ping mpls lsp

ping mpls lsp [lsp_name | any host | prefix ipNetmask] {reply-mode [ip | ip-router-alert]} {continuous | count count} {interval interval} {start-size start-size {end-size end-size}} {ttl ttl} {{from from} {next-hop hopaddress}}

Description

Sends an MPLS ping packet to a FEC over an LSP.

Syntax Description

lsp_name Specifies the LSP on which to send the MPLS echo request.
any Allows the echo request to be sent over any available LSP.
host Specifies the FEC using an ipaddress or hostname.
prefix Specifies a prefix.
ipNetmask Specifies the prefix address.
reply-mode Specifies the return path for the MPLS echo response.
ip Requests an IP UDP reply packet. This is the default mode.
ip-router-alert Requests an IP UDP reply packet with the IP Router Alert option. If the reply is sent in an LSP, the router-alert label is inserted at the top of the label stack.
continuous Sends pings continuously until the user intervenes.
count Determines whether the size of the packet increments by one byte for each new MPLS echo request sent.
interval Specifies the time interval (in seconds) between pings.
start-size The number of payload data bytes in the MPLS ping packet. The range is from 1 - 1518 (if jumbo frames are disabled) and from 1 - the configured jumbo packet size (if jumbo frames are enabled). The default is 8 bytes.
end-size Specifies that the size of the packet increments by one byte for each new MPLS echo request sent, up to the specified maximum size for the MPLS ping packet.
ttl Sets the time-to-live value in the ping packet
from Specifies the source IP address of the packet.
hopaddress Specifies the next-hop address.

Default

Destination IP address for MPLS echo request - random, from the 127 and 128 IP address space IP TTL - 1 TTL value in MPLS echo request - 255 Destination UDP port - 3503 Payload data packet size - 8 bytes Number of pings sent - 4

Usage Guidelines

This command sends an MPLS ping packet to a FEC over an LSP. The ping command, with mpls keyword option, can be used to verify data plane connectivity across an LSP. This is useful because not all failures can be detected using the MPLS control plane. The lsp keyword and lsp_name parameter may be used to specify the LSP on which to send the MPLS echo request. The lsp keyword along with the any keyword allows the echo request to be sent over any available LSP that terminates at host, specified as an ipaddress or hostname. If no LSP exists to the specified host, the ping command fails even though an IP routed path may exist. If the optional next-hop is specified, the MPLS echo request is sent along the LSP that traverses the specified node. This option is useful for specifying an LSP when multiple LSPs exist to the specified FEC. For RSVP-TE LSPs, the FEC is implied from the LSP configuration. The TTL value in the MPLS Echo Request is set to 255.

By default, the destination IP address of the MPLS echo request is randomly chosen from the 127/8 IP address space and the IP TTL is set to 1. The destination UDP port is 3503 and the sender chooses the source UDP port.

The optional start-size keyword specifies the number of bytes to include as payload data in the MPLS ping packet. If no start-size parameter is specified, the size of the payload data is eight bytes. The minimum valid start-size value is one. The maximum start-size value is variable, depending on the type of MPLS ping packet sent, but the total size of the MPLS ping packet cannot exceed the configured jumbo packet size, if jumbo frames are enabled, or 1518 if jumbo frames are disabled. If the end-size keyword is specified, the size of the packet increments by one byte for each new MPLS echo request sent. The next MPLS echo request is not sent until the MPLS echo response for the previous packet is received. This is useful for detecting interface MTU mismatch configurations between LSRs. The switch ceases sending MPLS echo requests when the specified end-size value is reached, the MPLS ping is user interrupted, or an MPLS echo response is not received after four successive retries.

The optional reply-mode keyword is used to specify the reply mode for the MPLS echo response. When the ip option is specified, the MPLS echo reply is routed back to the sender in a normal IPv4 packet. When the ip-router-alert option is specified, the MPLS echo reply is routed back to the sender in an IPv4 packet with the Router Alert IP option set. Additionally, if the ip-router-alert option is specified and the reply route is through an LSP, the Router Alert Label is pushed onto the top of the label stack. If the reply-mode is not specified, the reply-mode ip option applies.

Example

The following example shows a ping command and the resulting display:

ping mpls lsp prefix 11.100.100.212/32
Ping(MPLS) : 4 packets, 8 data bytes, interval 1 second(s).
98 bytes from 11.100.100.212: mpls_seq=0 ttl=64 time=6.688 ms
98 bytes from 11.100.100.212: mpls_seq=1 ttl=64 time=6.036 ms
98 bytes from 11.100.100.212: mpls_seq=2 ttl=64 time=6.218 ms
98 bytes from 11.100.100.212: mpls_seq=3 ttl=64 time=6.467 ms
--- ping statistics ---
4 packets transmitted, 4 received, 0% loss
round-trip min/avg/max = 6/6/6/ms

History

This command was first available in ExtremeXOS 11.6.

Platform Availability

This command is available only on the platforms that support MPLS as described in the Feature License Requirements document.