[j-nsp] ISIS-OSPF Redistribution Questions

[Walaa Abdel razzak]

Hi 

Yeah, the toppolgy is like the book. and I was thinking that static will be the only optimal one. many thanks for replying me.

Best Regards,
Walaa Abdel Razzak

-----Original Message-----
From: Hoogen [mailto:hoogen82 at gmail.com]
Sent: Sun 08/11/2009 13:31
To: Walaa Abdel razzak
Cc: juniper-nsp at puck.nether.net
Subject: Re: [j-nsp] ISIS-OSPF Redistribution Questions
 
It's late night here... excuse my typos and all the gibberish.. But yeah
Static routes maybe the only solution..

-Hoogen

On Sun, Nov 8, 2009 at 2:29 AM, Hoogen <hoogen82 at gmail.com> wrote:

> What is your topology?.. Is your topology is similar to the book?? The
> questions do seem a bit awkward... Well yeah NSSA def route is like an
> external route so changing the value affects everything... and for ISIS
> level 1 preference can be set specifically and def route generated by ISIS
> (Book Case Study) is level 1.
>
> Thinking about it... The only way you can do things is using preference
> values.. since OSPF nor ISIS can have an import policy. So in this scenario
> of yours you might not have optimal routing.. It is a loop..if you do have
> to put that level 1 external preference as 149...
>
> Another way to just solve your problem would be to have static routes... to
> the ABR's.
>
> -Hoogen
>
>
> On Sun, Nov 8, 2009 at 12:38 AM, Walaa Abdel razzak <walaaez at bmc.com.sa>wrote:
>
>>  Hi
>>
>> If I did this, then R6 or R7 will prefer datacenter routes through R5 bcoz
>> they r coming with lower preference than ISIS routes which make sub-optimal
>> routing.
>>
>>
>> Best Regards,
>> Walaa Abdel Razzak
>>
>>
>> -----Original Message-----
>> From: Hoogen [mailto:hoogen82 at gmail.com <hoogen82 at gmail.com>]
>> Sent: Sat 07/11/2009 22:38
>> To: Walaa Abdel razzak
>> Cc: juniper-nsp at puck.nether.net
>> Subject: Re: [j-nsp] ISIS-OSPF Redistribution Questions
>>
>> Hi,
>>
>> Your scenario looks like a complete opposite of what we have in the case
>> study, from what you have mentioned here.. The solution would be that on
>> R6
>> and R7 you set the ospf external-preference to be lower than 149.. This
>> would make the def route from OSPF more preferred.
>>
>> set protocols ospf external-preference 148 <-- Make the nssa def route
>> preference on R6 and R7 to be lower than that received from the ISIS DC
>> router.
>>
>> -Hoogen
>>
>> 2009/11/7 Walaa Abdel razzak <walaaez at bmc.com.sa>
>>
>> > Hi Experts
>> >
>> >
>> >
>> > If you have area 2 nssa receiving default route from the ABR with metric
>> > 150, two routers R6, R7 are sending this default route to ISIS level 1
>> > router in the DC. The L1 external preference are modified on R6, R7 to
>> be
>> > 149. This is to prefer routes coming from ISIS than OSPF. The problem is
>> > that DC router resend the default route from R6 to R7. R7 see it with
>> > preference of 149 and the default route is coming from OSPF is 150 so it
>> > prefers the ISIS which cause non-optimal routing. Any ideas to solve
>> this
>> > issue without making modification on the DC router?
>> >
>> >
>> >
>> > Sample config:
>> >
>> >
>> >
>> > R6 or R7 config.:
>> >
>> > --------------------
>> >
>> > isis {
>> >
>> >    export senddefault;           --------à send default to the ISIS
>> router
>> >
>> >    level 2 disable;
>> >
>> >    level 1 external-preference 149;
>> >
>> >    interface fe-1/3/1.23;
>> >
>> >    interface lo0.6;
>> >
>> > }
>> >
>> > ospf {
>> >
>> >    export fromisis;                 --------à redistribute routes from
>> ISIS
>> >
>> >    area 0.0.0.2 {
>> >
>> >        nssa;
>> >
>> >        interface lo0.6;
>> >
>> >        interface fe-1/3/0.20;
>> >
>> >        interface fe-1/3/1.16;
>> >
>> >        interface fe-1/3/1.23 {
>> >
>> >            passive;
>> >
>> >        }
>> >
>> >    }
>> >
>> > }
>> >
>> >
>> >
>> > DC:
>> >
>> > -----
>> >
>> > isis {
>> >
>> >    export static-isis;
>> >
>> >    level 2 disable;
>> >
>> >    interface fe-1/3/0.23;
>> >
>> >    interface fe-1/3/0.24;
>> >
>> > }
>> >
>> >
>> >
>> > BR,
>> >
>> > Walaa Abdel Razzak
>> >
>> > _______________________________________________
>> > juniper-nsp mailing list juniper-nsp at puck.nether.net
>> > https://puck.nether.net/mailman/listinfo/juniper-nsp
>>
>>
>