RE: Has Redistribution Behavior Changed Or Am I High?

From: Scott M Vermillion (scott@it-ag.com)
Date: Sat Dec 22 2007 - 02:47:47 ART

Hi Kim,

Just to clarify, there was a separate task to redistribute my Lo0 into OSPF
early on in the lab (and the task requirement can only be met via
redistribution - a network statement or 'ip ospf 100 area 0' at the
interface level are both expressly prohibited). Then, separately, at the
end of the IGP section, I'm to redistribute OSPF into RIP and RIP into OSPF.
In the SG, they have 'redistribute connected' under the RIP process. A
brief mention is made in the lab breakdown video that this is because of the
earlier redistribution of connected into OSPF. However, I find no apparent
difference in any routing table regardless of this commands presence or
absence under RIP. Of course, it's been a long day and I haven't been
focused at all since I started out this morning. So maybe a good night's
sleep will help. Also, I'll try to navigate back to that section of the IE
ATC CoD. I remember this being discussed at length but I apparently don't
yet have it all committed to memory.

 

Thanks much,

Scott

 

 

From: Kim teu [mailto:kim.teu@gmail.com]
Sent: Friday, December 21, 2007 10:41 PM
To: Scott M Vermillion
Cc: ccielab@groupstudy.com
Subject: Re: Has Redistribution Behavior Changed Or Am I High?

 

Scott,

The "redistribute connec route-map LOOPBACK_ONLY" should be under RIP
process, not OSPF process. Then, when you redistribute ospf under RIP, only
loopback interface get redistributed, but not other OSPF enabled interfaces.

 

HTH,

Kim

 

 

 

On 12/21/07, Scott M Vermillion <scott@it-ag.com> wrote:

OK folks, admittedly a soft spot in my underbelly here.

Redistribution rules as I have come to understand them (not necessarily in
any kind of order):

--redistribute any routes learned from the protocol being redistributed

--redistribute any connected interfaces that are covered by network
statement under the protocol being redistributed

--however, if a 'redistribute connected' statement exists in the protocol
being redistributed, only redistribute those connected interfaces which are
allowed in the manual 'redistribute connected' statement

So, for example, if I have router R1 running both RIP and OSPF, and I have
redistributed my loopback interface into OSPF with a route-map permitting
*only* the loopback to go into OSPF, then if I then later redistribute OSPF
into RIP, I will get all routes learned by OSPF in RIP but I will not get
the networks of directly connected links/interfaces running OSPF, because my
route-map didn't encompass anything but the loopback interface.

I thought I finally understood this concept correctly. Do I?

Because in my lab, I'm not seeing this. I have the exact scenario above
configured. In a Solutions Guide, it shows doing a 'redistribute connected'

under the RIP process, presumably in an effort to pull in directly connected
non-RIP/OSPF networks as well as those *learned* by OSPF. Right? Or wrong?
Because I am observing zero difference whether this manual redistribution of

connected exists under the RIP process or not. I do in fact seem to get the
directly connected non-RIP/OSPF networks showing up in and being advertised
into RIP, even sans a manual redistribution of connected under RIP.

So I ask you once again, am I on something good? Are my pupils perhaps a
little dilated this evening? Please advise.

Regards all,

Scott

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