Juniper Networks J-Series manual Checking Mpls Connections from the CLI

J-series™ Services Router Administration Guide

Table 116: CLI ping Command Options (continued)

Option	Description
ttl number	(Optional) Sets the time-to-live (TTL) value for the ping request packet. Specify a value from 0
	through 255.
wait seconds	(Optional) Sets the maximum time to wait after sending the last ping request packet. If you do
	not specify this option, the default delay is 10 seconds. If you use this option without the count
	option, the Services Router uses a default count of 5 packets.
detail	(Optional) Displays the interface on which the ping response was received.
verbose	(Optional) Displays detailed output.

Following is sample output from a ping command:

user@host> ping host3 count 4
PING host3.site.net (176.26.232.111): 56		data bytes
64	bytes from 176.26.232.111: icmp_seq=0	ttl=122 time=0.661 ms
64	bytes from 176.26.232.111: icmp_seq=1	ttl=122 time=0.619 ms
64	bytes from 176.26.232.111: icmp_seq=2	ttl=122 time=0.621 ms
64	bytes from 176.26.232.111: icmp_seq=3	ttl=122 time=0.634 ms

--- host3.site.net ping statistics ---

4 packets transmitted, 4 packets received, 0% packet loss round-trip min/avg/max/stddev = 0.619/0.634/0.661/0.017 ms

The fields in the display are the same as those displayed by the J-Web ping host diagnostic tool. For information, see “Ping Host Results and Output Summary” on page 218.

Checking MPLS Connections from the CLI

Use the ping mpls commands to diagnose the state of LSPs, Layer 2 and Layer 3 VPNs, and Layer 2 circuits. When you issue a command from a Services Router operating as the inbound node at the entry point of an LSP or VPN, the router sends probe packets into the LSP or VPN. Based on how the LSP or VPN outbound node at the remote endpoint of the connection replies to the probes, you can determine the connectivity of the LSP or VPN.

Each probe is an echo request sent to the LSP or VPN exit point as an MPLS packet with a UDP payload. If the outbound node receives the echo request, it checks the contents of the probe and returns a value in the UDP payload of the response packet. If the Services Router receives the response packet, it reports a successful ping response. Responses that take longer than 2 seconds are identified as failed probes.

Alternatively, you can use the J-Web ping MPLS tool. For more information, see “Checking MPLS Connections from the J-Web Interface” on page 219.

Before using ping mpls commands in your network, read “Ping MPLS

Preparation” on page 215.

232■ Using CLI Diagnostic Commands