ping mpls ldp

Syntax

Release Information

Command introduced before JUNOS Release 7.4.

The size and sweep options were introduced in JUNOS Release 9.6.

Description

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

Options

fec — (Optional) Ping an LDP-signaled LSP using the forwarding equivalence class (FEC) prefix and length.

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 (127.0.0.1/32) for the ping echo requests. The address can be anything within the 127/8 subnet.

detail — (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.

logical-system (all | logical-system-name) — (Optional) Perform this operation on all logical systems or on the specified logical system.

size bytes — (Optional) Size of the LSP ping request packet (88 through 65468 bytes). Packets are 4-byte aligned. For example, If you enter a size of 89, 90, 91, or 92, the router uses a size value of 92 bytes. If you enter a packet size that is smaller than the minimum size, an error message is displayed reminding you of the 88-byte minimum.

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).

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

Additional Information

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

You can configure the ping interval for the ping mpls ldp command by specifying a new time in seconds using the lsp-ping-interval statement at the [edit protocols ldp oam] hierarchy level. For more information, see the JUNOS MPLS Applications Configuration Guide.

In asymmetric MTU scenarios, the echo response may 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.

Required Privilege Level

network

List of Sample Output

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 error codes are not counted in the received packets count. They are accounted for separately.

Sample Output

!!!xxx...x--- lsping statistics ---10 packets transmitted, 3 packets received, 70% packet loss 4 packets received with error status, not counted as received.