Ericsson ECN330, Руководство пользователя

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Configuring the ECN330-switch
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1553-KDU 137 365 Uen D 2006-06-16
6.20.10.6 Configuring Network Area Addresses
OSPF protocol broadcast messages (that is, Link State Advertisements or
LSAs) are restricted by area to limit their impact on network performance. A
large network should be split up into separate OSPF areas to increase network
stability, and to reduce protocol traffic by summarizing routing information into
more compact messages. Each router in an area shares the same view of the
network topology, including area links, route summaries for directly connected
areas, and external links to other areas.
Command Usage
• Use the Network Area Address Configuration page to specify an Area
ID and the corresponding network address range. Each area identifies
a logical group of OSPF routers that actively exchange LSAs to ensure
that they share an identical view of the network topology.
• Each area must be connected to a backbone area. This area passes
routing information between other areas in the autonomous system.
The default value 0.0.0.0 is used as the Area ID for the backbone. All
routers must be connected to the backbone, either directly, or through a
virtual link if a direct physical connection is not possible.
• An area initially configured through the Network Area Address
Configuration page is set as a normal area (or transit area) by default.
A normal area can send and receive external Link State Advertisements
(LSAs). If necessary, use the Area Configuration page to configure an
area as a stubby area that cannot send or receive external LSAs, or a
not-so-stubby area (NSSA) that can import external route information
into its area (page 442).
• An area must be assigned a range of subnetwork addresses. This area
and the corresponding address range forms a routing interface, and can
be configured to aggregate LSAs from all of its subnetwork addresses
and exchange this information with other routers in the network
(page 446).
Command Attributes
• IP Address – Address of the interfaces to add to the area.
• Netmask – Network mask of the address range to add to the area.