl -newca
    # /usr/local/ssl/misc/CA.pl -newreq
    # /usr/local/ssl/misc/CA.pl -signreq
    # openssl rsa -in newreq.pem -out req.pem
    # cat newcert.pem req.pem > miniserv.pem
    # rm newcert.pem newreq.pem req.pem

    • On the first command enter <return> to create a new CA and use a simple pass phrase. Answer all of the questions.
    • On the second command enter the previous pass phrase and answer all of the questions the same as in the first command. Leave "challenge" and "optional company" blank.
    • On the third command enter the previous pass phrase and sign and commit the certificate.
    • The fourth command deletes the pass phrase.
    • The fifth command creates the full ".pem" file (miniserv.pem)
    • The last command deletes the temporary files.
  30. Q: How can I change the Email messages sent?

    A: There is no "automatic" method of changing the Email message. You can, however, manually change the message by editing /usr/local/npulse/autorecheck.pl. Look for the line similar to print $mail "nPulse reports $event for $name [$ip]\n\nAt: $time\n"; Edit this line with your custom message. The subject line is the preceding line. Note that when upgrading nPulse this message will typically be overwritten, so you must make the change again.

  31. Q: Why do scanned systems sometimes freeze/crash/restart/etc?

    A: Typically the answer is speed. Nmap (which is nPulse's scanning engine) tries to scan the network as fast as possible, sometimes overwhelming scanned systems. Try slowing down the scan by using the -M option (-M 2) or --max_parallelism option (--max_parallelism 1) for nmap (See Settings/NMAP/nmap_extra_options).

    Note however, if nmap can adversely affect these systems then anyone outside or inside your organization (hacker or not) can do the same!

    Another method to prevent scanned system crashes is to limit the ports which are scanned to only those ports you are actually interested in. This not only speeds up nPulse, it also is easier on the scanned systems.

    A final method is to change the Settings/NMAP/NmapScan value from -sT to -sS. The -sS option is easier to handle on some systems.

  32. Q: Why do ports continue to show OK even though the port is closed?

    A: nPulse was written for nmap versions prior to 3. If you are using a newer version of nmap try the following:

    1. Stop nPulse (/usr/local/npulse/etc/stop)
    2. As root edit the file /usr/local/npulse/lib/util.pl
    3. Change line 89 from
            $site{ports} .= $p[0].',';
      to
           $site{ports} .= $p[0].',' if $p[1] =~ /open/i;
    4. Start nPulse (/usr/local/npulse/etc/start)

  33. Q: What is the most recent version of nPulse?

    A: The most recent stable and development versions of nPulse are at http://freshmeat.net/projects/npulse/ or www.horsburgh.com.

  34. Q: Can I help with nPulse's development?

    A: Of course! nPulse is Open Source. Suggestions, bug fix submissions, enhancements are always welcome. When submitting an enhancement or bug fix, please include the version number and if possible a "diff" file to npulse@horsburgh.com.

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