Hi Nischal,
On Feb 23, 2009, at 4:40 PM, Nischal Sheth wrote:
Acee Lindem wrote:
I have a related question about the intent of the
RFC1583Compatibility
global parameter. When set to enabled, is the underlying
objective to
emulate a RFC 1583 implementation (w.r.t. path selection among
ASBRs and
external LSAs) or is it "just" to allow compatible operation with
other
1583 routers in the network.
Offhand, I don't see much difference but I might be missing
something.
Hi Acee,
Circling back to the original question I posted, my confusion was
related to
how a RFC 2328 implementation with RFC1583Compatibility enabled
should behave
as far as picking the best ASBR route is concerned.
If you interpret RFC 2328 literally, you would use the lowest cost
route to
the ASBR irrespective of the type (intra vs. inter). In contrast,
an RFC 1583
implementation would prefer the intra-area route. It wasn't clear
to me if
this difference in behavior is intentional (hence my attempt to
differentiate
between "compatibility" and "emulation") or whether it's simply the
case that
the relevant sections are a little bit underspecified.
Based on your input, it appears that it's more of the latter than
the former.
An RFC 2328 implementation can maintain multiple routes to the ASBR
but make
sure that intra-area routes are preferred when RFC1583Compatibility
is enabled.
Alternately, it can behave exactly like an RFC 1583 implementation
and keep
only the intra-area route.
Does this sound reasonable?
Yes. My interpretation of the intent of RFC1583Compatibility is to
maintain the RFC 1583 path selection.
Thanks,
Acee
Thanks,
Nischal
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