Re: OSPF and BGP query

OSPF NSSA will only convert a route redistributed into the NSSA as a type
7. For External routes (type 5) received within OSPF it just filters these.
It won't generate a default route unless you specify area x nssa
default-information originate. So in your scenario R1 would have
no reach-ability to the redistributed rip route.

When a router originates a BGP route configured with a *network *router
configuration command or through route redistribution (*redistribute *router
configuration command), it sets the BGP next hop to the IGP next hop (the
same value youd find in the IP routing table). BGP next hop is set to
0.0.0.0 for routes with unknown next hops  connected interfaces, static
routes to *null 0 *or summary routes configured with *aggregate-address
*router
configuration command.

Hope that helps,

Marc

On Mon, Jul 30, 2012 at 10:18 AM, Routing Freak
<routingfreak_at_gmail.com>wrote:

> Hi all
>
> I have a set up like this
>
>
> R1---------R2----------R3----------R4------R5
>
>
>
> R1------R2===NSSA Area 1
>
> R2--------R3====Backbone Area 0
>
>
> R3------------R4 ===== Normal area 2
>
>
>
> R4---------R5======== RIP
>
>
> I am redistributing RIP routes on R4 into OSPF .. Whether R2 will convert
> this into Type 7 LSA and send it to the NSSA Area or else it will generate
> default route.
> because Type 5 LSA are not allowed in NSSA Area..
>
>
>
> 2.. BGP Scenario
>
>
> R1----------R2------------R3--------------R4
>
> R1---------R2 ==== OSPF
>
> R2----------R3 ===== EBGP . R2 is in AS 10 , R3 is in AS 20
>
> R3-----------R4 ======EBGP R4 is in AS 30
>
>
> When R2 is redistributing OSPF routes into BGP, what will be next hop found
> in R3 , it is the R2 neighbor address or else the IGP next hop to the OSPF
> route.
>
> Bit confused with this logic.
>
> Thanks in advance,
>
>
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--
Marc Abel
CCIE #35470
(Routing and Switching)
Blogs and organic groups at http://www.ccie.net