Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

Guide That Contains This Content
[+] Expand All
[-] Collapse All

    trace mpls l2transport


    trace mpls l2transport [ vrf vrfName ]
    { interfaceType interfaceSpecifier }
    [ data-size dataSize ]
    [ destination startIpAddress endIpAddress increment ]
    [ source address sourceAddr ]
    [ ttl ttlValue ] [ timeout timeOutVal ]
    [ reply mode { ipv4-udp | ipv4-udp-with-router-alert } ]
    [ reply pad-tlv ] [ reply dscp trafficClass ]
    [ exp-bits bitValue ] [ bottom-label-ttl bottomLabelTtl ] [ detail ]

    Release Information

    Command introduced in JunosE Release 8.0.0.

    data-size keyword and dataSize variable added in JunosE Release 11.1.0.


    Sends MPLS echo request packets with successively higher TTL values to the specified layer 2 cross-connect virtual (Martini) circuit. Discovers the path MPLS packets follow to the destination. There is no no version.

    The echo request packet generated by this command contains the FEC 128 Pseudowire (Current) sub-TLV described in RFC 4379—Detecting Multi-Protocol Label Switched (MPLS) Data Plane Failures (February 2006).

    Note: This command is not supported for local cross-connects because local cross-connects do not employ an LSP.


    • vrfName—Name of the VRF context
    • interfaceType—Interface type; see Interface Types and Specifiers
    • interfaceSpecifier—Particular interface; format varies according to interface type; see Interface Types and Specifiers
    • dataSize—Size of the LSP ping message (does not include the UDP, IP, and MPLS headers of the packet); in the range 0–6400 bytes. The default value is 100 bytes.
    • startIpAddress—First IP address within the destination range
    • endIpAddress—Last IP address within the destination range
    • increment—Number in the range 0–255 that specifies the increment between addresses in the destination address range
    • sourceAddr—IP address used as the packet source address
    • ttlValue—Hop count specified by setting the time-to-live field in the header, in the range 1–255; default value is 32; however, by default, the TTL on the inner (stacked) label is set to 1 while transmitting the echo request packet, which causes the packet to be exceptioned to the SRP module when the stacked label is exposed
    • timeOutVal—Number of seconds in the range 1–32 to wait for an MPLS echo reply packet before the connection attempt times out
    • reply mode—Specifies the reply mode for the echo request packet
      • ipv4-udp—Specifies that the echo request packet is an IPv4 UDP packet
      • ipv4-udp-with-router-alert—Specifies that the echo request packet is an IPv4 UDP packet with the router alert bit set in the header so all routers examine this packet more closely to determine whether further processing is necessary
    • reply pad-tlv—Requests sender of an echo reply to send a pad TLV
    • trafficClass—Number in the range 0–255 that represents the value of the traffic class that the sender of an echo reply is requested to set
    • bitValue—Value of the EXP bits in the range 0–7 included in the MPLS echo request packet
    • bottomLabelTtl—Time-to-live value of the bottom label in the stack
    • detail—Displays detailed information about MPLS echo request sent and echo replies received


    Privileged Exec, User Exec

    Published: 2014-08-18