From: SherefMohamed@xxxxxxx
Date: Tue Jan 23 2001 - 17:41:17 GMT-3
The whole trick here is that IGRP & OSPF shares the same default class B
address (172.10.x.x), that's why
I don't think split-horizon will help you better in this situation !
"Robert DeVito"
<robertdevito@ho To: SherefMohamed@cdh.org, jcon
nary@cisco.com
tmail.com> cc: ccielab@groupstudy.com, nob
ody@groupstudy.com
Sent by: Subject: Re: summary-address in
ospf and redistribution
nobody@groupstud
y.com
01/23/2001 01:41
PM
Please respond
to "Robert
DeVito"
Shouldn't split-horizon take care of the problem of IGRP advertising OSPF
routes back into OSPF?
Robert
----Original Message Follows----
From: SherefMohamed@cdh.org
Reply-To: SherefMohamed@cdh.org
To: "Connary, Julie Ann" <jconnary@cisco.com>
CC: ccielab@groupstudy.com, nobody@groupstudy.com
Subject: Re: summary-address in ospf and redistribution
Date: Tue, 23 Jan 2001 09:55:22 -0600
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 and 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
------------------------------------------------------------------------
Julie Ann Connary
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