Subject: FW: Regarding RFC 1765 OSPF Database Overflow

From: Naresh Paliwal <[email-masked]>
Date: Thu, 2 Sep 2004 17:51:46 +0530

Its said in the RFC that "Parameter, ospfExtLsdbLimit, must be the same
in all routers in the routing domain."

Same time we discuss a case of receiving a new AS-External-LSA which
causes
to hit the limiting parameter.

If the parameter, ospfExtLsdbLimit, is same on all the routers, such an
LSA
will never be generated. The originating router itself will hit the
limit,
and will enter in OverflowSate.

Please let me know if my understanding is wrong. Why should we implement
this case (the receiving of N'th AS-External-LSA).

Regards

- Naresh Paliwal

Nevis Networks Pvt Ltd

www.nevisnetworks.com

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From: Dilip Kumar <[email-masked]>
Date: Thu, 2 Sep 2004 10:24:01 -0700

Self-Originated AS-External LSAs are not accounted for while comparing
with the ospfExtLsdbLimit. ospfExtLsdbLimit is compared with total
number of AS-Ext LSAs generated by other routers in OSPF domain.

-- Dilip

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From: Ehsan Rezaaifar <[email-masked]>
Date: Thu, 2 Sep 2004 14:06:39 -0400

> number of AS-Ext LSAs generated by other routers in OSPF domain.

That's not correct. The total number of non-default AS-External LSAs
(including
the self originated ones) should not exceed the ospfExtLsdbLimit (Sec. 2.2 in
RFC).
If the ospfExtLsdbLimit parameter is the same in all routers the router
originating the
external LSA is the one going into overflow mode. But during LSDB convergence
it's
possible to receive type 5 LSAs causing a router going to overflow mode as
described in
sec. 2.3.1 of the RFC.

Take care,
Ehsan