FAQ: AutoDiscovery and Layout for Visio 2000

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Archived content. No warranty is made as to technical accuracy. Content may contain URLs that were valid when originally published, but now link to sites or pages that no longer exist.

Published: October 1, 2001

Technical Article

Visimation, Inc.
Microsoft Certified Partner

Applies to:
Microsoft Visio Enterprise 2000

Summary: This article answers frequently asked questions about the Microsoft Visio 2000 Enterprise Edition AutoDiscovery and Layout solution.

For the latest information, please see https://www.microsoft.com/office/visio

On This Page

Introduction
Changing shape mapping settings
Cisco switches support
Collecting additional SNMP (or other) information
Creating diagrams manually
Creating multiple AutoDiscovery databases
Customizing reporting tools
Discovering a device
Discovering layer 2 connectivity
Discovering layer 3 connectivity
How shapes are assigned
Importing an Enterprise 5.0 database file
Learning about AD&L
Manufacturer information and device description field
Missing devices on my network
Missing layer 2 connections
Network security issues
Non-router devices check box selection
Ping undiscovered devices check box selection
Report binders
Reporting templates
Routers check box selection
Rules that govern database naming
Running AutoDiscovery
Search router ARP caches check box selection
Sharing databases
Updating my AutoDiscovery database
Visio Network Equipment (VNE) shapes
Additional Information

Introduction

This article answers frequently asked questions (FAQ) about the Microsoft Visio 2000 Enterprise Edition AutoDiscovery and Layout (AD&L) solution. If you are just getting started with AutoDiscovery and Layout, the article Step-by-Step Guide to Diagramming your Network with Microsoft Visio Enterprise 2000 provides a simple walk-through of AD&L, including screen shots. The goal of this article is to provide sufficient information to help deploy AD&L in an enterprise or office environment. It is assumed that the reader has a basic knowledge of Visio 2000 Enterprise and is familiar with basic networking principles and protocols.

Changing shape mapping settings

Can I change the default settings used for mapping shapes to devices?

Yes. You can specify the shapes used for default network and device mappings. However, changes you make to the default mappings only affect new devices imported into your diagram, and device shapes currently in the diagram are not affected.

For example, use the following steps to change the default router shape so that a VNE Cisco751 (F) shape is used for all routers placed on a diagram.

  1. On the AutoDiscovery menu, point to Configuration, and then click Map Shapes.

  2. Select the Default shapes tab. In the Default Object Types list, select Router.

  3. In the Stencils list, click Browse, and then navigate to the Cisco Systems 1.vss stencil (C:\Program files\Visio\Solutions\VNE\Cisco Systems 1.vss).

  4. In the Shapes list, select Cisco751 (F), and then click Map. Now the Cisco751 shape will be used whenever a router is dropped onto the page.

Tips for mapping shapes

  • You may select and map several objects while on the Map shapes page, as the new settings are stored temporarily until you click OK.

  • You may specify a shape to use for a device on the Type shapes tab.

  • You may specify shapes to use for different network types on the Network shapes tab.

Cisco switches support

What Cisco switches does Visio 2000 support?

You can display virtual LAN (VLAN) and Spanning Tree information for selected Cisco Internetwork Operating System (IOS) switches supporting the proprietary Cisco Discovery Protocol (CDP).

Table 1 Supported Cisco Switches

Supported Switches

Software Version

Cisco 1900

7.02

Cisco 1900EN

7.02

Cisco 2820

8.01.00

Cisco 2900

2.1(8)

Cisco 3000

2.2(7)

Cisco 3200

2.2(4)

Cisco 4000

4.4(1)

Cisco 5000

2.2(2)

Cisco 5000

2.3(1)

Cisco 5000

3.2(1)

Cisco 5002

2.3

Cisco 5500

4.4

Cisco 5009

4.2

Cisco 8510

12.0(0.16)W5(3)

Collecting additional SNMP (or other) information

Does Visio 2000 Enterprise collect any Simple Network Management Protocol (SNMP) or other information beyond what is shown on the SNMP Device Detail Report?

