From: Han Ghee Chia (han_ghee@yahoo.com.sg)
Date: Wed Feb 13 2008 - 03:35:14 ARST
I believe that explains why some CCIEs don't know even depth & breath. But
they still passed the lab exam, anyway.
----- Original Message ----
From:
Rik Guyler <rik@guyler.net>
To: Jersey Guy <guy.jersey@gmail.com>; Cisco
certification <ccielab@groupstudy.com>
Sent: Wednesday, 13 February 2008
5:36:30
Subject: RE: can't understand BGP Theory
Hmmm...maybe but I would
think this level of BGP understanding would be more
for the SP track than R/S.
Definitely agree that you have to know what MED
is, how to use it and how to
configure it if needed in the lab but the
underlying theory about route
leakage and the such may be over the top for
R/S IMHO. Optimal routing has
never been a focus in the lab.
Rik
-----Original Message-----
From:
nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Jersey Guy
Sent: Monday, February 11, 2008 9:24 PM
To: Cisco certification
Subject: can't
understand BGP Theory
From Halabi's book, Internet Routing Architectures, 2nd
edition, page 167:
*MEDs are somewhat handicapped by aggregation scenarios in
which providers
announce a given CIDR block from multiple locations in their
network and
suppress the smaller routes from the block. Utilizing MEDs in this
scenario
could potentially result in suboptimal routing because the
more-specific
routes of the CIDR block could be scattered throughout the AS
and MEDs
associated with more-granular routes are no longer available.
When
using MEDs to perform what's commonly referred to as best-exit routing,
some
providers leak the more-specifics of their CIDR blocks to select peers
to
remove the offshoots introduced by aggregation. The problem with this is
that
controlling the more-specific announcements is sometimes complex, and
failure
to do so can result in some very suboptimal routing situations.
*
I read the
above two paragraphs five times but didn't understand it. Which
of the
following is true:
a) I have no choice but to understand this stuff, to pass
the lab. I need to
understand *everything* in Halabi's book, period.
b) The
lab is tough but not THAT tough. I can skip certain convoluted
sections of
every topic and still manage to get by.
c) Forget it. I am not going to make
it. MED is a piece of cake; what's so
hard to understand??
d) I need to read
"How to grow gray matter and raise IQ" book before
Halabi's.
Thing is....how
thoroughly do I need to pound away at theory/reading before
hitting the
equipment, lab scenarios and excercises?
thanks, JG
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