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This chapter describes how to configure the Link Layer Discovery Protocol (LLDP) in order to discover other devices on the local network.
This chapter describes how to configure the Link Layer Discovery Protocol (LLDP) in order to discover servers that are connected to your Cisco NX-OS device.
You can configure the Link Layer Discovery Protocol (LLDP) in order to discover servers that are connected to your Cisco NX-OS device.
Note System-message logging levels for the LLDP feature must meet or exceed Cisco DCNM requirements. During device discovery, Cisco DCNM detects inadequate logging levels and raises them to the minimum requirements. Cisco Nexus 7000 Series switches that run Cisco NX-OS Release 4.0 are an exception. For Cisco NX-OS Release 4.0, prior to device discovery, use the command-line interface to configure logging levels to meet or exceed Cisco DCNM requirements. For more information, see the Fundamentals Configuration Guide, Cisco DCNM for LAN, Release 5.x .
Note The Cisco NX-OS release that is running on a managed device may not support all of the features or settings described in this chapter. For the latest feature information and caveats, see the documentation and release notes for your platform and software release.
This section includes the following topics:
The Cisco Discovery Protocol (CDP) is a device discovery protocol that runs over the data-link layer (Layer 2) on all Cisco-manufactured devices (routers, bridges, access servers, and switches). CDP allows network management applications to automatically discover and learn about other Cisco devices that are connected to the network.
To permit the discovery of non-Cisco devices, the switch also supports the Link Layer Discovery Protocol (LLDP), a vendor-neutral device discovery protocol that is defined in the IEEE 802.1ab standard. LLDP allows network devices to advertise information about themselves to other devices on the network. This protocol runs over the data-link layer, which allows two systems running different network layer protocols to learn about each other.
LLDP is a one-way protocol that transmits information about the capabilities and current status of a device and its interfaces. LLDP devices use the protocol to solicit information only from other LLDP devices. Cisco DCNM can use LLDP to discover only servers that are connected to your device.
LLDP supports a set of attributes that it uses to discover other devices. These attributes contain type, length, and value (TLV) descriptions. LLDP devices can use TLVs to send and receive information to other devices on the network. Details such as configuration information, device capabilities, and device identity can be advertised using this protocol.
LLDP advertises the following TLVs by default:
Note For information on device discovery and manually binding devices to a server, see the Fundamentals Configuration Guide, Cisco DCNM for LAN, Release 5.x .
The LLDP feature supports stateless and stateful restarts. After a reboot or supervisor switchover, the running configuration is applied.
For more information on high availability, see the Cisco Nexus 7000 Series NX-OS High Availability and Redundancy Guide, Release 5.x.
One instance of LLDP is supported per virtual device context (VDC). You are automatically placed in the default VDC unless you specify otherwise.
For information on VDCs, see the Cisco Nexus 7000 Series NX-OS Virtual Device Context Configuration Guide, Release 5.x.
For information on VDCs, see the Virtual Device Context Configuration Guide, Cisco DCNM for LAN, Release 6.x.
The following table shows the licensing requirements for this feature:
The LLDP feature has the following prerequisite (for a full list of feature-specific prerequisites, see the platform-specific documentation):
LLDP has the following configuration guidelines and limitations (for a full list of feature-specific guidelines and limitations, see the platform-specific documentation):
The following platform supports this feature. For platform-specific information, including guidelines and limitations, system defaults, and configuration limits, see the corresponding documentation.
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Table 9-1 lists the LLDP default settings.
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This section includes the following topics:
Note Cisco NX-OS commands for this feature may differ from Cisco IOS commands for a similar feature.
You can enable or disable LLDP globally on Cisco Nexus 7000 Series switches. You must enable LLDP globally to allow a device to send and receive LLDP packets.
Note LLDP is enabled globally on Cisco Nexus 5000 Series switches and cannot be disabled.
Make sure that you are in the correct VDC. To switch VDCs, use the switchto vdc command.
Step 1 From the Feature Selector pane, choose Interfaces > Physical > Ethernet. The available devices appear in the Summary pane.
Step 2 From the Summary pane, click the device on which you want to enable or disable LLDP.
Step 3 Do one of the following:
Step 4 From the menu bar, choose File > Deploy to apply your changes to the device.
This example shows how to enable LLDP globally on the device:
After you globally enable LLDP, it is enabled on all supported interfaces by default. However, you can enable or disable LLDP on individual interfaces or selectively configure an interface to only send or only receive LLDP packets.
Note If the interface is configured as a tunnel port, LLDP is disabled automatically.
Note Beginning with Cisco DCNM Release 5.1, you can enable or disable LLDP on individual interfaces on Cisco Nexus 5000 Series switches.
Make sure that you are in the correct VDC. To switch VDCs, use the switchto vdc command.
Make sure that you have globally enabled LLDP on the device. For more information, see the “Enabling or Disabling LLDP Globally” section.
2. interface ethernet slot/port
Step 1 From the Feature Selector pane, choose Interfaces > Physical > Ethernet. The available devices appear in the Summary pane.
Step 2 From the Summary pane, expand the device, expand the slot, and click the port on which you want to enable or disable LLDP.
Tabs appear for the port information in the Details pane. The Port Details tab is active, but its sections are not expanded.
Step 3 Do one of the following:
Step 4 From the Details pane, expand the Basic Settings section.
When LLDP is enabled, the LLDP Transmit Enabled and LLDP Receive Enabled fields show “ Enabled.”
When LLDP is disabled, the LLDP Transmit Enabled and LLDP Receive Enabled fields show “ Disabled.”
Step 5 (Optional) To selectively configure the port to only send or only receive LLDP packets, do one of the following:
Step 6 From the menu bar, choose File > Deploy to apply your changes to the device.
This example shows how to disable the transmission of LLDP packets on an interface:
You can configure the frequency of LLDP updates, the amount of time for a receiving device to hold the information before discarding it, and the initialization delay time. You can also select the TLVs to include in LLDP packets.
Make sure that you are in the correct VDC. To switch VDCs, use the switchto vdc command.
This example shows how to configure a hold time of 200 seconds, a delay time of 5 seconds, and an update frequency of 50 seconds as well as how to disable the port-vlan TLV:
Use the following commands to display the LLDP configuration:
Use the clear lldp counters command to clear the LLDP statistics.
This example shows how to enable LLDP on a device; disable LLDP on some interfaces; configure optional parameters such as hold time, delay time, and update frequency; and disable several LLDP TLVs:
For additional information related to implementing LLDP, see the following sections:
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No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature. |
Table 9-2 lists the release history for this feature.
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You can enable or disable LLDP per interface on Cisco Nexus 5000 Series switches. |
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