34-42
Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 34 Configuring MPLS, MPLS VPN, MPLS OAM, and EoMPLS
Understanding MPLS OAM
Understanding MPLS OAM
MPLS OAM helps service providers monitor label-switched paths (LSPs) and quickly isolate MPLS
forwarding problems to assist with fault detection and troubleshooting in an MPLS network. The switch
supports these MPLS OAM features:
•
LSP ping/traceroute LDP IPv4 version 3
•
Any Transport over MPLS (AToM) Virtual Circuit Connection Verification (VCCV) to use MPLS
LSP Ping to test the pseudowire section of an AToM virtual circuit (VC).
•
IP Service Level Agreements (IP SLAs) to monitor MPLS LSP networks and IP SLAs Health
Monitor to automatically generate LSP ping and traceroute to BGP VPN neighbors.
Note
In Cisco IOS Release 12.2(37)SE, IP SLAs support implemented nonstandard IP SLAs
command-line interface commands, using the rtr global configuration command to put the
switch into response time reporter (RTR) configuration mode. Beginning with Cisco IOS
Release 12.2(40)SE, the switch uses the standard IP SLAs configuration commands, using the
ip sla global configuration command to put the switch into IP SLAs configuration mode. See
Chapter 31, “Configuring Cisco IOS IP SLAs Operations,”
for more information on configuring
IP SLAs.
For more information about MPLS OAM, see the MPLS LSP Ping/Traceroute for LDP/TE, and LSP Ping
for VCCV feature module at this URL:
http://www.cisco.com/en/US/docs/ios/mpls/configuration/guide/mp_ldp_te_lsp_vccv_ps6922_TSD_
Products_Configuration_Guide_Chapter.html
Note
The switch does not support all of the commands referenced in the MPLS LSP Ping/Traceroute feature
module. For a list of commands that are visible in the CLI help, but not supported on the switch, see
Appendix C, “Unsupported Commands in Cisco IOS Release 12.2(52)EY.”
Beginning with Cisco IOS Release 12.2(40)SE, the switch supports these additional keywords for the
ping mpls and traceroute mpls privileged EXEC commands to support RFC4379:
•
Entering the dsmap keyword with the ttl keyword to the ping command allows you configure a
MPLS echo request from the source router to expire at a transit router with a wildcard downstream
map to obtain downstream information from the transit router.
•
Entering the flags fec keyword configures the source router to force the transit router to validate the
target forwarding equivalence class (FEC).
•
Entering the force-explicit-null keyword adds a Null label to the end of the label stack to allow the
destination provider-edge device to distinguish between traffic that has been rejected by the
destination provider router and traffic that arrives untagged.
•
Entering the interval keyword allows you to specify the echo request packet send interval.
•
Entering the output interface interface-id keywords provides path information as input to the LDP
IPv4 ping and traceroute configuration to force echo packets through the same paths for more
detailed analysis for LSP debugging.
•
Entering the repeat keyword specifies the number of retries attempted if an echo request times out
before an echo reply is received.
