Preparing for Network Discovery

Table 2-1: Network Discovery Summary

Steps Action Purpose

Step 1

Upgrading Switch Software

To be sure that CWSI Campus works properly on your network, you should upgrade to the latest software versions.

Step 2

Enabling Cisco Discovery Protocol

CWSI Campus uses Cisco Discovery Protocol (CDP) to discover your network devices and layout.

Step 3

Enabling ILMI on ATM Devices

CWSI Campus uses Integrated Local Management Interface (ILMI) to discover the ATM devices in your network.

Step 4

Configuring VLAN Trunk Protocol

VLAN Trunk Protocol (VTP) is required to configure switches and display VLANs. If you want to display only the network topology, you do not need to enable VTP.

Step 5

Enabling ISL

If a switch is connected to Fast Ethernet links and you want to configure it to carry more than one VLAN, verify that Inter-Switch Link (ISL) is enabled on both sides of the link.

Step 6

Verifying Connectivity to Switches

The workstation on which CWSI Campus is installed must have connectivity to the switches in your network. If switches are not reachable, they will not be properly discovered and displayed on the CWSI Campus map.

Step 7

Modifying Community Strings

You must verify that the community strings are set properly to allow CWSI Campus access to your network devices. If you do not specify the right community strings, CWSI Campus cannot communicate with the device.

Step 8

Selecting a Seed Device

The seed device is the device from which you start the discovery process; it is required to begin discovery.

Step 9

Creating the Default LANE Configuration Server for ATM Devices

If you are running LAN Emulation (LANE) in your network, you need to set up the main configuration server.

Step 10

Installing and Starting CWSI Campus

You must follow the instructions for installing and starting the CWSI Campus applications before you can use the software.

Steps	Action	Purpose
Step 1	Upgrading Switch Software	To be sure that CWSI Campus works properly on your network, you should upgrade to the latest software versions.
Step 2	Enabling Cisco Discovery Protocol	CWSI Campus uses Cisco Discovery Protocol (CDP) to discover your network devices and layout.
Step 3	Enabling ILMI on ATM Devices	CWSI Campus uses Integrated Local Management Interface (ILMI) to discover the ATM devices in your network.
Step 4	Configuring VLAN Trunk Protocol	VLAN Trunk Protocol (VTP) is required to configure switches and display VLANs. If you want to display only the network topology, you do not need to enable VTP.
Step 5	Enabling ISL	If a switch is connected to Fast Ethernet links and you want to configure it to carry more than one VLAN, verify that Inter-Switch Link (ISL) is enabled on both sides of the link.
Step 6	Verifying Connectivity to Switches	The workstation on which CWSI Campus is installed must have connectivity to the switches in your network. If switches are not reachable, they will not be properly discovered and displayed on the CWSI Campus map.
Step 7	Modifying Community Strings	You must verify that the community strings are set properly to allow CWSI Campus access to your network devices. If you do not specify the right community strings, CWSI Campus cannot communicate with the device.
Step 8	Selecting a Seed Device	The seed device is the device from which you start the discovery process; it is required to begin discovery.
Step 9	Creating the Default LANE Configuration Server for ATM Devices	If you are running LAN Emulation (LANE) in your network, you need to set up the main configuration server.
Step 10	Installing and Starting CWSI Campus	You must follow the instructions for installing and starting the CWSI Campus applications before you can use the software.

Preparing for Network Discovery---Expanded Procedures

This section provides detailed steps for each of the procedures described in Table 2-1. To set up CWSI Campus, follow the instructions in these sections:

Upgrading Switch Software

Verify that your switches are running the latest system software versions. If you do not have the latest software version installed, you may not have the full functionality of CWSI Campus. If you want to take full advantage of CWSI Campus, you should upgrade your switch software to the latest software versions. Refer to the CiscoWorks2000 release notes for the latest supported versions. See the Essentials online help for instructions on downloading and installing the device software.

Enabling Cisco Discovery Protocol

Cisco Discovery Protocol (CDP) is a media- and protocol-independent device-discovery protocol that runs on all Cisco-manufactured equipment including routers, access servers, bridges, and switches. A device using CDP can advertise its existence to other devices and receive information about other devices on the same LAN or on the remote side of a WAN.

CDP enables CWSI Campus to retrieve the device-type and SNMP-agent address of neighboring devices. This allows CWSI Campus to send SNMP queries to the neighboring devices.

CWSI Campus uses CDP to discover and display the network topology. You must enable CDP on all devices in the network, except those at the boundary of your network, such as a gateway router that connects to devices outside your network.

