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NSSA area-range command

‎07-08-2016 10:10 AM

Hello, 

I have a question regarding the difference between commands. 

 

For example, i setup a network with 3 areas. 

 

(area 1)<->(area 0)<>(area 2)

 

Area 1 = nssa area with an abr going to area 0. 

 

On area 1's abr i want to summarize the routes from the nssa area so that when it gets to area 2 they are condenced. 

 

So i would think this would be the command layout. 

 

root@area1-R4# show protocols ospf
area 0.0.0.1 {
nssa {
default-lsa {
default-metric 10;
metric-type 2;
type-7;
}
area-range 100.0.0.0/24;
}

 

But when i look at the abr bordering area 0 and area 2, and a router in area 2 i still only see all the smaller routes and not the summarized routes. 

 

But, if i move the area-range command to be directly under area 0.0.0.1 forinstance 

 

root@area1-R4# show protocols ospf
area 0.0.0.1 {
nssa {
default-lsa {
default-metric 10;
metric-type 2;
type-7;
}
}
area-range 100.0.0.0/24;

 

I see only the summarized route in the abr facing area 2 and all the routers in area 2 as well. 

Is there something i am missing, Could anyone help explain the difference between these two commands? 

 

set protocols ospf area 0.0.0.1 nssa area-range 100.0.0.0/24 

and
set protocols ospf area 0.0.0.1 area-range 100.0.0.0/24 

 

Thanks for any help. 

 

 

4 REPLIES 4
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Solution
Accepted by topic author robkuhn
‎08-01-2016 07:26 AM

Re: NSSA area-range command

[ Edited ]
‎07-08-2016 10:34 AM

set protocols ospf area 0.0.0.1 nssa area-range 100.0.0.0/24

 

Area range command under NSSA Stanza summarizes Type 7 LSA's before getting translated as Type 5 LSA's

 

set protocols ospf area 0.0.0.1 area-range 100.0.0.0/24

 

Area range command specified under area area-number stanza only summarizes intra-area prefixes

 

 

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Re: NSSA area-range command

‎07-08-2016 10:56 AM

So the behavior that was observed in your box is as per expectation (Inter-area prefixes got summarized after

area-range is configured under area area-number stanza.

 

area-range under nssa stanza is meant for only filtering Type 7 (external routes) for summarization

 

I dont have box now with me to cite illustration on the same.

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Re: NSSA area-range command

‎07-08-2016 07:51 PM

I treid it out on my lab and it worked the way you stated. I just couldn't find anything online that pointed out the difference. I think i was looking in the wrong areas online. 

 

I appreciate the help though, Saved me alot of digging around online. 

 

 

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Re: NSSA area-range command

[ Edited ]
‎07-08-2016 10:14 PM

 

Please Mark Message 2 as the Accepted Solution after unmarking Message 4,as the suggested solution worked as suggested in Message 2  and the same will benefit others who are referring the same

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