Configuration Guide for Cisco NCS 1014, IOS XR Releases 26.x.x

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Configuration Guide for Cisco NCS 1014, IOS XR Releases 26.x.x

Link Layer Discovery Protocol (LLDP) support on management interface

Updated: June 18, 2026

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This section explains the role and attributes of Link Layer Discovery Protocols (LLDP and CDP) when used on management interfaces, including their advantages, limitations, interoperability, and configuration options.

The LLDP can be configured on management interface of 1.2T, 2.4T, and 2.4TX cards. It requires a system to form LLDP neighborship over the system management interface, through which it advertises and learns LLDP neighbor information. This information about neighbors is used to learn about the neighbors and in turn the topology of the devices for Operations, Administration, and Maintenance (OAM) purposes.

Advantages of LLDP

  • Provides support on non-Cisco devices.

  • Enables neighbor discovery between non-Cisco devices.

Limitation

  • When you disable LLDP globally, the LLDP gets disabled on all the interfaces.

Note

By default, LLDP is enabled for NCS 1014. But when you enable and disable LLDP in the global configuration mode, LLDP gets disabled on all the interfaces.

Workaround : You must enable LLDP globally or reload the Router.

Cisco Discovery Protocol (CDP) vs LLDP

The CDP is a device discovery protocol that runs over Layer 2. Layer 2 is also known as the data link layer that runs on all Cisco devices, such as routers, bridges, access servers, and switches. This protocol allows the network management applications to automatically discover and learn about other Cisco devices that connect to the network.

The LLDP is also a device discovery protocol that runs over Layer 2. This protocol allows the network management applications to automatically discover and learn about other non-Cisco devices that connect to the network.

Interoperability between non-Cisco devices using LLDP

LLDP is also a neighbor discovery protocol that is used by 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.

With LLDP, the user can also access the information about a particular physical network connection. If the user uses a non-Cisco monitoring tool (through SNMP), LLDP helps you identify the Object Identifiers (OIDs) that the system supports. The following OIDs are supported:

  • 1.0.8802.1.1.2.1.4.1.1.4

  • 1.0.8802.1.1.2.1.4.1.1.5

  • 1.0.8802.1.1.2.1.4.1.1.6

  • 1.0.8802.1.1.2.1.4.1.1.7

  • 1.0.8802.1.1.2.1.4.1.1.8

  • 1.0.8802.1.1.2.1.4.1.1.9

  • 1.0.8802.1.1.2.1.4.1.1.10

  • 1.0.8802.1.1.2.1.4.1.1.11

  • 1.0.8802.1.1.2.1.4.1.1.12

Neighbor discovery

System advertises the LLDP TLV (Type Length Value) details over the management network using which other devices in the management network can learn about this device.

Configuring LLDP

  • LLDP full stack functionality is supported on all three management interfaces supported in NCS 1014.

  • You can selectively enable or disable LLDP on any of the management interfaces on demand.

  • You can selectively enable or disable LLDP transmit or receive functionality at the management interface level.

  • Information gathered using LLDP can be stored in the device Management Information Database (MIB) and queried with the Simple Network Management protocol (SNMP).

  • LLDP operational data are available in both Command Line Interface and netconf-yang interface.

Enabling LLDP globally

When you enable LLDP globally, all interfaces that support LLDP are automatically enabled for both transmit and receive operations.

Note

You can override this default operation at the interface to disable receive or transmit operations.

This table describes the global LLDP attributes that the user can configure:

Table 1. Global LLDP attributes

Attribute

Default

Range

Description

Holdtime

120

0–65535

Specifies the hold time (in sec). Hold time refers to the time or duration that an LLDP device maintains the neighbor information before discarding.

Reinit

2

2–5

Delay (in sec) for LLDP initialization on any interface

Timer

30

5-65534

Specifies the rate at which LLDP packets are sent (in sec)

Debugging LLDP issues

These commands are used for debugging issues in the LLDP functionality.

