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traceroute mpls ldp

Syntax

traceroute mpls <ldp> fec<destination><detail><exp><fanout><logical-system><no-resolve><paths><retries><routing-instance><source><ttl><update><wait>

Release Information

Command introduced in Junos OS Release 8.4.

Description

Trace route to a remote host for an MPLS label-switched path signaled by the LDP. Use traceroute mpls ldp as a debugging tool to locate MPLS label-switched path forwarding issues in a network. (Currently supported for IPv4 packets only.)

Options

fec

Specify the IP address and optional prefix of the forwarding equivalence class (FEC).

destination

(Optional) Specify the destination address to use when sending probes.

detail

(Optional) Display detailed output.

exp

(Optional) Specify the class-of-service to use when sending probes. The range of values is 0 through 7. The default value is 7.

fanout

(Optional) Specify the maximum number of nexthops to search per node. The range of values is 1 through 16. The default value is 16.

logical-system

(Optional) Specify the name of the logical system for the traceroute attempt.

no-resolve

(Optional) Specify not to resolve the hostname that corresponds to the IP address.

paths

(Optional) Specify the number of paths to search. The range of values is 1 through 255. The default value is 16.

retries

(Optional) Specify the number of times to resend probe. values. The range of values is 1 through 9. The default value is 3.

routing-instance routing-instance-name

(Optional) Specify the name of the routing instance for the traceroute attempt.

source source-address

(Optional) Specify the source address of the outgoing traceroute packets.

ttl value

(Optional) Specify the maximum time-to-live value to include in the traceroute request, in seconds. The range of values is 1 through 125 and the default value is 64.

wait seconds

(Optional) Specify the number of seconds to wait before resending a probe. The range of values is 5 through 15 and the default value is 10 seconds.

Required Privilege Level

network

List of Sample Output

traceroute mpls ldp
traceroute mpls ldp detail

Output Fields

Table 1 describes the output fields for the traceroute mpls ldp fec command and the traceroute mpls ldp fec detail commands. Output fields are listed in the approximate order in which they appear.

Table 1: traceroute mpls ldp Output Fields

Field Name

Field Description

Level of Output

Probe options

Probe options specified in the traceroute mpls ldp fec command.

all levels

ttl

Time to live value of the labeled packet.

none specified

Label

Outgoing label used for forwarding the packet along the label-switched paths.

none specified

Protocol

Signaling protocol used. For this command, it is LDP.

none specified

Address

Address of the next hop.

none specified

Previous Hop

Address of the previous hop. Previous hop address of the first hop is null.

none specified

Probe status

Forwarding status from the first hop to the last-hop label-switching router (egress point in the label-switched paths).

none specified

Hop

Address of the hops in the label-switched path from the first hop to the last hop. Depth indicates the level of the hop.

detail

Parent

Address of the previous hop. Parent value for the first hop is null.

detail

Return Code

Return code for reporting the result of processing the echo request by the receiver.

detail

Response time

Time for the echo request to reach the receiver.

detail

Multipath type

Labels or addresses used by the specified multipath type. If multipaths are not used, the value is none.

detail

Label Stack

Label stack used to forward the packet.

detail

Sample Output

traceroute mpls ldp

user@router> traceroute mpls ldp 4.4.4.4
  Probe options: ttl 64, retries 3, wait 10, paths 16, exp 7, fanout 16
  ttl    Label  Protocol    Address          Previous Hop     Probe Status
    1   100016  LDP         24.24.24.1       (null)           Success
    2   100000  LDP         20.20.20.2       24.24.24.1       Success
    3        3  LDP         22.22.22.4       20.20.20.2       Egress

Path 1 via fe-0/3/3.101 destination 127.0.0.64

traceroute mpls ldp detail

user@router> traceroute mpls ldp 4.4.4.4 detail
  Probe Options: ttl 64, retries 3, wait 10, paths 3, exp 7
  Hop 24.24.24.1 Depth 1
    Parent (null)
    Return code: Label switched at stack-depth 1
    Response time 165.93 msec
    Multipath type: IP bitmask
      Address Range 1: 127.0.0.0 ~ 127.0.3.255
    Label Stack:
      Label 1 Value 100032 Protocol LDP

  Hop 20.20.20.2 Depth 2
    Parent 24.24.24.1
    Return code: Upstream interface index unknown label-switched at stack-depth 1
    Response time 19.05 msec
    Multipath type: IP bitmask
      Address Range 1: 127.0.0.0 ~ 127.0.3.255
    Label Stack:
      Label 1 Value 100000 Protocol LDP

  Hop 22.22.22.4 Depth 3
    Parent 20.20.20.2
    Return code: Egress-ok at stack-depth 1
    Response time 0.79 msec
    Multipath type: None
    Label Stack:
      Label 1 Value 3 Protocol LDP

Published: 2013-07-09

Published: 2013-07-09