Cisco NCS 6000 Series User Manual

PCE is accomplished when a PCE address and client is configured for MPLS-TE. PCE communicates its PCE
address and capabilities to OSPF then OSPF packages this information in the PCE Discovery type-length-value
(TLV) (Type 2) and reoriginates the RI LSA. OSPF also includes the Router Capabilities TLV (Type 1) in
all its RI LSAs. The PCE Discovery TLV contains the PCE address sub-TLV (Type 1) and the Path Scope
Sub-TLV (Type 2).
The PCE Address Sub-TLV specifies the IP address that must be used to reach the PCE. It should be a
loop-back address that is always reachable, this TLV is mandatory, and must be present within the PCE
Discovery TLV. The Path Scope Sub-TLV indicates the PCE path computation scopes, which refers to the
PCE ability to compute or participate in the computation of intra-area, inter-area, inter-AS or inter-layer TE
LSPs.
PCE extensions to OSPFv2 include support for the Router Information Link State Advertisement (RI LSA).
OSPFv2 is extended to receive all area scopes (LSA Types 9, 10, and 11). However, OSPFv2 originates only
area scope Type 10.
For detailed information for the Path Computation Element feature see the Implementing MPLS Traffic
Engineering on module of the MPLS Configuration Guide for Cisco NCS 6000 Series Routers and the
following IETF drafts:
• draft-ietf-ospf-cap-09
• draft-ietf-pce-disco-proto-ospf-00
OSPF Queue Tuning Parameters
The OSPF queue tuning parameters configuration allows you to:
• Limit the number of continuous incoming events processed.
• Set the maximum number of rate-limited link-state advertisements (LSAs) processed per run.
• Limit the number of summary or external Type 3 to Type 7 link-state advertisements (LSAs) processed
per shortest path first (SPF) iteration within a single SPF run.
• Set the high watermark for incoming priority events.
OSPF IP Fast Reroute Loop Free Alternate
The OSPF IP Fast Reroute (FRR) Loop Free Alternate (LFA) computation supports these:
• Fast rerouting capability by using IP forwarding and routing
• Handles failure in the line cards in minimum time
OSPF Over GRE Interfaces
Cisco IOS XR software provides the capability to run OSPF protocols over Generic Routing Encapsulation
(GRE) tunnel interfaces.
For more information on GRE tunnel interfaces, see Implementing BGP on Cisco IOS XR Software module.
Routing Configuration Guide for Cisco NCS 6000 Series Routers, IOS XR Release 6.4.x
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Implementing OSPF
OSPF Queue Tuning Parameters

Cisco NCS 6000 Series Specifications

General

Brand	Cisco
Model	NCS 6000 Series
Category	Network Router
Language	English