Discovering Remote Devices

The Cisco Provider Connectivity Assurance Sensor Control is able to quickly and reliably discover the remote devices to be linked with an instance of the Sensor Control. These remote devices are extensions of the Sensor Control, providing it with the remote ports it needs in order to deliver system functionality. Use this page to specify the remote device discovery instances that were allocated to each Sensor Control instance.

Even if you have created discovery instances to specify how to discover the remote devices, it can happen that the Sensor Control finds more than just its own allocated devices. In order to associate and link only the appropriate devices with their intended Sensor Control instance, you can supply each instance of the Sensor Control with a predefined list of the remote devices that it is supposed to control. For details on adding a remote device or importing a list of remote devices in a CSV file, see "Adding Remote Devices".

There is no discovery mechanism in IPv6. The remote device's IPv6 address must first be configured using Cisco Provider Connectivity Assurance Module Dock. In Sensor Control, the remote device must be configured using static entry by configuring the same static IPv6 address that was configured using Module Dock. The IPv6 address can be configured with Sensor Control, but must first be managed using Layer-2 or IPv4 connectivity.

It is good practice to use only one discovery method for a specific remote device. If multiple discovery methods are being used, it is possibly that they will discover the same remote device. This can cause some confusion regarding the IP address being used to manage the unit, especially if a specific IP address is expected to be used for a specific remote device. It is important to note that the first discovery method used to discover the remote device is the one that will be used for management. For example, if DHCP advertisement is used at the time of an IP Agnostic discovery, then the IP address of that first method discovering the device is the one that will be used.

Configuring the Discovery of Remote Devices

There are two discovery methods you can use to configure and define remote device discovery
instances:

• IPAD: The IP Agnostic Discovery (IPAD) protocol, which is active between a Sensor Control and the remote devices. Supply an IP address assigned to a specific Sensor SFP 1G/Sensor Module 1G or other network device, or a subnet that will be scanned to discover all reachable remote devices.
• ACP Layer-2: The ACP protocol can be used to discover remote devices in Layer-2 networks.

▶ To discover remote devices

1. Access the page Discovery ▶ Configuration.
   The Remote Device Discovery Configuration page appears. A list of all remote device discovery instances is displayed.

2. (Optional) To limit the view to only certain instances, enter a value on which to filter, then click Search. You can filter by the instance name, method, rate or the state.

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   Note: Enter an asterisk () as a wildcard to replace one or several characters*.

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3. Click Add to create a new remote device discovery instance or click the Name of an existing instance to edit its settings.

4. Complete the required fields in the New Remote Device Discovery Configuration page.

5. Click Apply to save your changes.

For information on specific parameters, refer to the following section.

Remote Device Discovery Parameters (Discovery ▶ Configuration)

Name: A unique name assigned to the remote device discovery instance

Enable: Select this box to enable the remote device discovery instance

Method: The protocol to use when discovering remote devices

Available options are:

• IPAD: Suitable for both Layer-2 and Layer-3 networks
• ACP Layer-2: Layer-2 networks only

Rate: The frequency at which discovery messages will be sent over the network

Available options are:

• One-Shot: A one-time, single-use discovery message
• 3 Seconds: Discovery messages are automatically sent every three seconds
• 60 Seconds: Discovery messages are automatically sent once a minute. This is the default value.
• 5 Minutes: Discovery messages are automatically sent every five minutes
• 10 minutes: Discovery messages are automatically sent every ten minutes
• 60 minutes: Discovery messages are automatically sent every hour

Hop Limit: The maximum number of hops that the discovery messages can go through in order to discover remote devices

Default value: 255

Timeout (sec): The period of time after which the discovery messages sent by the Sensor Control instance expire. Use this parameter to have the Sensor Control stop listening for reply messages (advertisements) from remote devices.

The timeout value you choose must be less than or equal to the Rate value indicated above.

Default value: 10

Destination IP Address:An IP address assigned to a specific Sensor SFP 1G/Sensor Module 1G or other network device. You can also indicate a subnet that will be scanned to discover all reachable remote devices.

Type: The type and delivery scope of the Layer-3 discovery messages.

Available options are:

• UNICAST: Unicast discovery messages expect a host destination IP address assigned to a network device other than a Sensor SFP 1G or Sensor Module 1G.
• UNICAST-DIRECTED: Unicast-directed messages expect a destination IP address assigned to a specific Sensor SFP 1G or Sensor Module 1G. This type of discovery message is typically used to ensure a specific remote device is reachable.
• SUBNET: Subnet discovery messages expect a subnet destination IP address that covers an entire subnet where remote devices are located. This discovery type has the Sensor Control instance send out multiple unicast discovery messages to ensure that the entire subnet is covered.

The SUBNET discovery type requires a discovery message rate of at least 60 seconds. Setting a rate of 5 minutes is recommended. Applies to IPAD discovery instances only.

Interface: The logical (network) interface to use when discovering remote devices, such as LOCAL-2.

The logical interface is bound to the server’s local ports, meaning that the logical interfaces defined in Port ▶ Configuration are the same ones bound to the local ports.

Serial Number: Enter the serial number of a remote device here to create a probe limited to this specific device

Netmask: Enter a netmask subnet to be used on the destination address

The maximum subnet size is 23 bits (255.255.254.0), providing a total of 512 addresses.