Importing Network Topologies - Suraj @ LUMS

Chapter 10 Importing Network Topologies

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Imp.1

Overview

Overview You can create a network model in several ways. One method is manually, by dragging and dropping objects from the object palette into the Project Editor workspace. You can also use rapid configuration to quickly building a complete topology. A third method of creating a network model is to import it from an external data source—either a system that monitors your network, or one or more data files that describe it. Importing a topology ensures that the resulting network model corresponds to the existing network exactly. This chapter discusses the requirements and procedures for importing topologies from the following data sources: •

ATM text files

•

HP Network Node Manager

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XML files

If you have a license for the Multi-Vendor Import (MVI) module, you can also import topologies from the following data sources (see the Topology Import chapter of the Multi-Vendor Import User Guide for details):

Imp.2

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Router configuration data

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Tivoli NetView

Importing from ATM Text Files You can import topologies from ATM text files; OPNET Modeler also includes a preprocessor for converting WANDL files to ATM data. Before you can perform an ATM import, you must create the text files that describe the node models, node locations, link attributes and PVCs in your network. The following section describes these files and formats in detail.

Imp.2.1

Required Files and Formats The ATM import process requires four different files to create a network topology; importing data from WANDL requires a fifth file as well.

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Each line in the file describes a single model, node, link or PVC.

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Attributes in each line are separated by tabs.

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Importing Network Topologies

All ATM data files use these formatting conventions:

Importing from ATM Text Files

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The import process ignores any line beginning with a number character (#).

Required ATM Text Files Type

Description

Reference

Locations

specifies node objects and their geographic locations

Locations File Description on page 656

Nodes

node names and underlying models

Nodes File Description on page 657

Links

link interfaces, data rates and oversubscription (OS) factors

Links File Description on page 657

PVCs

description of ATM PVCs in network

PVCs File Description on page 658

model map

maps WANDL models to OPNET models (WANDL import only)

Model Map File Description on page 658

Locations File Description The locations file specifies a topology’s node objects and their geographic locations. The import process uses a database of US telephone area (NPA) codes and exchange (NXX) codes to physically place each node. If you specify the same NPA and NXX codes for multiple nodes, the import process creates a subnetwork object at the specified location and places the nodes in that subnetwork. Note: The import process only recognizes NPA and NXX codes within the continental United States. If you specify non-US or no codes for a node, the import process places that node in Canada by default. Locations File Example #Locations file uses the following format: #NODE NPA NXX #NAME CODE CODE #--------------------------------------------------------MD_1 240 497 MD_2 240 497 CA_4 408 563 NC_1

Using this code, the import process creates a node (CA_4) and places it in Santa Clara, California (phone number = (408) 563-XXXX); then it creates a subnetwork object in Bethesda, Maryland (phone number = (240) 497-XXXX),

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creates the MD_1 and MD_2 nodes, and places them in the Bethesda subnetwork. The NC_1 node has no area code or exchange; as a result the import process places this node in Canada. Nodes File Description A nodes file specifies the underlying models for node objects, as shown in the following example file. Nodes File Example #Nodes file uses the following format: #NODE NAME OPNET MODEL MD_1 LU_GX550_56s_a25_adv CA_2 FS_ASX-4000_1s_a64_adv default atm16_crossconn_adv # “default” is case-sensitive (all lower-case) ....

Keep in mind that the import process uses the locations file—not the nodes file—to actually create node objects in your network. You can specify a default model to use for nodes that are listed in the locations file but not in the nodes file. In this case, the import process will use the atm16_crossconn_adv model for all nodes listed in the locations file only. Links File Description Each line in a links file specifies the source/destination interfaces and oversubscription factors for each link in the network, as shown in the following example file. Links File Example #Links file uses the following format: #SRC DEST DATA OS OS OS OS OS #NODE NODE RATE CBR RT_VBR NRT_VBR UBR ABR #--------------------------------------------------------MD_1 MD_3 OC12 100 100 100 100 100 ... NC_2 MD_3 OC48 100 100 100 100 100 ....

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Note that the over-subscription factors (OS:CBR, OS:RTR_VBR, OS:NRT_VBR, OS: UBR and OS:ABR) are all expressed as percentages of the total bandwidth.


