Experiment to test the RIP timers, but failure. Ask for help. Thanks.

darkcat9th

I want to test how the RIP timers work, but failure.
My experiment as follow.




I wanna get my seven expectations, but just 1 and 2 is ok.


the question:
When I shut down the interface f0/0 on R1.
R1 debug returns me the route poison and the ip route “192.1.1.0、24” is flushed immediately.
Then the 192.1.1.0/24 RIP information will be deleted ** RIP database after 60 seconds.
That's not my expectations.

My understanding of 4 RIP Timers is wrong, isn't it?

How should I design a experiment to test the RIP Timers?









[ 本帖最后由 darkcat9th 于 2009-4-8 16:17 编辑 ]

admin

Why did you want  to  describe your quenstion in english? if you do it in chinese more people can understand what you said and can answer your question.
When you shutdown a interface which a router directly connected,the router send a route poison "upda,te" to it's neighbor immediately.the router which you shutdown it's directly connected interface consider this route is invalid,and the timer  alreadly have passed the invalid time,so after 60 seconds the flush timer expired the route is deleted.

[ 本帖最后由 admin 于 2009-4-9 08:37 编辑 ]

darkcat9th

谢谢你为我解答~

因为我设计实验的时候描述是用英文，就想尝试一下~

我建议大家以后如果可能，用双语来描述自己的问题（中文和英文）来练习一下吧~我想会有更好的网络方面的英文环境~

然后，就是说这个实验的失败就是因为shutdown直连接口。那么怎样才会触发Invalid Timer呢。

admin

你可以使用访问控制列表 拒绝upda,te的传出

darkcat9th

嗯，我改一下实验再试试。希望能够成功，谢谢你。


另：
如果阻止"up`date”传出的话会不会影响 holddown timer 的工作呢？
“When a router receives an up`date f`rom a neighbor indicating that a previously accessible network isn’t working and is inaccessible, the holddown timer will start. If a new up`date arrives f`rom a neighbor with a better metric than the original network entry, the holddown is removed and data is passed. But if an up`date is received f`rom a neighbor router before the holddown timer expires and it has an equal or lower metric than the previous route, the up`date is ignored and the holddown timer keeps ticking. This allows more time for the network to stabilize before trying to converge.”
引自ccna study guide sybex版第224页
如书中描述，当路由器收到一个来自邻居的更新，这个更新指出先前可达的网络不再工作或者不可达，holddown定时器开启。如果组织了邻居"up`date"的传出，那该路由器的 holddown 定时器会不会工作？

感谢你耐心的解答  







   怎么"up`date"、"f`rom"都要过滤啊...

[ 本帖最后由 darkcat9th 于 2009-4-9 15:55 编辑 ]

admin

根据我的观察holddown timer从来不起效

darkcat9th

对啊！做这个实验的时候，我也发现holddown timer怎么没用呢？
就是把一个端口shutdown以后再no shut再shutdown再no shut（这个效果应该类似于网络时断时续吧？拔插网线），都是立即在邻居路由表中起效的！

理论上应该会等holddown time到了以后才会进入路由表的啊，怎么回事

admin

我上次看一个老外的文章 他说现在的网络这个timer没必要起效

darkcat9th

恩，谢谢，我google一下这个文章看看

admin

好像是一个人的评论 不必客气