N-View FAQ, Tips & Tricks

  1. Q: I'm using N-View 3.0 or above. After starting the program, I get the message: "The attempt to open a raw socket for sending ICMP-packets was refused by your system. As a workaround, the native "ping"-command is used. But for better performance you should use N-View with root/administrator privileges." What does this mean?

    2. A: Since version 3.0 N-View uses a JNI-library for sending and receiving ICMP-packets. The has the advantage of needing significant less system resources. The disadvantage is, it must be started with root- or administrator-permissions. Therefore N-View tests on start, whether it has those privileges and puts out this message if not. In this case, it uses the native "ping"-command of your operating system, like previous versions. You can use N-View this way, but need more system resources. In larger networks, starting N-View with root- or administrator-permissions is highly recommended.

  2. Q: I'm using N-View on Windows XP Service Pack 2. It seems, N-View can only monitor a little number of hosts. In the eventlog of my Windows system I can see a message: "TCP/IP has reached the security limit imposed on the number of concurrent TCP connect attempts." What shall I do?

    3. A: Use the patch from "LvlLord". You can find it on http://www.lvllord.de. With this patch You can increase the limit for concurrent TCP connections. Simply test, what number of concurrent connections is needed for monitoring your network.

  3. Q: I have a subnet with many hosts. They are displayed overlapped, so I cannot see them properly. How can a subnet be split into more windows?

    4. A: You can split Your subnets to as many windows as You want, by simply changing the subnet address / mask values. Let's make an example: Assumed You have a subnet with base address 192.168.0.0 and a subnet mask 255.255.255.0 (24 Bit) and You want to have it split into 4 windows. Create a new subnet with base address/mask 192.168.0.0 / 26. You will get a window containing the hosts of address range from 192.168.0.0 to 192.168.0.63. Create a further subnet with base address/mask 192.168.0.64 / 26. You will get a further window, containing the host of address range from 192.168.0.64 to 192.168.0.127. Repeat this task with base address/mask 192.168.128 / 26 and 192.168.192 / 26.

  4. Q: I would like to have a host displayed on my subnet window, which has an IP address not belonging to the subnet's address range. How can I do this?

    5. A: You can have arbitrary hosts added to a subnet window, if You know its IP address. Open the "Subnet Properties Dialog", right click on any position inside the hosts table and choose "Add Host". In the following "Host Properties Dialog" type in the IP address of this host and click "OK". The host will be displayed in the current subnet window.

  5. Q: I want to display my own background picture in a subnet window. But the chosen picture file is displayed "deformed". What do I do wrong?

    6. A: Nothing is done wrong ;-). N-View "zooms" the background picture, to fit optimal the display. If the aspect ratio of Your background picture differs from the aspect ratio of the screen, the picture will be "deformed". Use a picture editor to change the aspect ratio of Your picture file.

  6. Q: I want to print my network diagrams. How do I get the best results?

    A: N-View "zooms" network diagrams while printing, to best fill the page format of the current printer. Depending of the aspect ration of the display, the page will be set up to "landscape" or "portrait". Best print quality can be reached, when N-View's window has the same size and aspect ratio as the page to be printed. On an A4- or Letter printer a good result is achieved, when N-View is displayed in "full screen" with a screen resolution of 1024 x 768 in "tabbed" view.

  7. Q: N-View creates dynamic HTML pages of my network in the "htdocs"-directory of my Appache HTML server. If I display the sites in my browser, I get "sliders" on the right and bottom edge, because the pictures are bigger then the browser window rectangle. How can I get the pages to fit?

    8. A: N-View creates the graphics exact in the same size as in it's display. Change the size of Your N-View window so, that Your HTML pages fit the browser's display. Vary the windows size until the "sliders" in Your browser disappear. Please note: N-View creates a new picture of a subnet after each "Check-Interval" (according to the subnet settings). So it may take some minutes to be done.

  8. Q: I want to start an external program, running on the command line, over the context menu of a host. After starting the program, it is displayed in the process table of my Linux system, but i don't get a terminal window with the command line program.

    9. A: You have forgotten to start Your program in a X-Terminal. The command line must read: "xterm -e <path_to_my_program> <other_arguments_for_my_program>". For exaple: If You want to connect to that host with SSH, invoke the following command line in "Host Properties | Connection": "xterm -e /usr/bin/ssh <IP_Address_to_host>" and check "Enable external Command".