Re: summary-address in ospf and redistribution

From: SherefMohamed@xxxxxxx
Date: Tue Jan 23 2001 - 12:55:22 GMT-3


   

You need to do mutual redistribution between OSPF and IGRP,
the idea is to not allow IGRP send back to OSPF the summary address !
Here is how I will do it:

!
router igrp 2
..........
distribute-list 10 out ospf
..........
!
router ospf 1
...........
distribute-list 11 out igrp
...........
!

access-list 10 deny 170.10.2.0 0.0.0.255
access-list 10 permit 0.0.0.0 255.255.255.255
!
access-list 11 permit 172.10.2.0 0.0.0.255
access-list 11 deny 0.0.0.0 255.255.255.255

Please test it & tell me how it works !

Thanks
Sheref

                    "Connary,

                    Julie Ann" To: ccielab@groupstudy.com

                    <jconnary@cis cc:

                    co.com> Subject: summary-address in ospf a
nd redistribution
                    Sent by:

                    nobody@groups

                    tudy.com

                    01/23/2001

                    08:37 AM

                    Please

                    respond to

                    "Connary,

                    Julie Ann"

Hi All,

I ran across a practice lab and another fat-kid lab that use the ospf
summary-address to overcome
vlsm to fsm issues when redistributing ospf into igrp:

situation: The ospf connected interface has a longer mask than the IGRP
connected interface.
                     area-range does not work because it is on the same
router.

             The Fatkid lab - expert redistribution - solves this with a
summary-address.

Question - does this not inject E2 routes back into your OSPF domain?

OSPF area 2
170.10.128.4 - 255.255.255.192
|
|
|
R4 -----------IGRP - 170.10.2.4 255.255.255.0

To redistribute the ospf interface into IGRP a summary-address is
used: summary-address 170.10.128.0 255.255.255.0

But then in the ospf domain you get an E2 route to 170.10.128.0 in your
ospf domain.

So how do you prevent this E2 route into OSPF - can you filter it?

Thoughts?

remember - no static, no default.

Julie Ann

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                                         Julie Ann Connary
           | | Network Consulting Engineer
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