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MPLS LDP Autoconfiguration

Table Of Contents

MPLS LDP Autoconfiguration

Contents

Information About MPLS LDP Autoconfiguration

How to Configure MPLS LDP Autoconfiguration

Configuring MPLS LDP Autoconfiguration

Prerequisites

Restrictions

Selectively Disabling MPLS LDP Autoconfiguration from Some Interfaces

Verifying MPLS LDP Autoconfiguration

Troubleshooting Tips

Configuration Examples for MPLS LDP Autoconfiguration

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Command Reference

debug mpls ldp autoconfig

mpls ldp autoconfig

mpls ldp igp autoconfig

show mpls interfaces

show mpls ldp discovery


MPLS LDP Autoconfiguration

The Multiprotocol Label Switching (MPLS) Label Distribution Protocol (LDP) Autoconfiguration feature enables you to globally configure LDP on every interface associated with a specified Interior Gateway Protocol (IGP) instance.

Feature History for the MPLS LDP Autoconfiguration Feature

Release
Modification

12.0(30)S

This feature was introduced.

12.3(14)T

This feature was integrated into Cisco IOS Release 12.3(14)T.

12.2(27)SBA

This feature was integrated into Cisco IOS Release 12.2(27)SBA.


Finding Support Information for Platforms and Cisco IOS Software Images

Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.

Contents

•Information About MPLS LDP Autoconfiguration

•How to Configure MPLS LDP Autoconfiguration

•Configuration Examples for MPLS LDP Autoconfiguration

•Additional References

•Command Reference

Information About MPLS LDP Autoconfiguration

To enable LDP, you must configure it globally, as well as on each interface where it is needed. Configuring LDP on many interfaces can be time consuming.

MPLS LDP Autoconfiguration enables you to globally enable LDP on every interface associated with an IGP instance. Currently, the only IGP that supports this feature is Open Shortest Path First (OSPF). Further, it provides a means to block LDP from being enabled on interfaces that you do not want enabled. The goal of MPLS LDP Autoconfiguration is to make configuration easier, faster, and error free.

You issue the mpls ldp autoconfig command to enable LDP on each interface that belongs to an OSPF area. If you do not want some of the interfaces to have LDP enabled, you can issue the no form of the mpls ldp igp autoconfig command on those interfaces.

How to Configure MPLS LDP Autoconfiguration

This section explains how to configure and verify MPLS LDP Autoconfiguration:

•Configuring MPLS LDP Autoconfiguration (required)

•Selectively Disabling MPLS LDP Autoconfiguration from Some Interfaces (optional)

•Verifying MPLS LDP Autoconfiguration (optional)

Configuring MPLS LDP Autoconfiguration

Prerequisites

•You must issue the global mpls ip command before issuing the mpls ldp autoconfig command.

Restrictions

This feature is not supported under the following circumstances:

•If LDP is disabled globally, the mpls ldp autoconfig command fails and generates a console message explaining that LDP must be enabled globally by means of the global mpls ip command first.

•If the mpls ldp autoconfig command is configured for an IGP instance, you cannot issue the global no mpls ip command. If you want to disable LDP, you must issue the no mpls ldp autoconfig command first.

•The mpls ldp autoconfig command is supported only with OSPF. Other IGPs are not supported.

•If LDP is enabled on an interface by the mpls ldp autoconfig command, you cannot use the interface-level no mpls ip command to disable LDP on the interface. LDP can be disabled on the interface by using the no mpls ldp igp autoconfig command.

•You specify that the default label distribution protocol is LDP for a router or for an interface. Tag Distribution Protocol (TDP) is not supported.

•MPLS LDP Autoconfiguration is not supported on Traffic Engineering tunnel interfaces.

SUMMARY STEPS

1. enable

2. configure terminal

3. mpls ip

4. mpls label protocol ldp

5. interface interface

6. ip address {prefix mask}

7. router ospf process-id

8. network ip-address wildcard-mask area area-id

9. mpls ldp autoconfig [area area-id]

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

mpls ip

Example:

Router(config)# mpls ip

Globally enables hop-by-hop forwarding.

Step 4 

mpls label protocol ldp

Example:

Router(config)# mpls label protocol ldp

Specifies LDP as the default label distribution protocol.

Step 5 

interface interface

Example:

Router(config)# interface POS3/0

Specifies the interface to configure and enters interface configuration mode.

