Re: ospfv3 - Route Entry

Vivek Dubey <vivek_ospf@REDIFFMAIL.COM> Mon, 27 June 2005 07:05 UTC

MIME-Version: 1.0
Content-type: multipart/alternative; boundary="Next_1119855977---0-203.199.83.248-30201"
Message-ID: <20050627070617.30219.qmail@webmail36.rediffmail.com>
Date: Mon, 27 Jun 2005 07:06:17 -0000
Reply-To: Mailing List <OSPF@PEACH.EASE.LSOFT.COM>
Sender: Mailing List <OSPF@PEACH.EASE.LSOFT.COM>
From: Vivek Dubey <vivek_ospf@REDIFFMAIL.COM>
Subject: Re: ospfv3 - Route Entry
To: OSPF@PEACH.EASE.LSOFT.COM
Precedence: list

Hi Acee,
>Other implementations are possible. As you know, the OSPFv3 intra->area SPF calculation is done in 2 phases. First a Shortest Path Tree 
>(SPT) is built from the router and network LSAs. In the second phase, >the intra-area-prefix-LSAs are examined and routes are added to the >routing table for reachable prefixes based on whether the reference >LSA is reachable (among other checks). So, one either needs to lookup >the route to the corresponding node in the SPT or the reference LSA. >RFC 2740 chose the former and I think it is more straight forward.

Following from above:

draft-ietf-ospf-ospfv3-update-04
3.5.3  Installing LSAs in the database
----------------------------------------
Router-LSAs, Network-LSAs, Intra-Area-Prefix-LSAs, and Link-LSAs
      The entire routing table is recalculated, starting with the
      shortest path calculation for each area (see Section 3.8)

<vivek> Change in contents of "Intra-Area-Prefix-LSAs" does not require "entire routing table recalculation". Route entry for referenced router/transit link should be checked and best route to prefixes described in "Intra-Area-Prefix-LSAs" should be calculated

Thanks
Vivek





On Fri, 24 Jun 2005 Acee Lindem wrote :
>Vivek Dubey wrote:
>
>>Hi,
>>  
>Hi Vivek,
>
>>RFC 2328: Section 11
>>--------------------
>>Destination Type: Router entries are kept for area border routers and AS boundary routers
>>
>>draft-ietf-ospf-ospfv3-update-04
>>--------------------------------
>>Section 3.3  The Routing table Structure:
>>An entry for each router in the area is kept
>>
>><vivek> Calculation of reachability to stub networks and prefixes described in intra-area-prefix LSA is I guess similar. What's the need to maintain an entry for each router in the area ?
>>  
>Other implementations are possible. As you know, the OSPFv3 intra-area SPF
>calculation is done in 2 phases. First a Shortest Path Tree (SPT) is built from the
>router and network LSAs. In the second phase, the intra-area-prefix-LSAs are
>examined and routes are added to the routing table for reachable prefixes based
>on whether the reference LSA is reachable (among other checks). So, one either
>needs to lookup the route to the corresponding node in the SPT or the reference
>LSA. RFC 2740 chose the former and I think it is more straight forward.
>
>Thanks,
>Acee
>
>>Thanks
>>Vivek
>>
>>
>>
>>