3Com Switch 8800 Family Configuration Guide

Troubleshooting OSPF Faults 337
Figure 86 OSPF areas
■ The backbone area (Area 0) cannot be configured as the stub area and the
virtual link cannot pass through the stub area. That is, if a virtual link has been
set up between RTB and RTC, neither Area1 nor Area0 can be configured as a
stub area. In the figure above, only Area 2 can be configured as the stub area.
■ Routers in the stub area cannot receive external routes.
■ The backbone area must guarantee the connectivity of all nodes.
RTA RTB RTC RTD
area0 area1 area2
RTA RTB RTC RTD
area0 area1 area2