Re: Control redistribution: Route-map vs. distribute list

Hi Shaun,

Its not really a difference of route-map vs distribute-list; it's a matter
of your answer is wrong because you did not do what the task told you to do.

The first part said to redistribute EIGRP4 into EIGRP100. You did not do
that. You redistributed only a sub-set of the routes. As a proctor I would
validate that on R2 by doing a "show ip eigrp 100 topology" and looking for
the 24.234.0.0/24 routes. If they weren't there (regardless of your
commands used) you've failed the task.

The second part said to filter them into the rest of the domain. The two
main ways I can see to do this is a distribute-list, or a route-map applied
against a neighbor or neighbors. Personally, in the real-world, I'd prefer
the route-map myself, but in the lab, the distribute-list is quicker. The
route-map is a more long-term, maintainable configuration, but in the lab
we're not building real networks, we're doing what we're told. As a proctor
I'd use the same command above on other routers to validate. In this case
you're solution is working, but you can't get partial credit for a task.
 You did the first part wrong, so the whole thing is wrong.

I'd like to point out, however, that without knowing the topology of this
lab, I find their solution incomplete to the task. If R2 has only 1 path
into EIGRP100 (through Serial 0/0/0) then it's acceptable, but not knowing
this, I'd just put the distribute-list on, and not apply to a particular
interface. If a second link into EIGRP100 were brought up, they would allow
those routes out that way.

Remember, it's less a matter of "using the right commands", it's about
getting the right results without using forbidden commands. Most tasks
should be validated by checking results, not "show running".

On Mon, Oct 10, 2011 at 23:20, Shaun Gomez (4g1vn) <shaun.gomez_at_gmail.com>wrote:

> So here is the example.
>
> Redistribute EIGRP 4 into EIGRP 100 but, filter routes is 24.234.0.0/24 *
> range* from R2 into the rest of EIGRP 100 routing domain.
>
> Solution #1 (my first choice):
>
> Router eigrp 100
> Redistribute eigrp 4 route-map FILTER
>
> ip prefix-list FILTER seq 5 deny 24.234.0.0/24 le 32
> ip prefix-list FILTER seq 10 permit 0.0.0.0/0 le 32
> !
> route-map FILTER permit 10
> match ip address prefix-list FILTER
>
> Solution #2 (text book answer):
>
> router eigrp 100
> redistribute eigrp 4
> distribute-list 1 out serial 0/0/0
>
> access-list 1 deny 24.234.0.0 0.0.0.255
> access-list 1 permit any
>
> This issue I have with this is there are a bunch of 24.234.0.x/30 prefixes
> that are supposed to be blocked according to the "sh ip route eigrp"
> output.
>
>
> Your thoughts on distribute-list vs. route-map. This workbook is dated 2007
> so, it may be a little old as they are not using prefix lists in most
> examples.
>
> Thanks!
>
>
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Received on Tue Oct 11 2011 - 07:29:16 ART