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ping mpls lsp-end-point



Check the operability of MPLS label-switched path (LSP) endpoint connections. Type Ctrl+c to interrupt a ping mpls command.


count count

(Optional) Number of ping requests to send. If count is not specified, five ping requests are sent. The range of values is 1 through 1,000,000. The default value is 5.

destination address

(Optional) Specify an address other than the default ( for the ping echo requests. The address can be anything within the 127/8 subnet.


(Optional) Display detailed information about the echo requests sent and received.

exp forwarding-class

(Optional) Value of the forwarding class for the MPLS ping packets.

instance routing-instance-name

(Optional) Ping a combination of the routing instance and forwarding equivalence class (FEC) associated with an LSP connection.

logical-system (all | logical-system-name)

(Optional) Perform this operation on all logical systems or on the specified logical system.


LDP forwarding equivalence class (FEC) prefix or RSVP LSP endpoint address.

size bytes

(Optional) Size of the LSP ping request packet. If the endpoint is LDP-based, the minimum size of the packet is 88 bytes. If the endpoint is RSVP-based, the minimum size of the packet is 100 bytes. The maximum size in either case is 65468 bytes.

source source-address

(Optional) IP address of the outgoing interface. This address is sent in the IP source address field of the ping request. If this option is not specified, the default address is usually the loopback interface (lo.0).


(Optional) Automatically determine the size of the maximum transmission unit (MTU).

Additional Information

If the LSP changes, the label and interface information displayed when you issued the ping command continues to be used. You must configure MPLS at the [edit protocols mpls] hierarchy level on the remote router or switch to ping an LSP terminating there. You must configure MPLS even if you intend to ping only LDP forwarding equivalence classes (FECs).

In asymmetric MTU scenarios, the echo response might be dropped. For example, if the MTU from System A to System B is 1000 bytes, the MTU from System B to System A is 500 bytes, and the ping request packet size is 1000 bytes, the echo response is dropped because the PAD TLV is included in the echo response, making it too large.


In a Juniper-Cisco interoperation network scenario, a point-to-multipoint LSP ping echo reply message from a Cisco device in a different IGP area is dropped on the Juniper device when the source address of the reply message is an interface address other than the loopback address or router ID. Starting in Junos OS Release 13.3X8, 14.2R6, 15.1R4, 15.1F6, 15.1F5-S8, 16.1R1, and later releases, such point-to-multipoint LSP ping echo reply messages are accepted by the Juniper device and the messages get logged as uncorrelated responses.

Required Privilege Level


Output Fields

When you enter this command, you are provided feedback on the status of your request. An exclamation point (!) indicates that an echo reply was received. A period (.) indicates that an echo reply was not received within the timeout period. An x indicates that an echo reply was received with an error code. Packets with an error code are not counted in the received packets count. They are accounted for separately.

Sample Output

ping mpls lsp-end-point detail

Release Information

Command introduced before Junos OS Release 7.4.

The size and sweep options were introduced in Junos OS Release 9.6.

The instance option was introduced in Junos OS Release 10.0.