From: Brian Dennis (bdennis@internetworkexpert.com)
Date: Tue Dec 14 2004 - 01:25:34 GMT-3
Short answer, yes it will work properly. The only problem you may run
into is with area summarization (i.e. two area 1's summarizing the same
address space).
Long answer, see RFC 2328
(http://www.internetworkexpert.com/rfc/rfc2328.txt)
<QUOTE>
3.7. Partitions of areas
OSPF does not actively attempt to repair area partitions. When
an area becomes partitioned, each component simply becomes a
separate area. The backbone then performs routing between the
new areas. Some destinations reachable via intra-area routing
before the partition will now require inter-area routing.
However, in order to maintain full routing after the partition,
an address range must not be split across multiple components of
the area partition. Also, the backbone itself must not
partition. If it does, parts of the Autonomous System will
become unreachable. Backbone partitions can be repaired by
configuring virtual links (see Section 15).
Another way to think about area partitions is to look at the
Autonomous System graph that was introduced in Section 2. Area
IDs can be viewed as colors for the graph's edges.[1] Each edge
of the graph connects to a network, or is itself a point-to-
point network. In either case, the edge is colored with the
network's Area ID.
A group of edges, all having the same color, and interconnected
by vertices, represents an area. If the topology of the
Autonomous System is intact, the graph will have several regions
of color, each color being a distinct Area ID.
When the AS topology changes, one of the areas may become
partitioned. The graph of the AS will then have multiple
regions of the same color (Area ID). The routing in the
Autonomous System will continue to function as long as these
regions of same color are connected by the single backbone
region.
</QUOTE>
Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
bdennis@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987
Direct: 775-745-6404 (Outside the US and Canada)
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Hans None
Sent: Monday, December 13, 2004 8:10 PM
To: ccielab@groupstudy.com
Subject: ospf discontinuous areas
All,
Can ospf discontinuous areas work properly (non area 0).
For example, there are multiple area 1 which are discontinuous to each
other. Will this work properly?
Thanks,
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