To enable CDP, enter the following command on each switch:

set cdp enable all

Note This command and the other examples in this chapter are for Catalyst 5000 series switches. If you are using other Catalyst switches, refer to the Command Reference guide for the command on your specific switch.

Enabling ILMI on ATM Devices

Integrated Local Management Interface (ILMI) is an ATM Forum standard discovery mechanism that provides information about discovering devices on an ATM network at the ATM physical connectivity level. CWSI Campus uses ILMI to discover and display the ATM devices in your network.

Configuring VLAN Trunk Protocol

If you plan to use CWSI Campus to manage the VLANs in your network, you need to configure VLAN Trunk Protocol (VTP).

VTP is a layer 2 messaging protocol that maintains VLAN configuration consistency throughout the network. VTP manages the addition, deletion, and renaming of VLANs on a network-wide basis. VTP also allows you to make central changes that are automatically communicated to the other switches in the network.

If your network includes switches that support VTP, you need to follow the instructions in these sections:

Creating a VTP Domain

A VTP domain is made up of one or more interconnected devices that share the same VTP domain name. A switch can be configured to be in one and only one VTP domain.

VTP servers and clients maintain all VLANs within the VTP domain. A VTP domain defines the boundary of a particular VLAN. Servers and clients transmit information through trunks to other attached switches and receive updates from those trunks.

If you are using CWSI Campus in a Token Ring environment, you must use version 2 of VTP. If you do this, keep in mind that VTP version 1 and VTP version 2 are not interoperable on switches in the same VTP domain. Every switch in the VTP domain must use the same VTP version.

If you plan to use VTP version 1 in your network, go to Step 2.

Step 1 Enable version 2 of VTP by entering the following command on your switch before configuring the VTP domain:

set vtp v2 enable

Step 2 Configure the VTP management domain by entering the following command on the switch:

set vtp domain name

Replace name with the name of your management domain.

Setting the VTP Mode on the Switch

For each switch, you must decide which VTP mode to set:

Server---VTP servers advertise their VLAN configuration to other switches in the same VTP domain and synchronize their VLAN configuration with other switches based on advertisements received over trunk links. VTP server is the default mode.
Client---VTP clients operate the same way as VTP servers, but you cannot create, change, or delete VLANs on a VTP client.
Transparent---VTP transparent switches do not participate in VTP. A VTP transparent switch does not advertise its VLAN configuration and does not synchronize its VLAN configuration based on received advertisements.

The VlanDirector application requires at least one VTP server for each VTP domain. Other switches may be configured as VTP clients to participate in VTP, or may be configured in transparent mode, ignoring the VTP advertisements.

If you want to create a VLAN on the switch, you must place the switch in VTP server mode.

Step 1 Set the VTP mode by entering the following command on the switch:

set vtp mode server

Replace server with client if appropriate.

Step 2 Verify the VTP configuration by entering the following command on the switch:

show vtp domain

Note For additional guidelines about setting up VTP in your network, see Chapter 2, "Planning to Use the VlanDirector Application" of the Using the Campus VlanDirector Application publication.

Enabling ISL

Inter-Switch Link (ISL) is a Cisco-proprietary tagging protocol that allows VLAN trunking by maintaining VLAN information as traffic flows between switches and routers. ISL is used over Fast Ethernet VLAN trunks to carry traffic for multiple VLANs over a single link.

If a switch is connected to Fast Ethernet links and you want to configure it to carry more than one VLAN, verify that ISL is enabled on both sides of the link. By enabling ISL, you are configuring ISL ports, which are trunk ports. A trunk is a physical link that carries the traffic of multiple VLANs between two switches or between a switch and a router, allowing VLANs to be extended across the devices.

Note Refer to the specific software configuration guides for the devices in your network to learn how to enable ISL.

Verifying Connectivity to Switches

Ping each switch from the workstation on which you plan to install CWSI Campus to verify that you can reach each switch. This ensures that the workstation can effectively access and communicate with the devices on your network.

Modifying Community Strings

The community strings are text strings that act as a password and are used to authenticate messages sent between a management station and a device containing an SNMP agent. Community strings allow you to limit access to settings on your network devices.

You must verify that the community strings are set properly to allow CWSI Campus access to your network devices. If you do not specify the right community strings, CWSI Campus cannot communicate with the device.

The default community strings are "public" for the read-only string and "public" for the read-write string. If the community strings on your devices are different from these settings, you must edit the communities file manually before starting your first discovery.

Before editing the community strings, keep in mind the following:

The communities file allows you to specify wild cards based on IP addresses.

