2.OSPF中rid修改后，如何生效，使用clear ip ospf PRocess這條命令重新對ospf進(jìn)程進(jìn)行啟動(dòng)或重啟路由器不好使？要重啟所有使用ospf的router才會(huì)修改rid 答：When OSPF is configured on a router, the router interfaces are polled and interfaces that are up are enabled with OSPF. As interfaces become more complex and the amount of interfaces increase, the time for interfaces to come up also increases, and there is a slight chance that OSPF will poll the interface before its state is fully up. This can result in the interface being up, but OSPF not being enabled on it. The default number of times OSPF polls the interfaces has been increased from 0 to 10 in order to avoid this situation. If you're running OSPF and upgrading to Cisco IOS® Software release 12.0(8)S, you'll notice the ip ospf interface-retry 0 is automatically added to every interface. This value is the old default value. The new default number of retry times is 10. The router displays the old behavior so the command shows up in the configuration. Note: The ip ospf interface-retry 0 command is harmless, and OSPF continues to function normally whether or not you change the interface retry value. Solution Only configure ip ospf interface-retry 10 on all interfaces if you don't want this command to appear in your router's configuration. As 10 is the new default value the command will no longer appear in the configuration. This problem is documented as Cisco bug ID CSCdp64394. If you are a registered customer and you have logged in, you can view the bug details.
3.OSPF不能建立鄰居關(guān)系的原因? 答：建立neighbor考慮如下的因素 1、hello包間隔不一致 2、netmask不匹配（p2p和vlink除外） 3、E-bit（處理外部路由的規(guī)定） 4、router dead time 5、auth