Yes, but most of the information discovered is displayed in the report. For a complete description of everything in the AutoDiscovery database, see the following articles:

Creating diagrams manually

AutoLayout can create diagrams that are pretty complex. What's the best way to manually create diagrams?

There are two different methods to manually create a network diagram:

  • Use the Add Networks, Add Devices, and Connect Devices functions if you have limited knowledge of your network's configuration.

  • Use the Database Viewer if you are very knowledgeable of your network's configuration.

Both methods are discussed briefly below.

To add networks and connect devices

  1. Select Add Networks on the AutoDiscovery and Layout toolbar. In the Add Network dialog box, select the first network to place on your diagram.

  2. On the diagram, right-click the network and click Connect Devices from the shortcut menu to display a list of devices that are connected to that network.

  3. In the Connect Devices dialog box, select the devices to add to the diagram.

  4. Continue adding networks and devices to your diagram.

To use the database viewer

  1. Select Database Viewer on the AutoDiscovery and Layout toolbar to open the Database Viewer, which shows the contents of the active database.

  2. Select individual devices from the Database Viewer, and drag and drop them into place on your diagram.

  3. Right-click a device on the diagram and click Connect Networks, Connect Devices, or List Devices from the shortcut menu. For example, drag and drop a switch to the diagram. Right-click the switch and click Connect Networks to begin building your diagram.

You can view the properties of a device on the diagram by right-clicking a device and clicking Properties from the shortcut menu.

You can view switch connectivity information by right-clicking a switch and clicking Draw Connectivity from the shortcut menu.

Creating multiple AutoDiscovery databases

Why would I create multiple AutoDiscovery databases?

You can use the multiple databases feature to diagram specific portions of the network easily and efficiently without having to go through the entire network's data. Storing discovered data in separate databases also makes it easier for you to manage the database information, and it reduces the time required to perform the AutoDiscovery since discovery of large and complex networks can take many hours. If you are a consultant providing consulting services to multiple companies, create a separate database for each company for whom you work.

Tips on working with multiple databases

  • You must open the database before you can edit a diagram created from that database.

  • You can have multiple diagrams and databases open at the same time.

  • You can have Visio 2000 prompt you to choose the database to open when creating a new diagram. From the AutoDiscovery menu, select Configuration, and then click Manage Database. In the Manage Database dialog box, select the Show list of available databases when creating a diagram option, and then click OK. Each time you create a new network diagram, you are prompted to select which database to use.

  • You cannot delete a currently active database. Open a new or different database first, making it the active database.

  • If you do not assign a name, AutoDiscovery assigns the name of "ADL" to your first database.

Customizing reporting tools

What reporting tools come with AutoDiscovery? Can I customize the reports?

There are two methods to create network reports:

  • Generate Report Use this option to create context sensitive reports for a single device, or for multiple devices.

  • Report Wizard Use this option to generate multiple reports, to choose among devices to include in the report, and to view descriptions of each report template before you generate the report.

The Report Wizard provides a wider range of options than the Generate Report feature, including the ability to report on either an entire database or just selected devices.

To create a report using the generate report feature

  1. Open a network database and select a device on the diagram. Right-click the device and select Generate Report from the shortcut menu.

  2. Select a Report Template. In the Output Options section, select the Create As saved Visio documents option and navigate to where you want to save the report, and click OK.

To create a report using the report wizard

  1. On the AutoDiscovery menu, point to Network Reporting, and then click Report Wizard.

  2. You can also start the wizard by clicking Network Report Wizard from the AutoDiscovery and Layout toolbar.

  3. Select All shapes on the current page from the Choose the shape(s) on which to generate a report options. Click Next.

  4. Select a report from the Select one or more reports to generate list and click Next.

  5. Select Create As saved Visio documents from the Select How to Output The Reports(s) list, and save your drawing. Clear the Create report binder check box and click Finish.