Step 6 

ip address {prefix mask}

Example:

Router(config-if)# ip address 133.0.0.11 255.255.255.255

Assigns an IP address to the interface.

Step 7 

router ospf process-id

Example:

Router(config)# router ospf 1

Enables OSPF routing and enters router configuration mode.

Step 8 

network ip-address wildcard-mask area area-id

Example:

Router(config-router)# network 133.0.0.0 0.0.255.255 area 3

Defines an interface on which OSPF runs and defines the area ID for that interface.

Step 9 

mpls ldp autoconfig [area area-id]

Example:

Router(config-router)# mpls ldp autoconfig area 3

Enables MPLS LDP Autoconfiguration for interfaces belonging to an OSPF process. If no area is specified, the command applies to all interfaces associated with the OSPF process. If an area ID is specified, then only interfaces associated with that OSPF area are enabled with LDP Autoconfiguration.

Selectively Disabling MPLS LDP Autoconfiguration from Some Interfaces

When you issue the mpls ldp autoconfig command, all the interfaces that belong to an OSPF area are enabled for LDP. If you want to remove LDP from some interfaces, you can use the no mpls ldp igp autoconfig command on those interfaces. The following configuration steps show how to disable LDP from some of the interfaces after they were configured with LDP through the mpls ldp autoconfig command.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface interface

4. no mpls ldp igp autoconfig

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface interface

Example:

Router(config)# interface POS3/0

Specifies the interface to configure and enters interface configuration mode.

Step 4 

no mpls ldp igp autoconfig

Example:

Router(config-if)# no mpls ldp igp autoconfig

Disables LDP for that interface.

Verifying MPLS LDP Autoconfiguration

Two commands display information about MPLS LDP Autoconfiguration.

The show mpls ldp discovery and show mpls interfaces commands list the method that was used to enable LDP on an interface.

•If LDP is enabled by the mpls ldp autoconfig command, the output displays: 

IP labeling enabled (ldp):

   IGP config

•If LDP is enabled by the mpls ip command, the output displays: 

IP labeling enabled (ldp):

  Interface config

•If LDP is enabled by the mpls ip command and the mpls ldp autoconfig command, the output displays: 

IP labeling enabled (ldp):

  Interface config

  IGP config

The following examples show that LDP was enabled on the interface by both the mpls ip and mpls ldp autoconfig commands: 

Router# show mpls ldp discovery detail


Local LDP Identifier:

    11.11.11.11:0

    Discovery Sources:

    Interfaces:

        Serial2/0 (ldp): xmit/recv

            Enabled: Interface config, IGP config;

            Hello interval: 5000 ms; Transport IP addr: 11.11.11.11 

            LDP Id: 10.10.10.10:0

              Src IP addr: 140.0.0.1; Transport IP addr: 10.10.10.10

              Hold time: 15 sec; Proposed local/peer: 15/15 sec


Router# show mpls interfaces S2/0 detail 


Interface Serial2/0:

        IP labeling enabled (ldp):

          Interface config

          IGP config

        LSP Tunnel labeling enabled

        BGP labeling not enabled

        MPLS operational

        Fast Switching Vectors:

          IP to MPLS Fast Switching Vector

          MPLS Turbo Vector

        MTU = 1500

Troubleshooting Tips

You can use the debug mpls ldp autoconfig command to display events related to MPLS LDP Autoconfiguration.

Configuration Examples for MPLS LDP Autoconfiguration

The following configuration commands enable LDP for OSPF process 1 area 3. The mpls ldp autoconfig area 3 command and the OSPF network commands enable LDP on interfaces POS0/0, POS0/1, and POS1/1. The no mpls ldp igp autoconfig command on interface po1/0 prevents LDP from being enabled on interface po1/0, even though OSPF is enabled for that interface. 

Router# config terminal

Router(config)# interface POS0/0

Router(config-if)# ip address 133.0.0.1

  ...

Router(config)# interface POS0/1

Router(config-if)# ip address 133.0.1.1

  ...

Router(config)# interface POS1/1

Router(config-if)# ip address 133.1.1.1

  ...

Router(config)# interface POS1/0

Router(config-if)# ip address 133.1.0.1

  ...

Router(config)# router ospf 1

Router(config-router)# ...

Router(config-router)# network 133.0.0.0 0.0.255.255 area 3

Router(config-router)# network 133.1.0.0 0.0.255.255 area 3

Router(config-router)# mpls ldp autoconfig area 3

Router(config-router)# exit

Router(config)# interface POS1/0

Router(config-if)# no mpls ldp igp autoconfig

Router(config-if)# ...

