From: Lionel Gourvitch (lgourvit@xxxxxxxxx)
Date: Wed Sep 05 2001 - 13:52:22 GMT-3
Jason,
We need more information to give an answer .
Give the configuration of your routers. From which router do you ping .
Join the trace of your test.
Lionel
At 11:45 PM 9/5/2001 +0800, Jason Luo wrote:
>hi, group and Lionel
>
>thanks, Lionel.
>
>but i have the following topology to test the result.
>
>
> 172.16.x.x
> _____
>____
> |
>|
> 1.1/24*(R1)*3.2/24-------------3.1/24*(R3)*2.2/24
> |
>/
> |
>/
> |
>/
> 1.2/24*(R2)*2.1/24 ---------------------------- /
> |
> -----
>
>All 3 routers are connected with serial line(back-to-back).
>No dynamic routing protocols configured and each router has 2 "C" routes.
>I used the "debug ip icmp" on every router.
>and I lauched the "ping 172.16.255.255" on each router.
>reply only can be seen on one of the 2 directly connected lines.
>If i ping with the source address of the ethernet interface(up-up), the is
>no any response.
>
>What is wrong with me??
>thanks so much again.
>Good luck
>
>jason
>
>
>
>-----Original Message-----
>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
>Lionel Gourvitch
>Sent: 2001?9?5? 17:20
>To: Jason Luo
>Cc: ccielab@groupstudy.com
>Subject: Re: ping 172.16.255.255
>
>
>if you ping 172.16.255.255 and all your router have "ip subnet-zero"
>configured then all the devices on the "last subnet"( that contains the
>broadcast address 172.16.255.255) of 172.16.0.0 will do icmp reply. if "
>ip subnet-zero" is not configured then all the devices on 172.16.0.0 will
>do icmp reply.
>
>Hope it helps
>
>Lionel
>
>At 04:40 PM 9/5/2001 +0800, Jason Luo wrote:
> >Hi, group
> >
> >I have a question about the directed broadcast.
> >There is a network using various sub-network from the 172.16.0.0.
> >The length of subnet mask is various. (24 for lan and 30 for p-t-p)
> >Use "ping 172.16.255.255", what will happen??
> >Use "debug ip icmp" on every router, what can be seen?
> >Which switches should be opened or closed??
> >
> >Thanks alot!!!
> >
> >Jason
> >**Please read:http://www.groupstudy.com/list/posting.html
>**Please read:http://www.groupstudy.com/list/posting.html
**Please read:http://www.groupstudy.com/list/posting.html
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