H3C S7500 Series Ethernet Switches Operation Manual

Operation Manual – Routing Protocol
H3C S7500 Series Ethernet Switches Chapter 4 OSPF Configuration
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Area 0
Area 1
Area 2
ABRABR
Transit Area
Virtual Link
Router A Router B Router C
Router D
Figure 4-5 OSPF area
z A virtual link cannot pass through a stub area. The backbone area (area 0)
cannot be configured as a stub area. So, if a virtual link has been set up between
RTB and RTC, neither area 1 nor area 0 can be configured as a stub area. In
Figure 4-5, only area 2 can be configured as a stub area.
z A router in a stub area cannot receive external routes.
z The backbone area must guarantee the connectivity between various nodes.