Additional References

The following sections provide references related to MPLS LDP Autoconfiguration.

Related Documents

Related Topic
Document Title

MPLS LDP

MPLS Label Distribution Protocol

MPLS LDP-IGP Synchronization

MPLS LDP-IGP Synchronization

MPLS LDP Session Protection

MPLS LDP Session Protection


Standards

Standard
Title

None

—


MIBs

MIB
MIBs Link

•MPLS LDP MIB

To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs


RFCs

RFC
Title

RFC 3036

LDP Specification

RFC 3037

LDP Applicability


Technical Assistance

Description
Link

The Cisco Technical Support website contains thousands of pages of searchable technical content, including links to products, technologies, solutions, technical tips, and tools. Registered Cisco.com users can log in from this page to access even more content.

http://www.cisco.com/techsupport


Command Reference

This section documents new and modified commands. All other commands are documented in Cisco IOS Release 12.3 Command Reference.

New commands

•debug mpls ldp autoconfig

•mpls ldp autoconfig

•mpls ldp igp autoconfig

Modified commands

•show mpls interfaces

•show mpls ldp discovery

debug mpls ldp autoconfig

To enable the display of events related to Multiprotocol Label Switching (MPLS) Label Distribution Protocol (LDP), use the debug mpls ldp autoconfig command in privileged EXEC mode. To disable this feature, use the no form of this command.

debug mpls ldp autoconfig [interface interface]

no debug mpls ldp autoconfig [interface interface]

Syntax Description

interface interface

(Optional) Enables the display of autoconfiguration events for the specified interface.


Defaults

None

Command Modes

Privileged EXEC

Command History

Release
Modification

12.0(30)S

This command was introduced.

12.3(14)T

This command was integrated into Cisco IOS Release 12.3(14)T.

12.2(27)SBA

This command was integrated into Cisco IOS Release 12.2(27)SBA.


Examples

In the following example, the display of events related to MPLS LDP Autoconfiguration are enabled: 

Router# debug mpls ldp autoconfig 


00:06:06: LDP-AC: OSPF area 1 [flags 0x8, handle 0x1030110]:: Adding record 

00:06:06: LDP-AC: OSPF area 1 [flags 0x8, handle 0x1030110]:: Received

enable request for Serial2/0

00:06:06: LDP-AC: OSPF area 1 [flags 0xA, handle 0x1030110]:: Adding record

to Serial2/0

00:06:06: LDP-AC: OSPF area 1 [flags 0xA, handle 0x1030110]:: Enqueued LDP

enable request on Serial2/0

00:06:06: LDP-AC: OSPF area 1 [flags 0x8, handle 0x1030110]:: Received

enable request for Tunnel1

00:06:06: LDP-AC: OSPF area 1 [flags 0xA, handle 0x1030110]:: Adding record

to Tunnel1

00:06:06: LDP-AC: OSPF area 1 [flags 0xA, handle 0x1030110]:: Enqueued LDP

enable request on Tunnel1

00:06:06: LDP-AC: Enabling LDP on interface Serial2/0

00:06:06: LDP-AC: Enabling LDP on interface Tunnel1

Related Commands

Command
Description

mpls ldp autoconfig

Enables LDP on all interfaces that belong to an OSPF area.

show mpls ldp discovery

Displays information about interfaces configured for LDP.


mpls ldp autoconfig

To enable Label Distribution Protocol (LDP) on interfaces for which an Open Shortest Path First (OSPF) instance has been defined, use the mpls ldp autoconfig command in router configuration mode. To disable this feature, use the no form of this command.

mpls ldp autoconfig [area area-id]

no mpls ldp autoconfig [area area-id]

Syntax Description

area area-id

(Optional) Enables LDP on the interfaces belonging to the specified OSPF area.


Defaults

LDP is not enabled on interfaces. If an OSPF area is not specified, LDP is enabled on all interfaces belonging to the OSPF process.

Command Modes

Router configuration

Command History

Release
Modification

12.0(30)S

This command was introduced.

12.3(14)T

This command was integrated into Cisco IOS Release 12.3(14)T.

12.2(27)SBA

This command was integrated into Cisco IOS Release 12.2(27)SBA.


Usage Guidelines

•You can specify this command multiple times to enable LDP on different routing areas.