Discovering a device

What happens on the network when a device is discovered?

AutoDiscovery sends several SNMP queries for device configuration information. If you select the Discover SNMP only devices option on the Discovery Wizard - Discovery Type page, devices that fail to reply to the SNMP request are ignored and no data is stored for those devices. If you select the Discover SNMP and non-SNMP devices option, a device's name, IP address, and possibly its media access control (MAC) address are stored in the database for each device replying to the SNMP request; this occurs for both SNMP and non-SNMP devices although more information may be gathered for SNMP devices. A MAC address is stored if it is discovered in an Address Resolution Protocol (ARP) cache; otherwise, the MAC address is recorded as 00:00:00:00:00:00 (the standard local area network (LAN) MAC address format). When a device responds to the SNMP request, AutoDiscovery attempts to resolve the Internet Protocol (IP) address to a name via an available naming service.

AutoDiscovery uses Microsoft Windows to resolve a name from a discovered IP address. Common naming services accessed via the Windows Sockets API include 1) the local system cache of host names, 2) the local hosts file, 3) Domain Name Server (DNS), and 4) Windows Internet Naming Service (WINS).

Discovering layer 2 connectivity

When does AutoDiscovery discover layer 2 connectivity?

Layer 2 connectivity is the port-to-port connections between two network devices. In some cases, multiple layer 2 connections exist between two devices. Layer 2 connectivity discovery does not include wide area network (WAN) or asynchronous transfer mode (ATM) connections.

AutoDiscovery determines layer 2 connectivity by analyzing the cumulative data collected from all routers and switches on the network; this is the final step of the discovery process. It is a multi-pass process that combines data provided from a variety of both standard and vendor-specific SNMP MIBs. Unfortunately, AutoDiscovery is not always able to gather the information necessary to completely identify layer 2 connectivity because the process is highly dependent on the presence of accurate and complete vendor implementations of standard SNMP MIBs.

Discovering layer 3 connectivity

When does AutoDiscovery discover the layer 3 connectivity?

AutoDiscovery determines how layer 3 devices are connected as each new device is discovered, using the IP addresses and subnet masks read from the device configuration information gathered during SNMP queries.

How shapes are assigned

Sometimes AutoDiscovery assigns the wrong shape to a device. How does AutoDiscovery decide which shape to use?

AutoDiscovery relies primarily upon the SNMP sysObjectID (see RFC 1213) value retrieved during the discovery process to determine a device's class or type, matching a device's sysObjectID to an internal list of published sysObjectIDs. If a match is found, AutoDiscovery assigns the device class associated with that sysObjectID.

If an unknown sysObjectID is returned, AutoDiscovery attempts to discern the device class by examining the SNMP sysDescription value for words like hub, router, switch, server, and so on. AutoDiscovery also queries to see if other standard Management Information Bases (MIB) reside on the device. For example, the presence of a Frame Relay (RFC 1513) MIB suggests the device is a router, whereas the presence of a Bridge (RFC 1493) MIB indicates the device is a bridge or switch. A standard SNMP MIB exists for hosts (RFC 1514) as well.

AutoDiscovery maps a device to a Visio Network Equipment (VNE) shape if the VNE library is installed on your system prior to running AutoDiscovery. If VNE is not present, AutoDiscovery maps a device to a default Visio 2000 network shape. AutoDiscovery maps a shape to a device at the time the device is added to a diagram.

Importing an Enterprise 5.0 database file

How do I import an Enterprise 5.0 Edition database file into Visio 2000?

You can retrieve the file using the Manage Database command. The file is automatically converted to Visio 2000 file format.

To retrieve the database

  • On the AutoDiscovery menu, point to Configuration and click Manage Database. Select the database you want to retrieve, and click Retrieve.

The Enterprise 5.0 Edition database is a group of files and not a single database. Enterprise 5.0 databases have file types of *.btr, whereas Visio 2000 database files have an .mdf extension. After you have retrieved the file, you must backup the Enterprise 5.0 database file before you can use them within Enterprise 2000.

