Subject: Area Parameters

From: Igor Miroshnik <[email-masked]>
Date: Tue, 9 Dec 2003 11:54:51 -0500

Group,

RFC 2328 says (listing, inter alia, StubDefaultCost):

"   C.2 Area parameters

    All routers belonging to an area must agree on that area's
configuration. Disagreements between two routers will lead to an inability
for adjacencies to form between them, with a resulting hindrance to the
flow of routing protocol and data traffic."

On the other hand,

"   12.4.3.1. Originating summary-LSAs into stub areas

... Note that StubDefaultCost need not be configured identically in all of
the stub area's area border routers."

1) Don't the quoted passages contradict?
2) What about ospfAreaSummary: should all routers in a stub area agree upon
this parameter? If so, how can they indicate that: no bit in area options
tells about Totally Stubby Areas?

Thank you,
Igor

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From: Acee Lindem <[email-masked]>
Date: Wed, 10 Dec 2003 06:19:26 -0500

>flow of routing protocol and data traffic."

Hi Igor,

The general statement above applies to area type. It probably should be
more explicit. The OSPF
specification evolved over a number or iterations and originally the
authentication type was also
specified at an area level.

>1) Don't the quoted passages contradict?
Somewhat - when in doubt, match on the  more specific statement.

>tells about Totally Stubby Areas?
They don't necessarily need to agree if you want to prefer one ABR as an
exit point for OSPF
inter-area traffic.