Steps:
1. First IGP TE populates
the TEDB.
2. If CSPF option is set CSPF
uses the TEDB to calculate the best path with constraints
online.
(Note:CSPF calculation is possible
only if u have TEDB.)
Correct
3. If verbatim option is set in Cisco or "no cspf" is set in Juniper or
other networks it means that
IGP TE is not
necessary and hence cspf will not be used to find the explicit path.
TE can be accomplished with or without CSPF; CSPF is a method of
accomplishing constrained paths locally from the router, but you still
have TE if you manually determine the path, or if you use an offline tool to
determine the path. TE is essentially just directing a given
LSP along a path that may not be the
IGP path.
[Terry
Lee] Sounds correctly. But if the middle node think perhaps
it's an ASBR and try to call CSPF, it still a question. it seems no-cspf is
still out of work since no signaling can carry this
information
4. Instead strict/loose path option(manual
configuration of static path by user)
is
used to set up the explicit LSP and RSVP signalling takes place along that
path.This is without TE.
See above
comment
I want to know
clearly when TEDB (IGP TE) is required and when it is
not.
Is it true that
if CSPF path - TEDB
required
True
if strict/loose path- TEDB not required.Here TE does not come into picture
at all.
First part is true, second part
false
Thanx in advance
Kavitha