To backup the database

  • On the AutoDiscovery menu, point to Configuration, and click Manage Database. Select the database you want to back up, and click Back Up.

Learning about AD&L

What's the best way to learn about Visio 2000 AutoDiscovery and Layout?

Start by using the Discovery Wizard to discover the devices on your enterprise network. It allows you to define where to start discovery, and how much of the network to discover. AutoDiscovery creates a database when it begins, and stores your network topology information in this database as device information is discovered.

Note: Unless you are a network administrator with knowledge of your network's SNMP configuration, consider running AutoDiscovery within a lab environment instead of on your corporate network.

After discovering your network, use the Network Diagramming Assistant to step you though the process of creating a network diagram. The Assistant's context changes to reflect the steps you need to take next as you create a network diagram.

To open AutoDiscovery and Layout

  • On the File menu, point to New, point to Network Diagram, and then click AutoDiscovery and Layout.

To start discovery

  • On the AutoDiscovery menu, point to Discovery, and then click Discovery to open the Discovery Wizard.

  • Work your way through the Discovery Wizard pages determining how much of the network to discover.

  • Start your search by discovering a small portion of your network. For example, configure AutoDiscovery to first discover only your routers and limit discovery by using the router hop limit. You can also limit your scope to only SNMP enabled devices.

To create a network diagram

  • When AutoDiscovery is finished, the Network Diagramming Assistant displays. Use it to help you create a diagram.

  • When you are familiar with adding devices and connectivity to the diagram, you can turn off the Assistant by selecting the Do not display this Assistant option.

Manufacturer information and device description field

What does AutoDiscovery use for the manufacturer information printed on the device detail report? What is used for the device description field?

AutoDiscovery uses each device's SNMP sysObjectID value to identify the SNMP enterprise value, which is shown in the Manufacturer field on printed reports. The VNE shape's description value is displayed in the Device Description field. In some cases, the enterprise identified by the sysObjectID value is a company that has been acquired or has licensed technology to another manufacturer. In these cases, you may see a manufacturer that does not match the name on the network device.

Missing devices on my network

Not all of the devices on my network are discovered. Why?

The following factors may affect AutoDiscovery's ability to discover devices**:**

  • Ensure that Transmission Control Protocol/Internet Protocol (TCP/IP) is installed on the workstation or server.

  • If the device is SNMP enabled, ensure the SNMP service is started and that it is enabled for Read-Only (RO) access, required by AutoDiscovery.

  • Ensure the SNMP community strings are correct, and that you are not missing any necessary community strings. Typically, "public" is the default community string, but many network administrators change this value for security purposes. You need to list all pertinent community strings.

  • Ensure that the device's IP address is within the range of addresses you entered on the Discovery Wizard Include Specific IP Addresses page, if you elected to enter address ranges.

  • Try to ping the specific device to see if it responds.

  • Investigate whether the network devices have access lists enabled to restrict the network managers (for example, source IP addresses) that can access the network devices.

  • Investigate whether the network devices have SNMP views defined that limit SNMP MIB access to specific network managers (for example, source IP addresses).

  • Investigate whether the device is on a Virtual Private Network (VPN).

  • Investigate whether the device sits behind a firewall.

  • Check the Enter SNMP and Ping Information values in the Discovery Wizard dialog box. The time-out settings for Ping and SNMP may be too short if you are attempting a discovery over a slow link, such as 128/256 WAN link.

  • Test the speed of the link by using AutoDiscovery to find a specific device by IP address or DNS name located in the subnet being discovered. Experiment by increasing the time-out settings to see if the device is responding too slowly.

Missing layer 2 connections

Why isn't AutoDiscovery finding all of my layer 2 connections?

Answering this question conclusively requires more information about your network and your AutoDiscovery configuration. However, AutoDiscovery may not be able to detect all of your layer 2 connections because:

  • The algorithms used to determine layer 2 connectivity are highly dependent upon the accuracy and completeness of the data within each device's standard and vendor-specific SNMP MIBs.

  • SNMP timeouts may prevent AutoDiscovery from having sufficient data to model layer 2 connectivity.

  • AutoDiscovery requires associating a unique MAC address with each bridge or switch port to correctly connect bridges or switches. However, many network switches only have unique addresses assigned to each port if Spanning Tree Protocol (STP) is enabled on the device.

Network security issues

Are there any security issues with using Visio 2000 Enterprise AutoDiscovery and Layout on my network?

It is recommended that you manage your Visio application server using the same security procedures you enforce for any other production application server. Most companies consider network information such as SNMP community strings to be sensitive data, and restrict access to this information to network administrators.

SNMP community strings are similar to passwords and provide a simple form of security for SNMP devices. The SNMP community string is used to authenticate SNMP messages received at an agent device, verifying that the sending management system has permission and is authorized to access the device's SNMP data. Community strings have levels of access permissions: None, Notify, Read Only, Read Create, and Read Write. AutoDiscovery requires access to an agent; otherwise, AutoDiscovery is only able to ping the device. RO access allows AutoDiscovery to read but not modify device information.

AutoDiscovery cannot sniff your network and does not capture network packets during the discovery process. AutoDiscovery does not alter the configuration of network devices.

AutoDiscovery uses Microsoft Data Engine (MSDE) as the local data store; its remote storage capabilities are not used. For more information on MSDE, search the MSDN Online Library for the articles "About Microsoft Data Engine (MSDE)" and "When to Use MSDE."

Non-router devices check box selection

What happens on the network when I select the Non-router devices option on the Discovery Wizard - Discovery Type page?

Selecting the Non-router devices option causes the Discovery Wizard - Discover Non-Router Devices page to be displayed. You can then choose Search router ARP caches, Ping undiscovered devices, or both.

Ping undiscovered devices check box selection

What happens on the network when I select the Ping undiscovered devices option on the Discovery Wizard - Discover Non-Router Devices page?

AutoDiscovery pings any addresses not discovered during the router or ARP cache discovery process. If a ping response is received, then AutoDiscovery attempts to fully discover the device using SNMP, following the process described in the Discovering a device section of this article. AutoDiscovery continues to ping any additional IP addresses, within the IP address bounds you specified.

Report binders

What are Report Binders?

You can use Report Binders to collect groups of reports and print a group all at once. The reports print with page numbers, as well as a table of contents and title page. Use Report Binder if you are printing a batch of reports for a notebook or if you have many reports to print simultaneously. The Report Binders window includes:

  • Report Binders A report binder indicates a set of reports. With a report binder selected, you can print the set of reports at once.

  • Dividers A divider represents a category within a set of reports. Each divider name appears on the table of contents page.

  • Reports The reports specified in each divider indicate the reports that are included in the report binder. The physical location of the report files is not changed by specifying reports here.

To manage reports using report binder

  1. On the AutoDiscovery menu, point to Network Reporting, and click Report Binders.

  2. In the Report Binders window, right-click the Report Binders icon in the tree view and choose Create Report Binder from the shortcut menu. In the Create Report Binder dialog box, enter a value in the Binder Name fieldfor instance, XYZ Network Reportsand click OK.

  3. Right-click the XYZ Network Reports binder and click Insert Report Divider from the shortcut menu. In the Insert Divider dialog box, type a divider name (for instance, SNMP Device Detail Reports), and click OK.

  4. Right-click the SNMP Device Detail Reports divider and click Insert Report from the shortcut menu. In the Insert Report dialog box, navigate to where your reports are saved and select an existing report fileyour SNMP Device Detail Report, for instance.

Reporting templates

What reporting templates ship with AutoDiscovery?

There is a wide range of predefined report templates enabling you to quickly inventory IP addresses, summarize frame relay data, track changes to your network topology, and more. The reports are generated as Visio drawing (.vsd) files, so you can easily publish them to the Web.

