Re: ARP Frame relay

From: Sean.Zimmerman@clubcorp.com
Date: Tue May 15 2007 - 17:52:25 ART

Thanks Brian.

I've taken three labs, and every time, especially the last time, I really
had to struggle to answer many of the faults in the score report. I
understand inverse arp, but I don't understand why Cisco even bothered
introducing the 'no arp frame-relay' command. I've seen it in ATM-Frame
SIW examples, and I've read it's a dependency for auto-install. I'm just
trying to make sure I didn't miss something fundamental such as this.

Sean

Brian Dennis <bdennis@internetworkexpert.com>
Sent by: nobody@groupstudy.com
05/15/2007 03:16 PM
Please respond to
Brian Dennis <bdennis@internetworkexpert.com>

To
<Sean.Zimmerman@clubcorp.com>, Sergio Silva <spmsilva@gmail.com>
cc
Cisco certification <ccielab@groupstudy.com>, Cisco Key
<ciscokey@googlemail.com>, <nobody@groupstudy.com>
Subject
Re: ARP Frame relay

Sean,
    No. You are not any safer applying a command that has no effect.

    When I grade a mock lab and see extra commands that aren9t needed
whatsoever it just shows that the candidate doesn9t fully understand the
topic/technology. When the proctors are grading your real lab you want
your
solutions to appear as precise as possible. Don9t apply commands that
have
no effect 3just to be safe2. 

--

Brian Dennis, CCIE4 #2210 (R&S/ISP-Dial/Security/SP)
bdennis@internetworkexpert.com

Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987
Direct: 775-745-6404 (Outside the US and Canada)

On 5/15/07 11:34 AM, "Sean.Zimmerman@clubcorp.com"
<Sean.Zimmerman@clubcorp.com> wrote:

>
> I'm kind of getting the impression here that if we're asked to disable
> automatic l2-l3 frame-relay mapping methods that we should now issue a
'no
arp
> frame-relay' in addition to 'no frame inv'. Should be safe, right?
>
> Sean
>
>
>
> "Sergio Silva" <spmsilva@gmail.com>
> Sent by: nobody@groupstudy.com 05/15/2007 01:23 PM
> Please respond to
> "Sergio Silva" <spmsilva@gmail.com>
> To
> "Brian Dennis" <bdennis@internetworkexpert.com>
> cc
> "Cisco Key" <ciscokey@googlemail.com>, "Cisco certification"
> <ccielab@groupstudy.com>
> Subject
> Re: ARP Frame relay
>
>
>
>
> Thanks Brian
>
> Its just its documented in practical studies as per the following
>
>    Router(config-if)no frame-relay inverse-arp  Disables the sending of
> Inverse ARP requests.  Use this command in conjunction with no arp
> frame-relay to prevent the dynamic mapping of PVCs.  Router(config-if)no
arp
> frame-relay Disables ARP responses.   Use this in conjunction with the
no
> frame-relay inverse-arp command.
>
> So I just needed clarity on this
>
> thank
> p
>
>
>
> On 15/05/07, Brian Dennis <bdennis@internetworkexpert.com> wrote:
>> >
>> > The "no arp frame-relay" command does not stop the router from
sending
>> > inverse-ARP requests or replying to inverse-ARP requests.  The
command
>> > does
>> > not have any effect on inverse-ARP whatsoever.  If you think about it
>> > there
>> > isn't support for ARP in Frame Relay to begin with so why would you
ever
>> > need to disable it?  Frame Relay supports inverse-ARP but not ARP.
>> >
>> > Inverse Address Resolution Protocol
>> > http://www.internetworkexpert.com/rfc/rfc1293.txt
>> >
>> > HTH,
>> >
>> > Brian Dennis, CCIE4 #2210 (R&S/ISP-Dial/Security/SP)
>> > bdennis@internetworkexpert.com
>> >
>> > Internetwork Expert, Inc.
>> > http://www.InternetworkExpert.com
>> > Toll Free: 877-224-8987
>> > Direct: 775-745-6404 (Outside the US and Canada)
>> >
>> >
>> >
>> > On 5/15/07 5:29 AM, "Cisco Key" <ciscokey@googlemail.com> wrote:
>> >
>>> > > Hi Group
>>> > >
>>> > > I do apologise if this question has been asked a million times
before,
>> > but I
>>> > > have been searching the archives and have still not found any
definitive
>>> > > answer on the use/uselessness of ARP Frame-relay,
>>> > >
>>> > > I have found the following:
>>> > >
>>> > >    ARP Frame-relay no arp frame-relay" also to circumvent sending
out
ip
>>> > > address to DLCI binding information no arp frame-relay that this
will
>> > kill
>>> > > auto install  Router(config-if)no frame-relay inverse-arp 
Disables
the
>>> > > sending of Inverse ARP requests.  Use this command in conjunction
with
>> > no
>>> > > arp frame-relay to prevent the dynamic mapping of
>> > PVCs.  Router(config-if)no
>>> > > arp frame-relay Disables ARP responses.   Use this in conjunction
with
>> > the
>>> > > no frame-relay inverse-arp command.
>>> > >
>>> > > Is this command really needed, I know this use to be used with
ATM,
but
>> > I do
>>> > > not really see the use of this command if no frame-relay
inverse-arp
>> > does
>>> > > the job
>>> > >
>>> > > Please comment
>>> > >
>>> > > Thanks
>>> > > Paul
>>> > >
>>> > >

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