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PVCs File Description A PVCs file specifies the PVC definitions in your network, which are stored in the ATM PVC Configuration object of the resulting network model. PVCs File Example #PVCs file uses the following format: #PVC PVC PCR MCR SCR MBS #NAME SRC DEST CAT QoS (Mbps) (Mbps) (Mbps) (cells) #-----------------------------------------------------------------PVC_2 MD_1 MC_3 CBR CBR 1.0216 default 1.0216 0.0 ... PVC_4 CA_1 CA_2 NRT_VBR NRT_VBR 12.28 default 5.7240 200 ....

Model Map File Description A model map file translates WANDL model names to their OPNET equivalents, and is required only when importing data from WANDL software. Model Map File Example #Model map file uses the following format: #WANDL MODEL OPNET MODEL ASX4000 FS_ASX-4000_1s_a64_adv GX550 LU_GX550_56a_a25_adv Default atm16_crossconn_adv # “Default” is case-sensitive (upper-case “D”, rest lower-case) ....

Note that you can specify a default OPNET model, just as you can in a nodes file. If the import process encounters a WANDL model not “mapped” in this file, it uses the default OPNET model. Imp.2.2

Creating and Specifying Preprocessors OPNET Modeler includes a preprocessor that can convert WANDL file formats to ATM data. You can invoke this script during the import process, as described in Imp.2.3 Performing the Import . If you have ATM data files generated by other network programs, you may want to create your own custom scripts or programs to generate ATM description files that you can import into OPNET Modeler. In this event, you should ensure that your script/program produces four separate files that use the formats described in Imp.2.1 Required Files and Formats .

Imp.2.3

Performing the Import The following steps summarize the general procedure for importing your ATM data into OPNET Modeler.

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1) Create the data files that describe your network, as described in Imp.2.1 Required Files and Formats and Imp.2.2 Creating and Specifying Preprocessors . 2) Open the ATM Import dialog box. You can import your ATM topology in either of two ways: •

To import into a new scenario: choose Import From ATM Text Files in the of the Startup Wizard.

Initial Topology window

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To import into an existing scenario: from the Project Editor’s Topology menu, choose Import Topology ➧ From ATM Text Files. (Keep in mind that importing into an existing scenario will overwrite the original contents.)

Either action opens the Select ASCII Files dialog box, shown in the following diagram. Here you can specify the four text files that define the objects in your network.

Select ASCII Files Dialog Box

To specify a data file, click the Browse button for the corresponding file, then specify the directory and file in the Select File dialog box.


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3) If you are importing WANDL data, proceed to the next step. Otherwise click OK to import your topology. ➡ OPNET Modeler imports your ATM data, creates a network topology, and sets the relevant attributes in the nodes, links, and PVC configuration object. The import process is complete.

generated ATM topology

nodes in subnet (same NPA and NXX values specified in node locations file)

4) (WANDL import only) Choose WANDL to OPNET from the Preprocessor pulldown menu. Then click OK.

➡ The ATI Import dialog box opens.

You use this dialog box to specify the model map file (described in Model Map File Description on page 658). If your WANDL data includes Frame Relay PVC information, you can also choose to ignore this information or create ATM PVC equivalents in your network model.

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Importing an HP Network Node Manager Topology

5) (WANDL import only) Specify your desired map file and Frame Relay PVC options, as described in the previous step. Then click OK to proceed with the import. ➡ OPNET Modeler imports and converts your WANDL data, creates a network topology, and sets the relevant attributes in the nodes, links, and PVC configuration object. Imp.3

Importing an HP Network Node Manager Topology One of Modeler’s powerful features is the ability to import network topology files created by HP OpenView Network Node Manager.

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Configuring NNM and OPNET Before a network database can be imported into OPNET, NNM and OPNET must be configured to work in tandem. There are two steps to this procedure: •

adding the OPNET registry file to the HP OpenView registration directory

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configuring the HP OpenView server to recognize and accept connections from client machines that will use OPNET’s import capabilities

Note: Since configuration procedures occasionally differ between UNIX and Windows machines, instructions are provided for both. Adding the Registry File Typically you must be logged in as root to add the registry file, as the HP directory where it must be placed is read-only to users other than root. To add the OPNET registry file to HP OpenView (Windows)… 1) Go to the :\OpenView\registration\C directory on the HP OpenView host machine. 2) Copy the opnet.reg file from the /sys/hpov directory to the :\OpenView\registration\C directory.

