IPUB_404_C1_OSPF路由协议原理汇.ppt

* 数据库不完整，缺少asbr \ex lsa * 本例中： 如果直接在Area 2和Area 3之间发布路由信息是允许的，那么一个区域间的环路就会形成。 为了避免区域间的环路，OSPF规定直接在两个非骨干区域之间发布路由信息是不允许的，只允许在一个区域内部或者在骨干区域和非骨干区域之间发布路由信息是允许的。因此，每个区域边界路由器（ABR）都必须连接到骨干区域。 * With many years experiences on network installation, test and commissioning, ZTE engineering teams can provide customers with comprehensive Project Implementation services including site survey, network planning and design, on-site supervision, project management, infrastructure construction, system debugging, on-site training project acceptance implementation, etc. We have Captured our expertise in a Flexible Portfolio of Turnkey Services As one of the key telecom vendors in China and important worldwide telecom vendors, ZTE can not only provide operators telecom equipment such as switch, GSM, CDMA, transmission equipment, but also provide IC services for these telecom products.  完全末节区 不接收外部LSA 及汇总LSA 末节区 不接收外部的 LSA 骨干区Area 0 骨干区域 接收所有LSA. Areas 的类型 Default Default Summary Default 末节（Stub）和 完全末节（ Totally Stubby ）区域 Area 1—Totally Stubby Area 0 Area 50—Stub Summary External External Summary RIP afadjfjorqpoeru 39547439070713 afadjfjorqpoeru 39547439070713 afadjfjorqpoeru 39547439070713 afadjfjorqpoeru 39547439070713 afadjfjorqpoeru 39547439070713 afadjfjorqpoeru 39547439070713 afadjfjorqpoeru 39547439070713 afadjfjorqpoeru 39547439070713 Internal ABR1 ASBR BBone ABR2 Internal 通常只能有一个出口 域内不能有ASBR 不能是AREA 0（Backbone） 不能使用虚拟链接（Virtual links） 末节和完全末节区域的限制 单出口 Area 2 0.0.0.0 外部AS 0.0.0.0 R3 R4 X X NSSA Not So Stubby Area（非完全末节区域） To Other Area Type 5 Area 2 0.0.0.0 ExternalAS RIP Type 7 Type 7 Area 0 R3 R4 减小路由表的大小 将拓扑变化的影响限制在本地 减少 LSAs 的数量，节省 CPU 资源 支持路由汇总 Area 0 骨干区 ABRs Area 1 汇总路由 x x 一条路由信息就可以代表多个子网 路由汇总 O 172.16.8.0 255.255.252.0O 172.16.12.0 255.255.252.0O 172.16.16.0 255.255.252.0O 172.16.20.0 255.255.252.0O 172.16.24.0 255.255.252.0O 172.16.28.0 255.255.252.0 路由器B的路由表 发送至路由器C的LSAs IA 172.16.16.0 255.255.240.0 汇总路由 IA 172.16.8.0 255.255.248.0 Area 1 Ar