Table 2 Available AutoDiscovery and Layout Reporting Templates

Report Name

Report Summary

Cisco IOS Version

Lists the Cisco IOS version.

Device By Class

Lists the selected devices by class: routers, switches, printers, probes, servers, hubs, bridges, repeaters, and workstations.

Device by Manufacturer

Lists selected devices by manufacturer name.

Discovery Changes

Lists data from the initial discovery through the current day, with events categorized by device and listed in chronological order. It can be generated for the entire database or for selected network objects.

Duplicate IP Addresses

Lists information on devices with duplicate IP addresses, including the device names and MAC addresses.

Enterprise Summary

Summarizes the number of network objects.

Gateways by Subnet

List the gateways, or router interfaces.

Hosts by Subnet

Lists the workstations and SNMP devices discovered.

IP Address Inventory

Lists the IP Addresses stored in the database for selected network objects.

Port Blocking Summary

Lists the OSI Layer 2 (data link) port information for devices, including MAC addresses, speed, description, and forwarding or blocking state of the port. (Also found in Link Information for VLANs).

Printers By Subnet

Lists the printers found on the selected subnet.

PVC Summary

Lists the frame relay circuits found, including port, device, and endpoint information.

Router Detail

Draws the Visio Network Equipment (VNE) shape and lists information specific to the selected router(s).

Servers By Subnet

Lists the servers found on the selected subnet.

SNMP Device Detail

Lists basic information such as the manufacturer, device type, and location for the selected SNMP-configurable device.

Switch Detail

Draws the VNE shape and lists information specific to the selected switch(es).

Unused IP Addresses

Lists available IP addresses.

VLAN Extended Summary

Lists detailed information on each virtual LAN (VLAN) domain and VLANs discovered within the domain on your network.

VLAN Summary

Lists each VLAN domain, the VLANs discovered within the domain, their corresponding VLAN identifiers, and number of ports.

VNE Device Detail

Generates information on a custom or manually-added VNE shape that is not associated with a network object in AD&L.

Routers check box selection

What happens on the network when I select the Routers option on the Discovery Wizard - Discovery Type page?

AutoDiscovery starts the router discovery process by collecting data from the first router's route table. A route table is used to determine other routers known by that router. If you entered a specific router's IP address on the Discovery Wizard - Specify the Starting Router page, AutoDiscovery looks in that router's route table. Otherwise, AutoDiscovery starts by reading the default gateway router's route table.

AutoDiscovery sends a SNMP message containing a GetNextRequest to read a router's route table; the SNMP object referring to the route table is ipRouteTable. For more information, see RFC 1213, Management Information Base for Network Management of TCP/IP-based internets: MIB-II, available from the IETF website at https://www.ietf.org/rfc/rfc1213.txt?number=1213. Each reply to the GetNextRequest includes an ipRouteNextHop value, typically the IP address of another router on the network. For each new IP address returned as the ipRouteNextHop value, a new router is discovered. Each new router's route table is read in turn through this cycle until all routers are discovered.

Router configuration details and the subnets to which each router is connected are added to the AutoDiscovery database.

Rules that govern database naming

I am unable to use special characters, like a hyphen, in my database name. What rules govern database naming?

The underlying database engine, either MSDE or Microsoft SQL Server, enforces the database naming rules. Database names must adhere to the Transact-SQL identifier rules discussed in the following documents:

Running AutoDiscovery

What happens on the network when I run AutoDiscovery?

You can select different options when you run the Discovery Wizard and each option affects the sequence of events that occur within the AutoDiscovery process. For example, if you select only the Routers option on the Discovery Wizard - Discovery Type page, different discovery processes occur than if you also select the Non-router devices option, which displays the Discovery Wizard - Discover Non-Router Devices page.

There are two stages to the AutoDiscovery process. Layer 3 (Network Layer) SNMP discovery occurs first with discovery of the devices types (for example, routers, switches, and servers). Layer 2 (Data Link Layer) discovery occurs next, querying the discovered devices to determine how devices are connected to ports on a switch or router.

