Re: Ospf redistrib into eigrp - 2 locations

Ah, now I see some things I missed before.

First, couple of global thing: EIGRP only carries one type of external
routes, like OSPF's E1, so internal EIGRP cost does change the initial
cost at redistribution point (cost seed). But there is no dynamic
translation of original cost (OSPF) into EIGRP metrics, so it does not
matter how good/bad OSPF metrics were at the redistribution points.

Now, when R1 shows the route to R3, now R3 has 2 competing sources for
this network: OSPF and EIGRP. Do metrics matter ? At a different level,
because you can not compare OSPF's with EIGRP's. So administrative
distance is used and EIGRP wins. Now, R3's initial metric is larger
(and if you have split horizon, it won't even tell to R2).

-Carlos

Aaron @ 06/03/2011 02:23 -0300 dixit:
> Thanks Carlos, That might be, however it didn't exactly seem that way in
> what I saw...
>
> Router 1 and 3 where the two routers redistributing ospf into
> eigrp.....router 2 was the one router solely running eigrp. Router 1, 3 and
> 2 share a vlan with one another.
>
> if I didn't tell you before, router 1 and 3 are both connected to the same
> WAN/OSPF side...learning much the same routes as each other....so point is
> that they should be redis'ing the same set of routes into eigrp to that
> router 2 that I mention. Also, I'm running a route-map upon redis at router
> 1 and 3 and setting same metrics to be fed into eigrp to router 2.
>
> When I redistributed from both routers 1 and 3 simultaneously I wanted to
> see dual equal cost routes in router 2. I didn't. so, I removed
> redistribution on router 1....then looked at router 2's metric for a route
> learned via router 3. Say it was 12345678. Then I removed redis from
> router 3 and enabled redis on router 1....then looked at router 2's metric
> for a route learned via router 1. Say it was 12345678. ...point is, it
> seems that when singularly redis'ing from 1 or 3, 2 sees same metric.
> That's why it didn't appear that the network router 2 was seeing was further
> away (metrically) via 1 compared to 3 or vice versa.
>
> I'm still undergoing my learning in the area of redistributing routing info
> in such a way that it could be back-fed via another router on same LAN
> segment (BMA) or NBMA network perhaps which is connected back into the area
> of the network that the redis'ing router is....so I don't know the details
> enough to appreciate what exactly was going on, but it would seem that you
> wouldn't want router 1 to send routes to router 3 or vice versa that they
> already know about since they are both connected to the same WAN..... with
> that in mind, I did the following to filter out route info on router 1 and 3
> so they wouldn't learn anything from each other, but still be able to redis
> their ospf info into the vlan shared with router 2....
>
> "distribute-list in f1/1" on router 1 and 3. F1/1 is the interface on both
> of those that connects to the vlan that they both share with router 2.
>
> Now router 2 sees equal cost routes.
>
> I don't really know why not having a distribute list filtering out route
> info from router 1 and 3 would've caused router 2 to NOT have the dual equal
> cost routes.....but this fixed it.
>
>
> Aaron
>
>
> -----Original Message-----
> From: Carlos G Mendioroz [mailto:tron_at_huapi.ba.ar]
> Sent: Saturday, March 05, 2011 11:57 AM
> To: Aaron
> Cc: ccielab_at_groupstudy.com
> Subject: Re: Ospf redistrib into eigrp - 2 locations
>
> Cause the distance from that router to the redistribution places is
> different ?
>
> -Carlos
>
> Aaron @ 05/03/2011 13:36 -0300 dixit:
>> I'm trying to redistrib ospf into eigrp at 2 locations; and at those 2
> locations i set metrics to be 1 1 1 1 1
>> There is a third router in the eigrp AS , purely eigrp. Wondering why
> that third router is not seeing 2 equal cost routes in its routing table
> (rib) from each of my 2 redistrib locations.?
>> Aaron
>>
>>
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-- 
Carlos G Mendioroz  <tron_at_huapi.ba.ar>  LW7 EQI  Argentina
Blogs and organic groups at http://www.ccie.net