C:\OPNET\

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Note: describes the directory that contains the OPNET release currently installed. The default for a Windows machine is:


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To add the OPNET registry file to HP OpenView (UNIX)… 1) Go to the /etc/opt/OV/share/registration/C directory on the HP OpenView host machine. 2) Copy the opnet.reg file from the /sys/hpov directory to the /etc/opt/OV/share/registration/C directory. Note: describes the directory that contains the OPNET release currently installed. Running from a Remote Host If NNM will be running off a remote host (server), the server must be configured to recognize users or machines that may connect to use OPNET’s import capabilities. Note: The following steps should be completed only if HP OpenView will be used remotely. To run NNM off a remote host… 1) If you are using UNIX, go to the /etc/opt/OV/share/conf directory on the host machine. If you are using Windows, go to the :\OpenView\conf\ directory on the host machine. ➡ Within this directory there will be three authorization files: ovw.auth, ovwdb.auth, and ovspmd.auth. These authorization files determine which users and what machines will be able to log onto the server machine and use OPNET’s import capabilities. 2) Open each authorization file in a text editor. Each authorization file is divided into two sections: a header section that explains how to use and configure the file, and a section where the remote client machines and users can be specified. 3) In the section where the client machines and users are specified, add any client machine name or user name using the following formats: •

For a particular client machine with a particular user logged on:

•

For any user on a particular client machine: +

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•

For any client machine with a particular user: +

•

For any user on any client machine: + +

For example, if your user name is OPNET and your client machine name is you would add the line

my_client,

my_client OPNET

to each authorization file. Note: Minus signs (-) can be used in the place of plus signs (+) to deny a particular client machine or user access to the HP OpenView server machine. 4) Save the changes made to each authorization file, then close the file. Note: At this point, if you have edited either the .auth files or moved the opnet.reg registry file and NNM was running, you MUST restart NNM for the changes to take place. Imp.3.2

Importing Network Databases There are two main processes necessary for importing an NNM network database. The first process, which will typically be performed only once, is to prepare the Network Node Manager software for import. This includes making sure that the network database files are in the correct directories, starting the necessary background services/daemons for NNM, starting the NNM utility, and finally configuring the network to be imported. Only after these configuration steps have been completed can the second process, the actual network import, be performed.

Imp.3.3

Preparing Network Node Manager This section steps through preparing Network Node Manager and the network database for import into OPNET. Note: Complete this section only if NNM has not already been started.

The first step is to ensure that the network database to be imported is located in the correct directory.

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Setting Up the Database Files


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To place the network database in the correct directory (Windows)… 1) On the machine running NNM, use Windows Explorer to go to the :\OpenView\databases directory. 2) Make sure the network database is located in this directory. If not, copy it to this directory. To place the network database in the correct directory (UNIX)… 1) On the machine running NNM, change to the /var/opt/OV/share/ databases directory. 2) Make sure the network database directory structure is located in this directory. If not, copy it to this directory. Note: For both Windows and UNIX, you may only use one network database at a time. If you wish to change the database you are using, you must shut down any services/daemons running in the background, remove the current database from the OpenView directory and replace it with the new database, then restart the NNM services/daemons. Starting Background Services/Daemons Once the network database has been placed in the proper directory, the NNM background daemons (UNIX) or services (Windows) must be started before running NNM. To start background NNM services (Windows)… 1) On the machine running NNM, click the Start button, then select Programs. 2) Select HP OpenView, then click on NNM Services - Start ➡ The NNM services start.

To start background NNM daemons (UNIX)… 1) On the machine running NNM, log on as root, then type ovstart at the command prompt. ➡ The NNM daemons start.

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Configuring Background Services/Daemons Now that the background services/daemons needed to run NNM have been started, setup will vary depending on whether an active or inactive network database will be imported. An active network database is a database from a network that is currently being managed by NNM, e.g. the import is taking place as the network is being managed. An inactive network database refers to a database from a network that is not currently being managed or from a network that is still being managed but the database is not current for the network. If an inactive network is being imported, the netmon service/daemon must be turned off so that it will not try to remove nodes from the database during import. Note: Follow this step ONLY if you are importing an inactive network database. To turn off the netmon service/daemon (UNIX and Windows)… 1) Open a command prompt window, then type ovstop netmon at the prompt. ➡ The netmon service/daemon on the host machine stops. Starting the Network Node Manager Now that the appropriate services/daemons are running, the HP OpenView Network Node Manager must be started. To start NNM (Windows)… 1) On the machine running NNM, click on the Start button, then select Programs. 2) Select HP OpenView, then click on Network Node Manager. ➡ The Network Node Manager starts.