•If LDP is disabled globally, the mpls ldp autoconfig command fails. LDP must be enabled globally by means of the global mpls ip command first.

•If the mpls ldp autoconfig command is configured, you cannot issue the global no mpls ip command. If you want to disable LDP, you must issue the no mpls ldp autoconfig command first.

•The mpls ldp autoconfig command is supported only with OSPF. Other IGPs are not supported.

•If LDP is enabled on an interface by the mpls ldp autoconfig command, you cannot use the interface-level no mpls ip command to disable LDP on the interface. LDP can be disabled on the interface by using the no mpls ldp igp autoconfig command.

Examples

In the following example, MPLS LDP Autoconfiguration is enabled for OSPF area 5: 

Router(config-router)# mpls ldp autoconfig area 5

Related Commands

Command
Description

mpls ldp igp autoconfig

Enables or disables LDP on an interface.

show mpls interfaces

Displays information about interfaces configured for LDP.

show mpls ldp discovery

Displays the status of the LDP discovery process.


mpls ldp igp autoconfig

To disable LDP on an interface that belongs to an OSPF area, use the no mpls ldp igp autoconfig command in interface configuration mode. (See the Usage Guidelines for more information.)

mpls ldp igp autoconfig

no mpls ldp igp autoconfig

Syntax Description

This command has no arguments or keywords.

Defaults

This command works with the mpls ldp autoconfig command, which enables LDP on all interfaces that belong to an OSPF area. So, by default, all interfaces are enabled for LDP.

Command Modes

Interface configuration

Command History

Release
Modification

12.0(30)S

This command was introduced.

12.3(14)T

This command was integrated into Cisco IOS Release 12.3(14)T.

12.2(27)SBA

This command was integrated into Cisco IOS Release 12.2(27)SBA.


Usage Guidelines

This command works with the mpls ldp autoconfig command, which enables LDP on all interfaces that belong to an OSPF area. To disable LDP on selected interfaces, use the no mpls ldp igp autoconfig command.

Examples

In the following example, LDP is disabled on interface POS1/0: 

Router(config)# interface pos1/0

Router(config-if)# no mpls ldp igp autoconfig

Related Commands

Command
Description

mpls ldp autoconfig

Globally enables LDP on all interfaces that belong to an OSPF area.

show mpls interfaces

Displays information about interfaces configured for LDP.

show mpls ldp discovery

Displays the status of the LDP discovery process.


show mpls interfaces

To display information about one or more or all interfaces that are configured for label switching, use the show mpls interfaces command in privileged EXEC mode.

show mpls interfaces [vrf vpn-name] [interface] [detail]

show mpls interfaces [all]

Syntax Description

vrf vpn-name

(Optional) Displays information about the interfaces that have been configured for label switching for the specified Virtual Private Network (VPN) routing/forwarding instance (vpn-name).

interface

(Optional) Defines the interface about which to display label switching information.

detail

(Optional) Displays detailed label switching information for the specified interface.

all

(Optional) When the all keyword is specified alone in this command, information about the interfaces configured for label switching is displayed for all VPNs, including the VPNs in the default routing domain.


Defaults

If no optional keyword or argument is specified in this command, summary information is displayed for each interface that has been configured for label switching in the default routing domain.

Command Modes

Privileged EXEC

Command History

Release
Modification

11.1CT

This command was introduced.

12.0(10)ST

This command was modified to reflect MPLS IETF command syntax and terminology.

12.0(14)ST

This command was updated with the vrf and all keywords to reflect MPLS VPN support for LDP.

12.1(2)T

This command was integrated into Cisco IOS Release 12.1(2)T.

12.1(8a)E

This command was integrated into Cisco IOS Release 12.1(8a)E.

12.0(22)S

This command was integrated into Cisco IOS Release 12.0(22)S.

12.2(14)S

This command was integrated into Cisco IOS Release 12.2(14)S.

12.0(30)S

This command was updated to display information related to MPLS LDP Autoconfiguration.

12.3(14)T

This command was integrated into Cisco IOS Release 12.3(14)T.

12.2(27)SBA

This command was integrated into Cisco IOS Release 12.2(27)SBA.


Usage Guidelines

This command shows MPLS information about the specified interface, or about all the interfaces for which MPLS has been configured.

