R3303-HP HSR6800 Routers MPLS Configuration Guide

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Tuning CR-LSP setup
A CR-LSP is established through the signaling protocol based on the path calculated by CSPF using TEDB
and constraints. MPLS TE can affect CSPF calculation in many ways to determine the path that a CR-LSP
can traverse.
The configuration tasks described in this section are about CSPF of MPLS TE. They must be used in
conjunction with CSPF and the dynamic signal protocol (CR-LDP or RSVP-TE). Before performing them, be
aware of each configuration objective and its impact on your system.
Configuring the tie breaker in CSPF
CSPF only calculates the shortest path to the end of a tunnel. If multiple paths are present with the same
metric, only one of them is selected. Tie-breaking methods, in the descending order of selection priority,
include: selecting a path with the lowest bandwidth usage ratio (the used bandwidth to the maximum
reservable link bandwidth), selecting a path with the highest bandwidth usage ratio (the used bandwidth
to the maximum reserved link bandwidth), and selecting a path randomly.
To configure the CSPF tie-breaking method:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter MPLS view.
mpls N/A
3. Specify the tie breaker that a
tunnel uses to select a path
when multiple paths with the
same metric are present on
the current node.
mpls te tie-breaking { least-fill |
most-fill | random }
Optional.
The random keyword applies by
default.
4. Enter MPLS TE tunnel interface
view.
interface tunnel tunnel-number
A tunnel prefers the tie breaker
specified in the tunnel interface
view. If no tie breaker is specified
in tunnel interface view, the tunnel
uses the tie breaker specified in
MPLS view to select a path.
5. Specify the tie breaker for the
current tunnel to select a path
when multiple paths with the
same metric are present.
mpls te tie-breaking { least-fill |
most-fill | random }
Optional.
By default, no tie breaker is
specified for a specific tunnel and
the tunnel uses the tie breaker
specified in MPLS view.
The IETF DS-TE mode supports only
random path selection.
6. Submit current tunnel
configuration.
mpls te commit N/A
Configuring route pinning
Route pinning cannot be used together with reoptimization or automatic bandwidth adjustment.
To configure route pinning: