Proactive Threshold Monitoring For Mpls Lsp Monitoring; Multi-Operation Scheduling For The Lsp Health Monitor; Lsp Path Discovery - Cisco ASR 9000 Serie Configuration Manuals

LSP Path Discovery

The IP SLA LSP ping and IP SLA LSP traceroute operations are based on the same infrastructure used by
the MPLS LSP Ping and MPLS LSP Traceroute features, respectively, for sending and receiving echo reply
and request packets to test LSPs.

Proactive Threshold Monitoring for MPLS LSP Monitoring

Proactive threshold monitoring support for the MPLS LSP Monitor feature provides the capability for triggering
SNMP trap notifications and syslog messages when user-defined reaction conditions (such as a connection
loss or timeout) are met. Configuring threshold monitoring for an MPLS LSP monitor instance is similar to
configuring threshold monitoring for a standard IP SLAs operation.

Multi-operation Scheduling for the LSP Health Monitor

Multioperation scheduling support for the MPLS LSP Monitor feature provides the capability to easily schedule
the automatically created IP SLA operations (for a given MPLS LSP monitor instance) to begin at intervals
equally distributed over a specified duration of time (schedule period) and to restart at a specified frequency.
Multioperation scheduling is particularly useful in cases where MPLS LSP monitoring is enabled on a source
PE router that has a large number of PE neighbors and, therefore, a large number of IP SLAs operations
running at the same time.
Newly created IP SLA operations (for newly discovered BGP next-hop neighbors) are added to the same
Note
schedule period as the operations that are currently running. To prevent too many operations from starting
at the same time, the multioperation scheduling feature schedules the operations to begin at random
intervals uniformly distributed over the schedule period.
LSP Path Discovery
LSP Path Discovery (LPD) is an enhancement to MPLS LSP monitor (MPLSLM) that allows operations that
are part of an MPLSLM instance to initiate the path discovery process and to process the results. This feature
relies on the tree trace capabilities provided by the MPLS OAM infrastructure through the LSPV server.
When multiple paths with equal cost exist between two PE routers, also know as equal cost multipath (ECMP),
routers between these PE routers perform load balancing on the traffic, based on characteristics of the traffic
being forwarded (for example. the destination address in the packet). In network topologies such as this,
monitoring only one (or some) of the available paths among PE routers does not provide any guarantee that
traffic will be forwarded correctly.
LPD is configured using the path discover command.
Note LPD functionality may create considerable CPU demands when large numbers of path discovery requests
are received by the LSPV server at one time.
Cisco ASR 9000 Series Aggregation Services Router System Monitoring Configuration Guide, Release 4.2.x
208
Implementing IP Service Level Agreements