  • show lldp traffic

  • debug lldp all

  • debug lldp errors

  • debug lldp events

  • debug lldp packets

  • debug lldp tlvs

  • debug lldp trace

  • debug lldp verbose

Configure LLDP

Use this task to configure LLDP globally.

Before you begin

  • LLDP full stack functionality is supported on all three management interfaces supported in NCS 1014.

  • You can selectively enable or disable LLDP on any of the management interfaces on demand.

  • You can selectively enable or disable LLDP transmit or receive functionality at the management interface level.

  • Information gathered using LLDP can be stored in the device Management Information Database (MIB) and queried with the Simple Network Management protocol (SNMP).

  • LLDP operational data are available in both Command Line Interface and netconf-yang interface.

Procedure

Run the configure terminal command to enter the configuration mode.

Example:

This example shows the commands to configure LLDP globally. The global LLDP configuration enables LLDP on all the three management interfaces.


RP/0/RP0/CPU0:regen#configure terminal
RP/0/RP0/CPU0:regen(config)#lldp management enable 
RP/0/RP0/CPU0:regen(config)#lldp holdtime 30 
RP/0/RP0/CPU0:regen(config)#lldp reinit 2 
RP/0/RP0/CPU0:regen(config)#commit

Example:

This example shows the commands to configure LLDP at the management interface level.

RP/0/RP0/CPU0:ios(config)#interface mgmtEth 0/RP0/CPU0/X
RP/0/RP0/CPU0:ios(config-if)#lldp enable
RP/0/RP0/CPU0:ios(config-if)#commit

Example:

This example shows the commands to disable the LLDP transmit operations at the specified management interface.

RP/0/RP0/CPU0:ios(config)#interface mgmtEth 0/RP0/CPU0/X
RP/0/RP0/CPU0:ios(config-if)#lldp transmit disable
RP/0/RP0/CPU0:ios(config-if)#commit

Example:

This example shows the commands to disable the LLDP receive operations at the specified management interface.

RP/0/RP0/CPU0:ios(config)#interface mgmtEth 0/RP0/CPU0/X
RP/0/RP0/CPU0:ios(config-if)#lldp receive disable
RP/0/RP0/CPU0:ios(config-if)#commit

Verify LLDP configuration

Use this task to verify LLDP configuration.

Procedure

1.

Run the show running-config lldp command to verify the LLDP configuration.

Example:


RP/0/RP0/CPU0:regen#show running-config lldp
Tue Dec 10 10:36:11.567 UTC
lldp
timer 30
reinit 2
holdtime 120
management enable
!
2.

Run the show lldp interface and show lldp neighbors commands to verify the LLDP data.

Example:

RP/0/RP0/CPU0:regen#show lldp interface 
Thu Nov  7 08:45:22.934 UTC
MgmtEth0/RP0/CPU0/0:
        Tx: enabled
        Rx: enabled
        Tx state: IDLE
        Rx state: WAIT FOR FRAME
MgmtEth0/RP0/CPU0/1:
        Tx: enabled
        Rx: enabled
        Tx state: IDLE
        Rx state: WAIT FOR FRAME

Example:

RP/0/RP0/CPU0:M-131#show lldp neighbors
Mon Dec  2 11:01:20.143 CET
Capability codes:
        (R) Router, (B) Bridge, (T) Telephone, (C) DOCSIS Cable Device
        (W) WLAN Access Point, (P) Repeater, (S) Station, (O) Other
Device ID       Local Intf               Hold-time  Capability     Port ID
[DISABLED]      MgmtEth0/RP0/CPU0/0      120        B               gi19
MYS-130         MgmtEth0/RP0/CPU0/1      120        R               MgmtEth0/RP0/CPU0/1

where [ DISABLED] shows that the LLDP is disabled on the interface MgmtEth0/RP0/CPU0/0.

When you enable LLDP drop on the client controller ports of the muxponder or muxponder slice, the LLDP frames drop on the ports without forwarding.

Note
LLDP on 400GE is not supported on the OTN-XP card.