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RE: Mutual redistribution with route maps and tagging posted 01/16/2002
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That looks cool.  Gives me something else to play with tomorrow!

-----Original Message-----
From: nobody@xxxxxxxxxxxxxx [mailto:nobody@xxxxxxxxxxxxxx]On Behalf Of
Neil G. Legada
Sent: Tuesday, January 15, 2002 9:42 PM
To: cc13; Denise Donohue; ccielab@xxxxxxxxxxxxxx
Subject: Re: Mutual redistribution with route maps and tagging


Heres what I usually do when dealing with mutual redistribution when the
other IGP doesnt support route tagging. On cases when both IGP support route
tagging, Denise's config works fine:

1. On the redistributing router, issue a command 'sh ip route <igrp/rip>
(when running rip ver 1) and take note of the learned routes.
2. Form an ACL that permits those routes in 1 including the connected
subnets that igrp/rip is running between routers.
3. Form 2 route maps. 1st with 2 route-map entry: one that would deny
matching the ACL in 2 and the other that would permit anything (this will be
used on non-tag capable IGP). 2nd route-map: with only one entry that would
permit all the routes matching ACL in 2.
4. Do the necessary redistribution using the route-maps in 3.

Below are the sample configurations to make it a bit clearer:

R5#sh ip route igrp
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
       i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter
area
       * - candidate default, U - per-user static route, o - ODR
       P - periodic downloaded static route

Gateway of last resort is not set

I       150.10.4.0/24 [100/8976] via 150.10.40.4, 00:01:21, Serial0/0.3
I       150.10.45.0/24 [100/8576] via 150.10.40.4, 00:01:21, Serial0/0.3


router ospf 20
 redistribute igrp 20 metric-type 1 subnets route-map ONLY-IGRP
!
router igrp 20
 redistribute ospf 20 metric 1544 2000 255 1 1500 route-map NO-IGRP
 network 150.10.0.0

access-list 1 permit 150.10.4.0 0.0.0.255
access-list 1 permit 150.10.45.0 0.0.0.255
access-list 1 permit 150.10.40.0 0.0.0.255     *** IGRP is running on this
connected subnet

route-map NO-IGRP deny 10
 match ip address 1
!
route-map NO-IGRP permit 20
!
route-map ONLY-IGRP permit 10
 match ip address 1
!

NOTE: This is only good when IGRP learned routes are not that much that a
few hundred ACL lines are required. But as far as ccie lab practice is
concerned, its been useful in preventing route feedbacks.

Hope this helps.



Regards,
NGL CCIE#8576



----- Original Message -----
From: "cc13" <cc13@xxxxxxxxxxxxxxxx>
To: "Denise Donohue" <fradendon@xxxxxxxx>; <ccielab@xxxxxxxxxxxxxx>
Sent: Tuesday, January 15, 2002 11:42 PM
Subject: RE: Mutual redistribution with route maps and tagging


> I thought rip and igrp do not support tagging?
>
>
>
>
> -----Original Message-----
> From: nobody@xxxxxxxxxxxxxx [mailto:nobody@xxxxxxxxxxxxxx]On Behalf Of
> Denise Donohue
> Sent: Tuesday, January 15, 2002 9:41 AM
> To: ccielab@xxxxxxxxxxxxxx
> Subject: Mutual redistribution with route maps and tagging
>
>
> I saw what looks to me to be a simple and elegant solution to the
> redistribution problem of routers accepting back the routes they
originally
> advertised.  The solution involved creating a route map that tags the
> redistributed routes, and then denying routes with the process's own tag.
> Here is an example:
>
> route-map ospf2igrp deny 10
> match tag 2
> route-map ospf2igrp permit 20
> set tag 22
>
> route-map igrp2ospf deny 10
> match tag 22
> route-map igrp2ospf permit 20
> set tag 2
>
> router ospf 1
> red igrp 1 subnets route-map igrp2ospf metr xx
>
> router igrp 1
> red ospf 1 route-map ospf2igrp metr x x x x
>
> My question is: can anyone find a situation where this doesn't work?  I've
> used it for the past several days and it seems to work really well, but
> maybe some of you more imaginative people can point out any flaws in it's
> use!
> **Note: CCIE Security list is available.  For more information go to:
> http://www.groupstudy.com/list/security.html
> **Note: CCIE Security list is available.  For more information go to:
> http://www.groupstudy.com/list/security.html
**Note: CCIE Security list is available.  For more information go to:
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