From: Mike Kraus \(mikraus\) (mikraus@cisco.com)
Date: Thu Jul 05 2007 - 11:29:51 ART
Layer 2 to Layer 3 mappings of broadcasts do not necessarily need to
coincide with the routing protocols running over it.
Just say in scenario #1 below, you are correct in stating that if you
have OSPF configured for NBMA, you wouldn't have to configure the frame
map with the broadcast parameter as long as you used neighbor statements
(at least on the hub router). However, just say there was another
requirement to do multicast over the same link. Even though OSPF would
be running fine, you would find that multicast packets would fail to be
encapsulated and would not be transmitted.
Or, in scenario #2, just say they say you need to run RIP over the link,
but you are not allowed to use the broadcast parameter. Then, you would
have to use unicast (neighbor statements for RIP).
So, as always, the answer is "it depends". :D The only way to work
through these types of issues is to understand what each function does
independently. Sure enough whatever lab exam you get will give you a
combination that a "swiss-army-knife" configuration will not work for.
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Ben
Sent: Thursday, July 05, 2007 4:45 AM
To: John Jones
Cc: Cisco certification
Subject: Re: FR static P2P mapping on physical interfaces
John, Shiran
Thank you for responding.
I understand the use of "broadcast" in a hub and spoke scenario, and why
you need not send duplicate broadcasts from the spokes.
In scenarios with point-to-point (P2P) connections, where the
requirement is to use main interfaces, no inverse-ARP, I do not
understand when to use the "broadcast" keyword with the "frame-relay map
ip" command, and when not to do so.
The following situations come to mind:
1. If the IGP is OSPF in NBMA/P2MP-NMBA mode, do not use "broadcast"
keyword.
2. If the IGP is RIPv2/EIGRP, use "broadcast" keyword.
Are the above summations correct?
If you use the "broadcast" keyword in situation 1. above, would you be
penalised?
Thanks
Ben
On 7/5/07, John Jones <acer0001@gmail.com> wrote:
>
> The "broadcast " keywork only needs to be used on one of the mappings
> to that DLCI. This avoids multiple broadcast packets from being
> generated to the same destination. Some labs have this as a
requirement as well.
>
> John
>
>
> On 7/5/07, Ben <bmunyao@gmail.com> wrote:
> >
> > Hi Group
> >
> > Some IE labs solution guides use the broadcast keyword on FR static
> > mappings for P2P FR on physical interfaces, while others do not.
> >
> > How do we determine when to use this keyword?
> >
> > Thanks
> >
> > Ben
> >
> > ____________________________________________________________________
> > ___ Subscription information may be found at:
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