The following processes or steps can occur during the AutoDiscovery stages, depending on the configuration options you select:

  • Routers are discovered by querying route tables, beginning with the starting router.

  • Network devices are discovered by querying router ARP caches.

  • Layer 3 connectivity is determined.

  • Ping can optionally be used to discover additional devices not found within route tables or ARP caches.

  • Layer 2 connectivity is determined.

In addition, AutoDiscovery also uses the bounds you specified in the Discovery Wizard, such as the number of hops away from the starting router to search, SNMP and Ping retries or timeouts, and any IP address ranges or subnet masks entered.

SNMP is used during the AutoDiscovery process. AutoDiscovery acts as a SNMP management entity and sends SNMP requests to network devices. Network devices (for example, routers, switches, and servers) act as SNMP agents and reply to the SNMP requests with SNMP responses. AutoDiscovery, as the management system, queries any agent for which it has authorization, requesting values for specific variables such as known IP addresses held within a route table. SNMP is widely deployed by vendors and companies for management and monitoring of network devices.

Tips on using AutoDiscovery

  • Route tables can be quite big (for example, thousands of entries) within large, complex networks, yet they may contain relatively few unique IP addresses to discover. When you consider that SNMP GetNextRequests are sequential, querying one record at a time, it becomes obvious that size of a router's route table significantly affects the length of time required for discovery to complete. This process can be slow if you have many routers, each with a large route table.

  • All processes, such as router discovery and Address Resolution Protocol (ARP) cache discovery, occur within the bounds of the configuration terms you specify in the Discovery Wizard. This includes the SNMP and Ping retry and time-out values, the number of hops from the starting router, and any IP address ranges or subnet masks entered. You cannot limit the scope to n hops and restrict a search to an IP address range or subnet mask during the same AutoDiscovery process.

  • A range of addresses can be specified in two ways: by providing both a start and end address, or by providing a network address and subnet mask. You can use both methods within the same AutoDiscovery process.

  • If you elect to stop AutoDiscovery while within the layer 3 discovery process, you are prompted to continue discovery of your layer 2 devices.

Search router ARP caches check box selection

What happens on the network when I select the Search router ARP caches option on the Discovery Wizard - Discover Non-Router Devices page?

AutoDiscovery queries again each discovered router to read that router's ARP cache. An ARP cache contains the IP address and MAC address for each network device (switch, server, printer, and so on) known to a router.

SNMP GetNextRequest messages are again used to query each router's ipNetToMediaTable object (see RFC 1213) or ARP cache. Each SNMP reply generated by a router includes the ipNetToMediaPhysAddress, or MAC address, for each host on the network known to the router. AutoDiscovery learns the IP address and corresponding MAC address of each host on the queried router's subnet by sequentially reading the ipNetToMediaTable values. Any new device information, including subnet information, is added to the database enabling device connectivity to be modeled.

Note: Routers and other TCP/IP devices tend to remove unused ARP cache entries over time. Therefore, the ARP cache is not a complete representation of devices on the network. Instead, it only contains devices that have recently transmitted packets to a router for forwarding to another subnet.

Sharing databases

How can I share my database with a colleague?

You can make a copy of your database files using the Backup command. Using AutoDiscovery Backup detaches the database file from the server, allowing the files to be copied. This allows a measure of portability for AutoDiscovery databases by permitting multiple users to use the same data to diagram segments of the same network.

Database files reside only on the local machine from which you initiated your discovery, and are not directly shareable via an AutoDiscovery function. You can simply copy the database files from your system to another system since the database engine, either MSDE or SQL Server, has the database file open while the engine's service is running.

To backup a database file

  • On the AutoDiscovery menu, point to Configuration, and then click Manage Database. Select the database you want to back up, and click Back Up.

You must close an open database before backup is performed, otherwise the Back Up button on the Manage Database page is disabled (grayed out).

