RE: adverising loopback in OSPF Domain

A couple of simple rules to remember, if you have redistributed connected on any interface for a previous task, any other connected routes on the router will need to be included if they aren't already covered by network statements. The second is that the route must appear in the RIB of the protocol doing the redistribution for the other protocol to see it.

This is why a router that has an OSPF, EIGRP, and RIP interface needs the redistribution from each of the other two protocols in question. Neighboring devices will see the routes, but it can't be passed from OSPF -> EIGRP -> RIP on the same device.

-ryan

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of Joseph L. Brunner
Sent: Thursday, July 16, 2009 4:40 PM
To: Gary Duncanson; Joe Astorino
Cc: ccielab_at_groupstudy.com
Subject: RE: adverising loopback in OSPF Domain

Hi Gary,

One thing I learned a lot about redistribution from Sensei Brian and Brian's IE workbooks is that the redistribution goes on what is in the routing table, not the rib for the stated protocol;

So you will need to catch "redistributed connected" even if the router doing the redistribution is one side in Eigrp as 10, and the other side in OSPF Area 0.

Don't forget this very simple yet painful fact that can mess-up redistribution.

Just last night I found this on a router doing BGP<->Eigrp redistribution... There is always some talk about "interfaces included in the protocol are redistributed" automatically (I believe SM stated this in IE Proctor Guides in the past). I have seen the redistribution behavior where connected needed to be included.

Anyone else perhaps can clear this up better for Gary?

Thanks,

Joe

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of Gary Duncanson
Sent: Thursday, July 16, 2009 4:34 PM
To: Joe Astorino
Cc: ccielab_at_groupstudy.com
Subject: Re: adverising loopback in OSPF Domain

I recently did lab 8 in Ipexpert WB. It was the route redistribution
technology lab. One thing I noticed was there was a hell of a lot of
redistribute connected going on under just about every routing protocol
process across the piece. It wasn't an explicit requirement but it was
needed to get things working properly. Selective too using route-maps. I
know that there can be some fun when one is redistributing routes between
IGPs and connected routes are involved. Are there any tutorials on the ins
and outs of this?
----- Original Message -----
From: "Joe Astorino" <jastorino_at_ipexpert.com>
To: "Ryan West" <rwest_at_zyedge.com>
Cc: "Mohamed El Henawy" <m.henawy_at_link.net>; "Cisco certification"
<ccielab_at_groupstudy.com>
Sent: Thursday, July 16, 2009 5:54 PM
Subject: Re: adverising loopback in OSPF Domain

> Regarding your last question there -- I would just be very careful about
> which route you choose there. Make sure there are no underlying
> requirements that say you have to advertise certain routes into certain
> routing protocols, or a certain way. Be very cautious.
>
> On Thu, Jul 16, 2009 at 11:08 AM, Ryan West <rwest_at_zyedge.com> wrote:
>
>> Reachability information will be clearly defined on the lab. Most likely
>> you'll need all networks reachable while completing your IGP section.
>> This
>> might also be a good time to make your face known to the proctors for
>> clarification.
>>
>> -ryan
>>
>> -----Original Message-----
>> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
>> Mohamed El Henawy
>> Sent: Thursday, July 16, 2009 11:01 AM
>> To: Mohamed El Henawy; Cisco certification
>> Subject: Re: adverising loopback in OSPF Domain
>>
>> Thank you All for your replies..
>>
>> last question....during redistribution part if I found that there is
>> network
>> here or there need to be advertised...do I have to do it redistribute
>> connected and match the other interfaces in the routing table or I can
>> advertise it in any routing protocol running ?
>>
>>
>>
>> ----- Original Message -----
>> From: "Mohamed El Henawy" <m.henawy_at_link.net>
>> To: "Cisco certification" <ccielab_at_groupstudy.com>
>> Sent: Thursday, July 16, 2009 12:11 PM
>> Subject: adverising loopback in OSPF Domain
>>
>>
>> > Hello Group ,
>> >
>> > this might be silly question but its really bothering me
>> >
>> > when I'm asked to advertise "loopback in the OSPF Domain" do I have
>> > toe
>> > redistribute it or I can just advertise it in any OSPF Area on the
>> > router/switch ?
>> >
>> >
>> > Blogs and organic groups at http://www.ccie.net
>> >
>> > _______________________________________________________________________
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>>
>>
>>
>>
>>
>>
>>
>
>
> --
> Regards,
>
> Joe Astorino - CCIE #24347 R&S
> Technical Instructor - IPexpert, Inc.
> Cell: +1.586.212.6107
> Fax: +1.810.454.0130
> Mailto: jastorino_at_ipexpert.com
>
>
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Received on Thu Jul 16 2009 - 16:56:04 ART