Foundry NetIron M2404C and M2404F Metro Access Switches
Configuring MPLS and H-VPLS (Rev. 03)
Multiprotocol Label Switching
© 2008 Foundry Networks, Inc
Page 24 of 113
Example 2 (Unsuccessful lsp ping)
device-name
#
mpls lsp-ping lsp tunnel1 count 20
Sending 20 packet(s), timeout is 2 sec:
Legend: X - error, . - timeout, R - transit, ! - egress
Press Esc for break
....................
20 packets sent, 0 packets received, 100% packet loss
round-trip min/avg/max = 0/0/0 ms
Performing an LSP Hop-by-Hop Traceroute
The
mpls lsp-trace
command, in Privileged (Enable) mode, verifies an LSP hop-by-hop path of
the packet. This is accomplished by sending in-band MPLS echo packets and using time-to-live
(TTL) settings to force expiration of the TTL along an LSP. MPLS LSP Traceroute incrementally
increases the TTL value in its MPLS echo requests (TTL = 1, 2, 3, 4,...) to discover the
downstream mapping of each successive hop. Each router along the way returns an MPLS echo
reply containing information about the transit hop in response to the TTL-expired MPLS packet.
Command Syntax
device-name
#
mpls lsp-trace
[
lsp
LSP-NAME
|
prefix
A.B.C.D/M
] [
size
<octets>
] [
ttl <label-ttl>
] [
count <count>
] [
timeout
<timeout>
] [
draft3
|
rfc
]
Argument Description
lsp LSP-NAME
(Optional). Specifies the name of the LSP to trace.
prefix A.B.C.D/M
(Optional). Specifies the prefix of the Forwarding Equivalence Class
(FEC), the egress of which will be traced.
size <octets>
(Optional). Specifies the minimum packet size in octets. The packet
is padded with NULL characteristics to the specified size. The range
is <60-1300>.
timeout <timeout>
Number of seconds to wait for a connectivity test reply. The range is
<1-120> seconds. The default value is 2 sec.
ttl <label-ttl>
(Optional). Indicates the maximum time to live and is used to
discover the number of downstream hops to the destination router in
range <1-255>. The default TTL (time-to-live) is 30.
count <count>
(Optional). Number of messages to be sent. The default value is 1.
The range is <1-100>.
draft3
(Optional). Sets a packet format compliant with draft 3 of the LSP
Ping specification.
rfc
(Optional). Sets a packet format compliant with RFC4379.
Example 1 (Successful lsp trace):
device-name
#
mpls lsp-trace lsp tunnel1
Sending 1 packet(s), timeout is 2 sec:
Legend: X - error, . - timeout, R - transit, ! - egress
Press Esc for break
R 30.0.0.2 code: 8,1 (Label switched)
! 11.0.0.3 code: 3,1 (Egress router)
2 packets sent, 2 packets received, 0% packet loss