Cisco Cisco IOS Software Release 12.0(13)S7
IP SLAs—LSP Health Monitor
Information About the LSP Health Monitor
3
Cisco IOS Release: Multiple releases (see the Feature History table)
•
Discovery of BGP next hop neighbors based on local VPN routing or forwarding instances (VRFs)
and global routing tables
and global routing tables
•
Multioperation scheduling of IP SLAs operations
How the LSP Health Monitor Works
The LSP Health Monitor feature provides the capability to proactively monitor Layer 3 MPLS VPNs.
The general process for how the LSP Health Monitor works is as follows:
The general process for how the LSP Health Monitor works is as follows:
1.
The user enables the BGP next hop neighbor discovery process on a given PE router.
When this process is enable, a database of BGP next hop neighbors in use by any VRF associated
with the source PE router is generated based on information from the local VRF and global routing
tables. For more information about the BGP next hop neighbor discovery process, see the
with the source PE router is generated based on information from the local VRF and global routing
tables. For more information about the BGP next hop neighbor discovery process, see the
.
2.
The user configures an LSP Health Monitor operation.
Configuring an LSP Health Monitor operation is similar to configuring a standard IP SLAs
operation. To illustrate, all operation parameters for an LSP Health Monitor operation are
configured after an identification number for the operation is specified. However, unlike standard IP
SLAs operations, these configured parameters are then used as the base configuration for the
individual IP SLAs LSP ping and LSP traceroute operations that will be created by the LSP Health
Monitor.
operation. To illustrate, all operation parameters for an LSP Health Monitor operation are
configured after an identification number for the operation is specified. However, unlike standard IP
SLAs operations, these configured parameters are then used as the base configuration for the
individual IP SLAs LSP ping and LSP traceroute operations that will be created by the LSP Health
Monitor.
3.
The user configures proactive threshold violation monitoring for the LSP Health Monitor operation.
4.
The user configures multioperation scheduling parameters for the LSP Health Monitor operation.
5.
Depending on the configuration options chosen, the LSP Health Monitor automatically creates
individual IP SLAs LSP ping or LSP traceroute operations for each applicable BGP next hop
neighbor.
individual IP SLAs LSP ping or LSP traceroute operations for each applicable BGP next hop
neighbor.
For any given LSP Health Monitor operation, only one IP SLAs LSP ping or LSP traceroute
operation will be configured per BGP next hop neighbor. However, more than one LSP Health
Monitor operation can be running on a particular PE router at the same time (for more details, see
the note at the end of this section).
operation will be configured per BGP next hop neighbor. However, more than one LSP Health
Monitor operation can be running on a particular PE router at the same time (for more details, see
the note at the end of this section).
6.
Each IP SLAs LSP ping or LSP traceroute operation measures network connectivity between the
source PE router and the discovered destination PE router.
source PE router and the discovered destination PE router.
Note
More than one LSP Health Monitor operation can be running on a particular PE router at the
same time. For example, one LSP Health Monitor operation can be configured to discover BGP
next hop neighbors belonging to the VRF named VPN1. On the same PE router, another LSP
Health Monitor operation can be configured to discover neighbors belonging to the VRF named
VPN2. In this case, if a BGP next hop neighbor belonged to both VPN1 and VPN2, then the PE
router would create two IP SLAs operations for this neighbor—one for VPN1 and one for VPN2.
same time. For example, one LSP Health Monitor operation can be configured to discover BGP
next hop neighbors belonging to the VRF named VPN1. On the same PE router, another LSP
Health Monitor operation can be configured to discover neighbors belonging to the VRF named
VPN2. In this case, if a BGP next hop neighbor belonged to both VPN1 and VPN2, then the PE
router would create two IP SLAs operations for this neighbor—one for VPN1 and one for VPN2.
Adding and Deleting IP SLAs Operations from the LSP Health Monitor Database
The LSP Health Monitor receives periodic notifications about BGP next hop neighbors that have been
added to or removed from a particular VPN. This information is stored in a queue maintained by the LSP
Health Monitor. Based on the information in the queue and user-specified time intervals, new IP SLAs
operations are automatically created for newly discovered PE routers and existing IP SLAs operations
are automatically deleted for any PE routers that are no longer valid.
added to or removed from a particular VPN. This information is stored in a queue maintained by the LSP
Health Monitor. Based on the information in the queue and user-specified time intervals, new IP SLAs
operations are automatically created for newly discovered PE routers and existing IP SLAs operations
are automatically deleted for any PE routers that are no longer valid.