To start NNM (UNIX)… 1) On the machine running NNM, log in as root, then type ovw at the command prompt and press .

Configuring the Network Database When the Network Node Manager starts, a new window opens on your machine. This window has an icon in it labeled Internet. Double-clicking on

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➡ The Network Node Manager starts.


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this icon opens a new window that shows the IP submaps of the network. Further double-clicking allows you to view various subnets and segments of the network. Whereas OPNET uses the concept of subnets, HP OpenView’s Network Node Manager has submaps. The two terms refer to the same concept, except that NNM’s submaps break down further into persistent submaps and transient submaps. A persistent submap and its contents are cached on disk. Thus, when you double-click on a persistent submap, its contents appear very quickly on the screen. On the other hand, a transient submap’s contents are not cached. This means that whenever you double click on a transient submap, NNM must build that segment of the network “on the fly”. Thus, it takes much longer for a transient submap’s contents to appear on the screen. Transient submaps are typically used when the network being viewed is too large to store all of its submaps and their contents in memory. Submaps can be manually set to be transient or persistent. To import a network database into OPNET, submaps must be persistent from the segment level on up. To set submap persistence to the appropriate level (Windows)… 1) In the window with the Internet icon, select the Map menu bar item, then choose Properties. ➡ A new dialog box labeled Map Properties opens. 2) Click on the Applications tab. Select IP Map from the list of configurable applications, then click on the Configure for this Map... button. ➡ The Configuration dialog box appears. 3) From the list of IP Maps, click on the On-Demand: To what level should submaps be persistent? option. 4) From the list of attributes that appears, select Segment Higher. Click OK.

Level

and

5) In the Configuration dialog box, click the Verify button. ➡ Network Node Manager will verify the new settings. When it has completed verification, click OK. 6) In the Map Properties box, click OK. ➡ You may see a dialog box showing the update of the network database, as all the transient submaps from the segment level on up become persistent.

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To set submap persistence to the appropriate level (UNIX)… 1) In the window with the Internet icon, select the Map menu bar item, then choose Properties. ➡ A new dialog box labeled Map Properties opens. 2) Click on the Configurable Applications select IP Map, then click on the Configure for this Map... button. ➡ The IP Map Configuration dialog box appears. 3) In the IP Map Configuration dialog box, scroll down to the section for OnDemand: To what level should submaps be persistent? 4) Click on the pull-down menu and choose Segment Level and Higher. 5) Click the Verify button. ➡ Network Node Manager will verify the new settings. When it has completed verification, click OK. 6) In the Map Properties box, click OK. ➡ You may see a dialog box showing the update of the network database, as all the transient submaps from the segment level on up become persistent. Now that both NNM and the network database have been properly configured, the import process can be completed. Imp.3.4

Performing the Network Import Once both NNM and the network database have been correctly configured, the network database can be imported into OPNET. This process can be broken down into two parts: the actual network import, and the resolving of any questions that might occur during import.

Importing the Network

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The first part of the process, the actual network import, takes place in a scenario in OPNET. Once OPNET has been started, create a new project and a new scenario. You do not need to use the Startup Wizard to create the new scenario (although you can start the import process from the Startup Wizard), as the spatial properties of the network are maintained during import. You are now ready to import the network.


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To import the network… 1) Select From HP Network Node Manager (Network menu ➧ Import Topology submenu). ➡ The Import HP OpenView NNM dialog box opens.

There are several important options in the Import dialog box: •

NNM Server—The name of the machine running NNM.

•

Select Subnet—A hierarchal view of the network and all its subnets and their contents. To open a subnet, left-click on the plus sign next to the subnet. To select a subnet, left-click on the name of the subnet (the name will be highlighted to indicate selection). The top subnet is always called Internet.

