LDP Diagnostics

Note:

LDP treetrace works best with label-IP (lbl-ip) hashing enabled, rather than label-only (lbl-only) hashing. These options are set with the lsr-load-balancing command. For information on the lsr-load-balancing command, refer to the 7705 SAR Basic System Configuration Guide, ‟System Command Reference” and the 7705 SAR Router Configuration Guide, ‟IP Router Command Reference”.

ldp-treetrace

Syntax

ldp-treetrace prefix ip-prefix/mask [max-ttl max-label-ttl] [max-path max-paths] [timeout timeout] [retry-count retry-count] [fc fc-name [profile {in | out}]] [downstream-map-tlv {dsmap | ddmap}]

Context

oam

Description

This command configures LDP treetrace parameters in order to perform OAM manual treetrace tests on demand. Treetrace tests are used to discover all possible ECMP paths of an LSP.

Parameters

ip-prefix/mask

the address prefix and subnet mask of the destination node

max-label-ttl

the maximum time-to-live value in the MPLS label for the LSP trace test, expressed as a decimal integer

Values

1 to 255

Default

30

max-paths

the maximum number of paths for an LDP treetrace test

Values

1 to 255

Default

128

timeout

the maximum amount of time, in seconds, that the router will wait for a message reply after sending the message request. The timeout parameter overrides the default timeout value. If the timeout expires, the requesting router assumes that the message response will not be received. Any response received after the request times out will be silently discarded.

Values

1 to 60

Default

3

retry-count

the maximum number of consecutive MPLS echo requests that do not receive a reply before the trace operation fails for a given TTL

Values

1 to 225

Default

5

fc-name

the forwarding class of the MPLS echo request packets. The actual forwarding class encoding is controlled by the network egress LSP-EXP mappings.

The LSP-EXP mappings on the receive network interface control the mapping back to the internal forwarding class used by the far-end 7705 SAR that receives the message request. The egress mappings of the egress network interface on the far-end 7705 SAR control the forwarding class markings on the return reply message.

The LSP-EXP mappings on the receive network interface control the mapping of the message reply at the originating 7705 SAR.

Values

be, l2, af, l1, h2, ef, h1, nc

Default

be

profile {in | out}

the profile state of the MPLS echo request encapsulation

Default

out

downstream-map-tlv {dsmap | ddmap}

specifies which format of the downstream mapping TLV to use in the LSP trace packet. Use dsmap for the original target FEC stack TLV for BGP-labeled IPv4/32 prefixes as defined in RFC 4379 or ddmap for the enhanced TLV format specified in RFC 6424. If this parameter is not set, the value will be inherited from the global downstream mapping TLV value.

Default

inherited from the global configuration of the downstream mapping TLV in the mpls-echo-request-downstream-map command

ldp-treetrace

Syntax

[no] ldp-treetrace

Context

config>test-oam

Description

This command enables the context to configure LDP treetrace parameters in order to perform OAM manual treetrace tests. Treetrace commands at this level configure periodic proactive treetrace and set path discovery and path probing parameters.

fc

Syntax

fc fc-name [profile {in | out}]

no fc

Context

config>test-oam>ldp-treetrace

Description

This command configures forwarding class name and profile parameters. The parameters indicate the forwarding class of the MPLS echo request packets. The actual forwarding class encoding is controlled by the network egress LSP-EXP mappings. The LSP-EXP mappings on the receive network interface control the mapping back to the internal forwarding class used by the far-end 7705 SAR that receives the message request. The egress mappings of the egress network interface on the far-end 7705 SAR control the forwarding class markings on the return reply message.

The LSP-EXP mappings on the receive network interface control the mapping of the message reply at the originating 7705 SAR.

Parameters

fc-name

the forwarding class of the MPLS echo request packets.

Values

be, l2, af, l1, h2, ef, h1, nc

Default

be

profile {in | out}

the profile state of the MPLS echo request encapsulation

Default

out

path-discovery

Syntax

path-discovery

Context

config>test-oam>ldp-treetrace

Description

This command enables the context to configure path discovery parameters for ECMP paths of an LSP.

interval

Syntax

interval minutes

no interval

Context

config>test-oam>ldp-treetrace>path-discovery

Description

This command configures the time to wait before repeating the LDP tree auto-discovery process.

Default

60

Parameters

minutes

the number of minutes to wait before repeating the LDP tree auto-discovery process

Values

60 to 1440

max-path

Syntax

max-path max-paths

no max-path

Context

config>test-oam>ldp-treetrace>path-discovery

Description

This command configures the maximum number of paths that can be discovered for a selected IP address FEC.

Default

128

Parameters

max-paths

the maximum number of paths for the tree discovery

Values

1 to 128

max-ttl

Syntax

max-ttl ttl-value

no max-ttl

Context

config>test-oam>ldp-treetrace>path-discovery

Description

This command configures the maximum time-to-live value in the MPLS label for an LSP trace request during the tree discovery.

Default

30

Parameters

ttl-value

the maximum TTL value for an LSP trace request during the tree discovery

Values

1 to 255

policy-statement

Syntax

policy-statement policy-name [policy-name...(up to 5 max)]

no policy-statement

Context

config>test-oam>ldp-treetrace>path-discovery

Description

This command specifies policies to filter LDP imported address FECs.

Default

no policy-statement

Parameters

policy-name

the route policy name to filter LDP imported address FECs. Allowed values are any string up to 32 characters long composed of printable, 7-bit ASCII characters. If the string contains special characters (#, $, spaces, etc.), the entire string must be enclosed within double quotes. The specified policy names must already be defined.

retry-count

Syntax

retry-count retry-count

no retry-count

Context

config>test-oam>ldp-treetrace>path-discovery

Description

This command configures the maximum number of consecutive timeouts before the path probe fails.

Default

3

Parameters

retry-count

the maximum number of timeouts

Values

1 to 255

timeout

Syntax

timeout timeout

no timeout

Context

config>test-oam>ldp-treetrace>path-discovery

Description

This command configures the maximum amount of time, in seconds, that the router will wait for a message reply after sending the message request. The timeout command overrides the default timeout value. If the timeout expires, the requesting router assumes that the message response will not be received. Any response received after the request times out will be silently discarded.

Default

30

Parameters

timeout

the maximum amount of time that the router will wait for a message reply

Values

1 to 60

path-probing

Syntax

path-probing

Context

config>test-oam>ldp-treetrace

Description

This command enables the context to configure path probing parameters for ECMP paths of an LSP.

interval

Syntax

interval minutes

no interval

Context

config>test-oam>ldp-treetrace>path-probing

Description

This command configures the time to wait before repeating a probe (ping) on an ECMP-discovered path of an LSP.

Default

1

Parameters

minutes

the number of minutes to wait between probing ECMP paths

Values

1 to 60

retry-count

Syntax

retry-count retry-count

no retry-count

Context

config>test-oam>ldp-treetrace>path-probing

Description

This command configures the maximum number of consecutive timeouts before the path probe fails.

Default

3

Parameters

retry-count

the maximum number of timeouts

Values

1 to 255

timeout

Syntax

timeout timeout

no timeout

Context

config>test-oam>ldp-treetrace>path-probing

Description

This command configures the maximum amount of time, in seconds, that the router will wait for a message reply after sending the message request. The timeout command overrides the default timeout value. If the timeout expires, the requesting router assumes that the message response will not be received. Any response received after the request times out will be silently discarded.

Default

1

Parameters

timeout

the maximum amount of time that the router will wait for a message reply

Values

1 to 3