课件4：OSPF资料.ppt

* 每个LSA的有效时间缺省为30分钟。LSA超时后，产生此LSA的原路由器必须再次向网络发送LSU以说明这条链路仍然有效。 当每个路由器收到LSU后： 1 如果此项原来存在并且收到的LSU有同样的内容，它就重置LSA定时器并向DR发送LSAck。 2 如果此项原来存在并且收到的LSU有更新的内容，它就发送LSR去请求此表项的所有内容。 3 如果此项原来存在并且收到的LSU有陈旧的内容，它就使用自己的信息发送LSU。 * 路由器之间不同的网络连接类型，其Neighbor关系也不同： Broadcast multiaccess----例如LAN。邻居关系是通过组播方式的hello动态学习构成的。 Point-to-Point---例如串行链路。邻居关系由链路两端的路由器构成，在这种情况下，不需要也不使用DR或BDR。 Nonbroadcast multiaccess---例如Frame Relay。邻居关系由手工配置完成。 * router ospf process-id process-id 路由器上OSPF的进程号，以区分同一个路由器上的多个OSPF进程。不同路由器上的进程号不需要一致。在同一个路由器上不建议运行多个OSPF进程。 network address wildcard-mask area area-id address 可以是网络地址、子网或接口地址。告诉路由器从哪条链路宣告、从哪条链路接收其他路由器的宣告，并且宣告哪个网络。 wildcard-mask 反码。0表示“匹配”，1表示“忽略”。如果使用接口地址，使用反码 0.0.0.0。 area area-id 表明地址所属的area。可以是一个数字也可以是IP地址。对一个单独的area, ID必须等于0。 * show ip protocol Displays parameters about timers,filters,metrics,networks,and other information for the entire router. show ip route Displays the routes known to the router and how they were learned.This is one of the best ways to determine connectivity between the local router and the rest of the internetwork. show ip ospf interface Verifies that interfaces have been configured in the intended areas.If no loopback address is specified,the interface with the highest address is taken as the router ID.It also gives the timer intervals including the hello interval and shows the neighbor adjacencies. * show ip protocol Displays parameters about timers,filters,metrics,networks,and other information for the entire router. show ip route Displays the routes known to the router and how they were learned.This is one of the best ways to determine connectivity between the local router and the rest of the internetwork. show ip ospf interface Verifies that interfaces have been configured in the intended areas.If no loopback address is specified,the interface with