DELL 8132 ユーザーズマニュアル

OSPF Commands

OSPF is a link-state protocol. PowerConnect OSPF supports variable-length 

subnet masks. PowerConnect OSPF only operates over VLAN interfaces.
OSPF operates within a hierarchy. The largest entity within the hierarchy is 

the autonomous system (AS), a collection of networks under a common 

administration sharing a common routing strategy. This is sometimes called a 

routing domain. An AS can be divided into a number of areas or groups of 

contiguous networks and attached hosts. Routers within the same area share 

the same information, so they have identical topological databases. 

Information is sent in the form of link-state advertisements (LSAs) to all 

other routers within the same hierarchical area. An area's topology is not 

visible to routers outside the area.
Two different types of OSPF routing occur as a result of area partitioning: 

Intra-area and Inter-area. Intra-area routing occurs if a source and destination 

are in the same area. Inter-area routing occurs when a source and destination 

are in different areas. An OSPF backbone distributes information between 

areas.
For IPv4 networks, PowerConnect routing supports OSPF version 2 in 

accordance with RFC 2328. The PowerConnect routing also provides a 

compatibility mode for the RFC 1583 OSPF specification, which allows 

interoperability with OSPF version 2 routers using the older implementation.
The PowerConnect OSFPv2 implementation supports point-to-point 

operation on Ethernet interfaces. The user can configure an OSPFv2 

interface to run in broadcast or point-to-point mode. When there are only 

two routers attached to the link, OSPFv2 point-to-point mode has the 

advantage of not requiring designated router election or origination of a 

network LSA for the LAN. This makes the protocol more efficient. 

PowerConnect also supports OSPFv3 for use with IPv6 networks.
The PowerConnect routing OSPF NSSA feature supports RFC 3101, The 

OSPF Not-So-Stubby Area (NSSA) Option.

2CSPC4.X8100-SWUM102.book  Page 1195  Friday, March 15, 2013  8:56 AM