•

LAN Aggregation—The level to which the LAN is aggregated or condensed. Choosing NONE means that none of the network will be aggregated. Selecting Subnet Level means that any objects at the network submap level will be condensed into a single object. Selecting Segment Level leaves objects at the network submap level as is, but condenses any objects at the segment submap level into a single object.

•

Advanced— If advanced is not checked, options below will not be visible.

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•

Repair Unstructured Subnets—Allows OPNET to attempt to make a network’s topology more realistic. If NNM cannot discover a device correctly (typically because the device is not running SNMP), the submap created in NNM may not have a realistic topology. Using this option when importing the network into OPNET will make the network topology more realistic. Repair Unstructured Subnets Example

NNM Network before import. Note the unlikely topology of six hubs and one switch around the network segment.

NNM Network after import into OPNET with Repair Unstructured Subnets option selected. Note the more likely topology of 6 hubs and their segments in a star conﬁguration around a central switch.

Within the Repair Unstructured Subnets option, the maximum and minimum number of ports per hub can be specified. Setting either of these check boxes will rearrange the switches into a logical binary tree to ensure that the user-defined criteria are met. Use NNM Icons—Instructs OPNET to use the Network Node Manager icons to represent the network objects instead of using OPNET icons.

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Use all known alias files—Instructs OPNET to use all alias files available. If not checked, the Aliases button will be available. Clicking on the Aliases button allows you to choose which alias files to apply to the import. For more information on aliases, see the Completing the Import section in the Importing Network Traffic chapter.

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Use all Question/Answer databases— Instructs OPNET to use all Question/Answer databases available. If not checked, the QADBs button will be available. Clicking on the QADBs button allows you to choose which Question/Answer database files to apply to the import. For more information on aliases, see Resolving Unanswered Questions on page 670.

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2) Set the NNM Server option to the machine on which NNM is running. If you are not sure how to specify this machine: a) On the machine running NNM, click on the Help menu item in any of the NNM windows, then select About OpenView. b) In the information about the machine, there will be a line labeled Session ID. This string is the ID of the machine running NNM. Use this string in the NNM Server field in the Import HP OpenView dialog box. Note: If the NNM Server is set incorrectly, the message “Cannot open connection to session . OVW not running.” will appear. If you receive this error message, check to make sure that NNM is running on the machine you specified, and that the machine is specified correctly in the NNM Server field in the Import HP OpenView NNM dialog box. Also, make sure that the machine is locatable via /etc/hosts or via DNS. See Troubleshooting the Import Process at the end of this chapter for more information. 3) Select the segment(s) you wish to import. ➡ The segment is highlighted to indicate that segment and all its contents have been selected for import. 4) Change the LAN Aggregation level to the appropriate setting. 5) Set the Repair Unstructured Subnets option, if desired. 6) If you wish to use NNM icons, check the Use NNM Icons box. 7) Click OK. ➡ The network begins import and status messages appear in the message box. Once the import has completed, either an “import complete” message will appear in the message box, or the Import Completed dialog box will appear, indicating that there were questions generated during import. If there are no questions, the network import is complete and the network may be loaded with traffic and used to run simulations. Otherwise, all required questions should be answered before the network is used in simulations. Resolving Unanswered Questions Occasionally the import process will generate questions about some of the network objects. These questions are stored in the Question/Answer (Q/A)

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database, which you will be prompted to open after the import has occurred. To answer these questions immediately, click OK in the Import Complete dialog box. Import Complete Dialog Box

If you decide that you want to answer these questions at a later time, click can open the Q/A database at any time by choosing Open… from the Topology ➧ Question/Answer Database submenu. Cancel. You

When the response database is first opened, the only subnet showing will be the top subnet, which corresponds to the top subnet in OPNET. Clicking on the plus sign next to the subnet name will open that subnet and show its children. Question/Answer Database Browser

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Within each subnet there may be other subnets or network objects. For this network, we see several links and segments. Within the segments are more links and network nodes, and within each node is an interface. Each network object is assigned a color, which reflects its status in terms of questions that were generated