To use the copied files on the new Visio system after backup is performed on the local system

  • Copy the database files and, optionally, the AutoDiscovery diagrams to the new system.

To retrieve the database .mdf file on the new system

  • On the AutoDiscovery menu, point to Configuration, and then click Manage Database. Select the database you want to retrieve, and click Retrieve.

Note: The AutoDiscovery database engine is MSDE, which has the features and robustness of SQL Server. However, the backup facility on MSDE may not be sufficient to meet all needs. If this is the case in your environment, use the database administration tools and procedures found in SQL Server instead.

Updating my AutoDiscovery database

How do I update my AutoDiscovery database when changes are made to my network?

It is easy to update your database with recent changes. Run the Discovery Wizard, and on the Discovery Wizard - Discovery Type page, select either the Re-discover devices or the Ignore previously discovered devices options, depending upon whether the changes are to new or previously discovered devices. Select Re-discover devices if you want AutoDiscovery to rediscover all devices in your network.

There are several options in the Discovery Wizard to limit the discovery range:

  • Select the Ignore previously discovered devices option on the Discovery Wizard - Discovery Type page to ignore devices already in the AutoDiscovery database.

  • Select the Specific IP addresses option on the Discovery Wizard - Include page and then specify an IP address, DNS name, or a range of IP addresses to discover on the Discovery Wizard - Include Specific IP Addresses page. For example, select these options if new equipment is added to a building or subnet and you want to rediscover just that part of the network.

You can also exclude specific devices or IP address ranges from a search:

  • Select the Specific IP addresses option on the Discovery Wizard Exclude Specific IP Addresses page.

  • Enter an IP address, DNS name, or a range of IP addresses to exclude from discovery on the Discovery Wizard - Exclude Specific IP Addresses page. Consider whether you want to exclude your Dynamic Host Configuration Protocol (DHCP) address range, since DHCP clients are frequently workstations or servers, and their IP addresses may change on a regular basis.

An exclude specification takes precedence over items entered on the Discovery Wizard - Include page. For example, if you have specified a range of IP addresses to include and then enter a specific device's IP address to exclude, that device is not discovered. However, all other devices within the include range are discovered.

Visio Network Equipment (VNE) shapes

What are Visio Network Equipment shapes, and where do I get them?

VNE shapes are manufacturer-specific exact replica shapes. The VNE shape library has over 29,000 shapes from 500 different manufacturers, including 3Com, Cabletron Systems, Cisco Systems, Compaq, Hewlett-Packard, IBM, Intel, Leviton, Telcom, Lucent, Nortel Networks, and more. These shapes can be used on network diagrams to represent your network devices.

Each VNE shape has property pages associated with it. Depending on the device, the properties page can contain information about model numbers, manufacturer information, and device descriptions. The VNE information is stored in the Shape-Properties.mdb database. Visit the Microsoft Visio Network Center Web site to view and download new shapes as they become available.

VNE can be installed from the Visio 2000 Enterprise Edition Disk 2 CD.

Additional Information

The following resources provide more information on Microsoft Visio 2000 Enterprise Edition AutoDiscovery and Layout, and the networking protocols discussed within this article:

  • Microsoft Visio Network Center is a Web-based service on Microsoft.com where you can find the latest Visio network diagramming solutions, an up-to-date library of manufacturer-specific network equipment shapes, and case studies, white papers, and sample diagrams.

  • TechNet Technology Center for Visio

  • Visio Developer Center on MSDN Online

  • Visio 2000 Enterprise Edition User Guide.

  • Computer Networks & Internets, Douglas E. Comer and Ralph E. Droms, Prentice Hall Publications, 2001.

  • Interconnections, Second Edition, Radia Pearlman. Addison Wesley publisher, 1999.

  • Internetworking with TCP/IP, Vol. 1: Principles, Protocols and Architecture, Douglas E. Comer, Prentice Hall Publications, 2000.

  • Practical Guide to Snmpv3 and Network Management, David Zeltserman, Prentice Hall Publications, 1999.

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