: You can add general strings, such as 10.*.*.* or specific strings for individual devices, such as 10.20.30.40. You can add a combination of general and specific entries, but the CWSI Campus application looks up the community strings from most specific to least specific.
: For example, consider the following entries in a communities file:

*.*.*.*:general::::::general:
10.*.*.*:Net10::::::Net10:
10.20.*.*:Net1020::::::Net1020:
10.20.30.*:Net102030::::::Net102030:
10.20.30.40:Device10203040::::::Device10203040:

Based on the information in this file, the community strings for devices in your network would appear as follows:

Device 10.20.30.40 has read and write strings of Device10203040.
Device 10.20.30.41 has read and write strings of Net102030.
Device 10.20.25.101 has read and write strings of Net1020.
Device 11.23.45.62 has read and write strings of general.

If you enter duplicate community strings, the CWSI Campus application ignores the earlier entry.
In addition to editing the read and write access of your devices, you can also modify the timeouts and retries.
Any changes made to the community strings from the CWSI Campus editor take effect immediately.
You can enter IP addresses or domain names, but wild card entries must be IP addresses.
Each line in the community strings file must have a colon (:) at the end.

To edit the community strings, follow these steps:

Step 1 Select Edit>SNMP Communities from the network map window.

Step 2 Enter the community string using this syntax:

target:read:UNUSED:timeout:retries:UNUSED:UNUSED:write:

When editing the community strings, you do not need to enter values for timeout or retries. If you do not enter values, they remain at the default settings:

timeouts=3 seconds and retries=3.

For example, if you want to edit the community string for the devices with the IP address 172.22.2.2, but you want to keep the default timeout and retries, enter:

172.22.2.2:public::::::public:

Step 3 If individual devices are configured with different community strings, enter new lines for each device.

Tips

You can also access and modify the community string settings by editing the communities.dat file directly instead of using the Edit>SNMP Communities menu command. This file is located in the <CWSIROOT>\etc\cwsi\ directory, where <CWSIROOT> is the install directory. The same guidelines apply regardless of how you modify these settings.

Selecting a Seed Device

A seed device is used to initiate discovery. Neighbors of the seed device are discovered using CDP or ILMI. You can specify more than one seed device, but for the initial discovery you can improve performance by limiting the number of seed devices you use. Also, although you can enter additional seed devices, keep in mind that CWSI Campus uses CDP to discover the devices in your network. Therefore, it is not necessary to add multiple seed devices.

If you plan to work with different VTP domains that are connected by routers, you should consider adding a seed device from within each VTP domain. Alternatively, you can extend the discovery boundaries across routers (see the "Changing Discovery Parameters" section in Chapter 3), but this can extend the discovery time considerably.

You enter the seed device during installation of CWSI Campus. Follow these guidelines for selecting the seed device:

The device must be a Cisco device.
Make sure that you can ping the device from the workstation on which you will run CWSI Campus.
Make sure that the device is reachable through simple network management protocol (SNMP).
Make sure that CDP is enabled on all link interfaces of the seed device.
Make sure that timeouts
are long enough.
- The default timeout is three seconds with three retries. For example, three second timeouts with three retries wait a maximum of nine seconds before reporting a timeout.
- Only read requests are retried.
- Each retry attempt doubles the timeout value (three, six, and twelve seconds using the default parameters).
If your network has ATM devices, use a LightStream 1010 switch or any edge device that supports ILMI (in ATM MIBs) as the seed device.

Note To change the seed device after installation, see the "Adding and Removing VTP Domains" section in Chapter 3, "Discovering Your Network".

Creating the Default LANE Configuration Server for ATM Devices

If you are using CWSI Campus to manage an ATM network, you need to create the default LANE configuration server.

ATM LAN Emulation (LANE) permits multiple logical LANs to exist over a single switched ATM infrastructure. ATM LANE emulates the Ethernet broadcast protocol over connection-oriented ATM. A LANE Configuration Server (LECS), LANE Server (LES), and Broadcast and Unknown Server (BUS) are required to make ATM work like Ethernet.

If your network contains ATM devices, create a default configuration server at each device in your ATM fabric using the device Command Line Interface (CLI). When you enable VTP on the ATM module, a default LANE client for the device is automatically created.

LightStream 1010 switches need a default LECS only if the Ethernet port is not used. If you create a LANE client on a LightStream 1010 switch, you need to assign an IP address to the switch.

I nstalling and Starting CWSI Campus

To install CWSI Campus, refer to the installation guide included with the product. The CWSI Campus installation is prompt driven and you need only to enter the name of your seed device. See "Selecting a Seed Device" for guidelines on choosing an appropriate seed device.

The installation guide also contains information about starting CWSI Campus. After you start CWSI Campus, the CWSI Campus map window displays the discovered network map, which includes all reachable discovered devices.

Table of Contents

Preparing for Network Discovery

Modifying Community Strings