RFC 3509:Alternative Implementations of OSPF Area ...
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domain


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... An OSPF routing domain can be split into several subdomains, called areas, which limit the scope of LSA flooding ...
... In OSPF domains the area topology is restricted so that there must be a backbone ...
... backbone). Consider a sample OSPF domain depicted in the Figure 1. . . ...


... [Ref1] and in this document can coexist in an OSPF domain and will function without problems. ...
... Consider an OSPF domain depicted in Figure 4. . Backbone ...



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