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during import. Green objects have no questions, whereas red objects do. Yellow objects are subnets or nodes that have objects within them that have questions.The Filter setting determines which nodes are displayed. Since the Needs Attention filter is the default, only red and yellow objects appear in the browser window when it first opens. (Selecting the All filter displays all objects—red, yellow, and green—in the browser window.) The next step in the import process is to answer any questions about the network objects. To answer a question about a network object… 1) Open the Q/A Database, either by clicking OK on the Import Complete dialog box immediately after the network has been imported, or by choosing Open… (Topology menu ➧ Question/Answer Database submenu). ➡ The Q/A Database opens, showing the top subnetwork. If the top subnet is green, there are no questions about any objects in the network. Otherwise, there are questions to be answered about one or more network objects. 2) Apply a filter to the database if appropriate (for more information about filters, refer to The Filter Function on page 675). 3) Click on the plus next to the top subnetwork or node object to view that object’s children. 4) Continue clicking on the plus next to the yellow subnetwork objects until you see one or more red objects. There are two types of questions that can occur when a network is imported. The first type occurs when an object is imported but there is no matching node model that OPNET can associate with the object. This can be corrected by overriding the node model that has been chosen for the object (which will be NONE) and selecting a new node model manually or creating a node with Device Creator. The other type of question occurs when there is no matching machine or interface type that corresponds to the object. This question can be answered by defining the correct machine or interface type for that object.

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To override the node model for an object… 1) Right-click on the red object whose node model you wish to set. ➡ The Response Characteristics dialog box appears.

2) Click on the Override node model check box, then click on the Select Model button. ➡ The Set Model dialog box appears.

3) Select a model list from the first pull-down menu, then select the name of the model you want from the second pull-down menu. Click OK when you have set the model name. ➡ The node model name in the Response Characteristics dialog box will change to the model you selected. 4) Click OK in the Response Characteristics dialog box.

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➡ The red network object will change to green, since all the questions about that object have been answered (unless one of the object’s children is red).


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To define the machine or interface type for an object… 1) Right-click on the red object whose machine or interface type you wish to set. ➡ The Response Characteristics dialog box appears.

2) Click in the machine or interface type field, then select a machine or interface type for the network object. 3) Once you have selected a machine type for the object, you must also select a corresponding node model. Refer to the previous section for detailed instructions. 4) When you have selected the machine type and a node model for the object, click OK. ➡ The object will turn green in the response database. Note: Although objects will no longer be red in the response database, they will not appear correctly in the network until the response database has been saved and the network is re-imported with the saved response database applied. The Group Assign Function Sometimes when one object has questions after import, all the objects of the same type will also have the same question. For example, an imported network might have an object that does not have an OPNET counterpart. Thus the node model for all objects of this type would be set to NONE, and all those objects would be red in the Q/A database. These objects can all have their questions answered at the same time by using the Group Assign function.

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To use the Group Assign function… 1) Left-click on each object whose common characteristic you wish to change, or click on an object with children to select the object and all its children. ➡ A checkmark appears on each object selected. 2) When all the objects have been selected, click on the Group Assign button. ➡ The Group Characteristic Assignment dialog box appears.

3) In the Group Characteristic Assignment dialog box, make the appropriate changes, then click OK. ➡ The characteristics will be set for each object that was selected. Note: Although objects will no longer be red in the Q/A database, they will not appear correctly in the network until the response database has been saved and the network is re-imported using the corrected response database. The Filter Function Another commonly used function is the filter tool. There are several filters that can be applied: All - Shows all the objects in the Q/A database (all the objects in the network).

•

Needs Attention - Shows only the yellow and red objects in the response database (those objects that have unset characteristics, and their parents).

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Required - Shows only the objects that have questions that must be answered for the network model to work properly.

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•

Importing from Router Configurations

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User-specified - Shows only the objects that have user-specified characteristics (has characteristics that have been modified by the user).

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Advanced - Provides several options for the user to specifically define the functionality of the filter.

To use the Filter Function… 1) In the Q/A Database, select a filter type from the pull-down list. ➡ The filter is automatically applied to the objects in the Q/A database. If you answer the questions about a particular network object, click on the Reapply Filter button to reapply the filter and remove the updated object from the response database. Imp.4

Importing from Router Configurations This import method requires the Multi-Vendor Import (MVI) module; see section Top.3 Importing Topologies from Device Configuration Data in the MultiVendor Import User Guide for details.

