From: David C Prall (dcp@xxxxxxxxxxx)
Date: Wed Sep 05 2001 - 22:43:13 GMT-3
Jason,
What version of code, 12.0 and higher "no ip directed-broadcast" is
configured by default. But, you will get a response from the nearest router
interface. This is doing the ping from an end system, doing it from the
router may be completely different.
David C Prall dcp@dcptech.com http://dcp.dcptech.com
----- Original Message -----
From: "Jason Luo" <luoz@cisco.com>
To: "Lionel Gourvitch" <lgourvit@cisco.com>
Cc: <ccielab@groupstudy.com>
Sent: Wednesday, September 05, 2001 11:45 AM
Subject: RE: ping 172.16.255.255
> 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
**Please read:http://www.groupstudy.com/list/posting.html
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