Examples

The following shows sample output generated by the show mpls interfaces command: 

Router# show mpls interfaces


Interface              IP         Tunnel   Operational

Ethernet1/1/1          Yes (tdp)  No       No          

Ethernet1/1/2          Yes (tdp)  Yes      No          

Ethernet1/1/3          Yes (tdp)  Yes      Yes         

POS2/0/0               Yes (tdp)  No       No          

ATM0/0.1               Yes (tdp)  No       No          (ATM labels)

ATM3/0.1               Yes (ldp)  No       Yes         (ATM labels)

ATM0/0.2               Yes (tdp)  No       Yes

Note If an interface uses LC-ATM procedures, the associated line in the display is flagged with the notation (ATM labels).

Table 1 describes the significant fields shown in the display.

Table 1 show mpls interfaces Field Descriptions 

Field
Description

Interface

Interface name.

IP

"Yes" if IP label switching (sometimes called hop-by-hop label switching) has been enabled on this interface.

Tunnel

"Yes" if LSP tunnel labeling has been enabled on this interface.

Operational

Operational state. "Yes" if labeled packets can be sent over this interface. Labeled packets can be sent over an interface if an MPLS protocol is configured on the interface and required Layer 2 negotiations have occurred.


The following is sample output from the show mpls interfaces command when you specify the detail keyword. The output shows that interface serial 2/0 has LDP enabled by both the mpls ip command and the mpls ldp autoconfig command. 

Router# show mpls interfaces S2/0 detail 


Interface Serial2/0:

        IP labeling enabled (ldp):

          Interface config

          IGP config

        LSP Tunnel labeling enabled

        BGP labeling not enabled

        MPLS operational

        Fast Switching Vectors:

          IP to MPLS Fast Switching Vector

          MPLS Turbo Vector

        MTU = 1500

•If LDP is enabled by the mpls ldp autoconfig command, the output displays: 

IP labeling enabled (ldp):

   IGP config

•If LDP is enabled by the mpls ip command, the output displays: 

IP labeling enabled (ldp):

  Interface config

•If LDP is enabled by the mpls ip command and the mpls ldp autoconfig command, the output displays: 

IP labeling enabled (ldp):

  Interface config

  IGP config

Related Commands

Command
Description

debug mpls ldp autoconfig

Displays events related to MPLS LDP Autoconfiguration.

show mpls ldp discovery

Displays information about interfaces enabled for LDP.


show mpls ldp discovery

To display the status of the label distribution protocol (LDP) discovery process, use the show mpls ldp discovery command in privileged EXEC mode. This command generates a list of interfaces over which the LDP discovery process is running.

show mpls ldp discovery [all | detail | vrf vpn-name]

Syntax Description

all

(Optional) When the all keyword is specified alone in this command, the command displays LDP discovery information for all VPNs, including those in the default routing domain.

detail

Displays detailed LDP discovery information.

vrf vpn-name

(Optional) Displays the neighbor discovery information for the specified VPN routing/forwarding instance (vpn-name).


Defaults

This command displays neighbor discovery information for the default routing domain if an optional argument is not specified.

Command Modes

Privileged EXEC

Command History

Release
Modification

11.1CT

This command was introduced.

12.0(10)ST

This command was modified to reflect MPLS IETF command syntax and terminology.

12.0(14)ST

This command was updated with the vrf and all keywords to reflect MPLS VPN support for LDP.

12.1(2)T

This command was integrated into Cisco IOS Release 12.1(2)T.

12.1(8a)E

This command was integrated into Cisco IOS Release 12.1(8a)E.

12.0(21)ST

This command was integrated into Cisco IOS Release 12.0(21)ST.

12.0(22)S

This command was integrated into Cisco IOS Release 12.0(22)S.

12.2(14)S

This command was integrated into Cisco IOS Release 12.2(14)S.

12.0(30)S

This command was updated to display information related to LDP Autoconfiguration.

12.3(14)T

This command was integrated into Cisco IOS Release 12.3(14)T.

12.2(27)SBA

This command was integrated into Cisco IOS Release 12.2(27)SBA.


Usage Guidelines

This command displays neighbor discovery information for LDP or Tag Distribution Protocol (TDP).