Imp.5

Importing from Tivoli NetView This import method requires the Multi-Vendor Import (MVI) module; see section Top.2 Importing Topologies from Tivoli NetView in the Multi-Vendor Import User Guide for details.

Imp.6

Importing from an XML file If you have created an XML file describing your network topology, or if you have edited an XML file that was exported from Modeler, you can import the network model using the Import Topology from XML file operation. The format required for XML files destined for import is specified in the Document Data Type (DTD) file that comes with Modeler. This file, network.dtd, is located in //sys/etc. To import a network topology from an XML file... 1) From the Network menu, choose Import Topology ➧ From XML file.... ➡ The Choose an XML file to import dialog box opens. 2) Choose the XML file that you wish to import and click OK. ➡ The network is imported and status messages appear in the message box.

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Troubleshooting the Import Process

Once the import has completed, either an “import complete” message will appear in the message box, or the Import Complete dialog box will appear, indicating that there were questions generated during import. If there are no questions, the network import is complete and the network may be loaded with traffic and used to run simulations. Otherwise, all required questions should be answered before the network is used in simulations. SeeResolving Unanswered Questions on page 670 for more information about resolving questions that arise during import. Note: The Import Topology from XML file operation can also be launched from the Startup Wizard by choosing Import XML from the Initial Topology dialog box. Imp.7

Troubleshooting the Import Process Traffic Graph Example

Because there are many possible system configurations, you may occasionally have difficulty importing topology or traffic data. The following sections describe the import log and the FAQ page at OPNET’s web site. Section Imp.7.3 HP OpenView Errors describes the various OpenView error messages that may appear in the status bar of the Project Editor window. Section Imp.7.4 Resolving Name Resolution Problems explains various solutions to name-resolution problems. Imp.7.1

Using the Import Log

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OPNET generates log messages during each import operation, and maintains an import log file for each scenario. The log file name includes the project and scenario names and ends with“.imp.log”.


Modeling Concepts

You can view an import log by choosing Topology ➧ Open Import Log. This opens an edit pad with information about imports for the current scenario. If desired, you can also edit the log to add comments or other information. Import Log

You can clear all entries in the scenario’s import log by choosing Topology ➧ Clear Import Log. You may want to do this to remove obsolete messages and keep the file manageable. Clearing the log file can also be useful when you are investigating an import error. You can clear the log and then reproduce the error; this ensures that all log entries relate to the most recent import operation. Imp.7.2

The OPNET FAQ Page For more information on troubleshooting, go to the OPNET Support Center page (www.opnet.com/support) and follow the “Frequently Asked Questions” link. Then search for “importing” or “NNM”. Note: Access to this database requires a valid User Community user name and password.

Imp.7.3

HP OpenView Errors When you perform a topology import from NNM, you must first connect to the machine running NNM. To do this, you would typically type that machine’s familiar network name in the NNM Server space in the Import HP OpenView NNM dialog box, then click Connect.

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Modeling Concepts


NNM Server field

Connect button

However, sometimes there are problems with the setup and you will be unable to connect to the NNM server. The error message that appears in the lower righthand corner of your screen is typically as follows: HP OpenView Error (). Unable to connect to server. The specified server is not running NNM, or permission is denied.

If you cannot see all of this error message, you can click the View Message Buffer button in the lower-right corner of the OPNET window. The HP OpenView error is the most important part of this error message. The following sections discuss some of the possible HP OpenView errors, and configurations that may cause these errors: HP OpenView Error (Permission denied) Some setup is required to import from NNM. Make sure you followed the setup directions in section Imp.3.1 Configuring NNM and OPNET . If you have already done so, please check the following:

2) Make sure the .reg file is in the correct directory ( /OV/registration) on the NNM server.

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1) In the .auth files on the NNM server, make sure the hostname/username permissions are set correctly for the machine from which you are trying to connect. Try setting the permissions to “+ +” if you are trying to connect to the NNM server from a remote machine. However, refer to Resolving Name Resolution Problems on page 682 before you set your permissions in this manner as there may be a name resolution problem.