Examples

The following shows sample output from the show mpls ldp discovery command: 

Router# show mpls ldp discovery


Local LDP Identifier:

    8.1.1.1:0

Discovery Sources:

    Interfaces:

        Ethernet1/1/3 (ldp): xmit/recv

            LDP Id: 177.73.0.77:0

            LDP Id: 144.0.0.44:0

            LDP Id: 155.0.0.55:0

        ATM3/0.1 (ldp): xmit/recv

            LDP Id: 203.0.7.7:2

        ATM0/0.2 (tdp): xmit/recv

            TDP Id: 119.1.0.1:1

Targeted Hellos:

        8.1.1.1 -> 133.0.0.33 (ldp): active, xmit/recv

            LDP Id: 133.0.0.33:0

        8.1.1.1 -> 168.7.0.16 (tdp): passive, xmit/recv

            TDP Id: 133.0.0.33:0

The following shows sample output from the show mpls ldp discovery all command, which shows the interfaces engaged in LDP discovery activity for all the VPN routing/forwarding instances, including those in the default routing domain. In this example, note that the same neighbor LDP ID (14.14.14.14) appears in all the listed VRF interfaces, highlighting the fact that the same IP address can coexist in different VPN routing/forwarding instances. 

Router# show mpls ldp discovery all 


Local LDP Identifier:

    12.12.12.12:0

    Discovery Sources:

    Interfaces:

        ATM1/1/0.1 (tdp):xmit/recv

            TDP Id:11.11.11.11:0

VRF vpn1:Local LDP Identifier:

    30.7.0.2:0

    Discovery Sources:

    Interfaces:

        ATM3/0/0.1 (ldp):xmit/recv

            LDP Id:14.14.14.14:0

VRF vpn2:Local LDP Identifier:

    30.13.0.2:0

    Discovery Sources:

    Interfaces:

        ATM3/0/0.2 (ldp):xmit/recv

            LDP Id:14.14.14.14:0

VRF vpn3:Local LDP Identifier:

    30.15.0.2:0

    Discovery Sources:

    Interfaces:

        ATM3/0/0.3 (ldp):xmit/recv

            LDP Id:14.14.14.14:0

VRF vpn4:Local LDP Identifier:

    30.17.0.2:0

    Discovery Sources:

    Interfaces:

        ATM3/0/0.4 (ldp):xmit/recv

            LDP Id:14.14.14.14:0

Table 2 describes the significant fields shown in the display.

Table 2 show mpls ldp discovery Field Descriptions 

Field
Description

Local LDP Identifier

The LDP identifier for the local router. An LDP identifier is a 6-byte construct displayed in the form "IP address:number."

By convention, the first four bytes of the LDP identifier constitute the router ID; integers, starting with 0, constitute the final two bytes of the IP address:number construct.

Interfaces

Lists the interfaces that are engaging in LDP discovery activity, described below:

•The xmit field—Indicates that the interface is transmitting LDP discovery Hello packets.

•The recv field—Indicates that the interface is receiving LDP discovery Hello packets.

•The (ldp) or (tdp) field—Indicates the label distribution protocol configured for the interface.

The LDP (or TDP) identifiers indicate the LDP (or TDP) neighbors discovered on the interface.

Targeted Hellos

Lists the platforms to which targeted Hello messages are being sent, as described below:

•The xmit, recv, (ldp), and (tdp) fields are as described above for the Interfaces field.

•The active field indicates that this LSR has initiated targeted Hello messages.

•The passive field indicates that the neighbor LSR has initiated targeted Hello messages and that this LSR is configured to respond to the targeted Hello messages from the neighbor.

Note The entry for a given target platform may indicate both active and passive.


The following shows sample output from the show mpls ldp discovery detail command, which displays the information related to LDP Autoconfiguration: 

Router# show mpls ldp discovery detail


Local LDP Identifier:

    11.11.11.11:0

    Discovery Sources:

    Interfaces:

        Serial2/0 (ldp): xmit/recv

            Enabled: Interface config, IGP config;

            Hello interval: 5000 ms; Transport IP addr: 11.11.11.11 

            LDP Id: 10.10.10.10:0

              Src IP addr: 140.0.0.1; Transport IP addr: 10.10.10.10

              Hold time: 15 sec; Proposed local/peer: 15/15 sec

•If LDP is enabled by the mpls ldp autoconfig command, the output displays: 

Enabled: IGP config;

•If LDP is enabled by the mpls ip command, the output displays: 

Enabled: Interface config;

•If LDP is enabled by the mpls ip command and the mpls ldp autoconfig command, the output displays: 

Enabled: Interface config; IGP config;

Related Commands

Command
Description

debug mpls ldp autoconfig

Displays events related to MPLS LDP Autoconfiguration.

show mpls interfaces

Displays information about one or more interfaces that have been configured for label switching.


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