Modeling Concepts

3) Make sure the .reg file is the correct version. If you are importing into version 5.x (regardless of which version of NNM you have) you MUST use opnet.reg. If you are importing into version 6.x or later (regardless of which version of NNM you have) you MUST use mil3.reg. 4) If OVW was running when the .auth or .reg files were edited or moved, OVW must be restarted for the changes to take effect. Stop all OVW services and restart them, then try importing again. To stop OVW services/daemons and restart them: Windows

a) Choose Start ➧ Programs ➧ HP OpenView ➧ NNM Services - Stop. You should see a dialog box showing the status of each service as it is stopped. b) Choose Start ➧ Programs ➧ HP OpenView ➧ NNM Services - Start. You should see a dialog box showing the status of each service as it is started. c) Stop the netmon service if necessary (that is, if you are NOT importing an active network) by selecting the service, then clicking the Stop button. UNIX

a) At a command prompt, type ovstop. You should see status messages as the different daemons are stopped. b) Once all the daemons are stopped, type ovstart. Again, you should see a status message as each daemon restarts. c) Stop the netmon service if necessary (that is, if you are NOT importing an active network) by typing ovstop netmon. HP OpenView Error (OVW not running) 1) Check to make sure the name you are specifying in the NNM Server area of the HP OpenView Import dialog box is the correct name of the NNM Server machine.

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Modeling Concepts


NNM Server name

If the familiar name is correct, you may need to use the name specified by the Session ID in NNM. To find the Session ID: a) On the NNM Server machine, click on the Help menu in any of the NNM windows, then select About OpenView. b) In the information about the machine, there will be a line labeled Session ID. This string is the ID of the machine running NNM. Use this string in the NNM Server field in the Import HP OpenView dialog box.

2) Check to make sure all the NNM services/daemons are up and running correctly. If they are not, stop all services/daemons, then restart them. 3) If all the services/daemons are up and running correctly, check to make sure NNM (Windows) or ovw (UNIX) has been started. 4) If all of the above procedures have been followed and you are still unable to connect to the machine running NNM, there may be a name resolution problem. Refer to Resolving Name Resolution Problems on page 682 for more information. HP OpenView Error (Connection to OVW lost)

1) If NNM was exited, but the services were left running and NNM was then restarted (e.g., if .reg or .auth files were edited or moved), you must close the HP OpenView Import dialog box and re-open it, then import again.

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Typically this error occurs only when you have already been connected at least once to the NNM server, but for some reason the connection has been lost.


Modeling Concepts

2) If NNM was exited AND the services were stopped, then the services and NNM were restarted (this might happen if you were moving topology database files around), you must exit the OPNET software and restart. HP OpenView Error (Cannot connect to database) 1) Check the Services entry on all machines involved in the topology import. Make sure that if there is a port entry for ovwdb, then it is 9999. The services are listed in: C:\Winnt\system32\drivers\etc\Services (Windows) /etc/services (UNIX) If there is an entry for ovwdb, it should be: ovwdb 9999/tcp If the port number is not 9999, the best workaround is to change it to 9999. Note that this may cause problems if you have both NNM and other network management software installed on the same machine. An alternative workaround is to set the environment variable OVWDB_PORT to the desired port. This overrides the service port lookup. 2) If the ovwdb entry is correct on both machines, there may be a name resolution problem. See Imp.7.4 Resolving Name Resolution Problems for further information. Imp.7.4

Resolving Name Resolution Problems Sometimes you may not be able to connect to the machine running NNM because of a name resolution problem. Machines on your network are identified by a hostname, and this hostname must map to an IP address. This mapping can be done by DNS (Domain Name Server), or through a “hosts” file on each machine. You may need to contact your system administrator to determine which name resolution method your machine uses. There are several steps to follow to check for name resolution problems. Should any of these steps fail, you should contact your system administrator to resolve the name resolution problem.

Can you ping all machines involved in the topology import? For both machines (that is, the machine running the OPNET software and the machine running NNM), you should be able to run the following tests. To do so, open a command window and type in the information in bold:

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Modeling Concepts


prompt% ping

(for example, % ping opnet_server.mil3.com) prompt% ping

(for example, prompt% ping opnet_server) prompt% ping

(for example, prompt% ping nnm_server.mil3.com) prompt% ping

(for example, prompt% ping nnm_server)

After each entry, you should see some information confirming that the ping command was successful, such as:

prompt% ping opnet_server.mycompany.com

Pinging opnet_server.mycompany.com [172.129.17.2] with 32 bytes of data:

Reply from 172.129.17.2: bytes=32 time