Re: Type-7 to Type-5 translation issue

[sujay <sujayg at HUAWEI.COM>]

I guess the point is whether to defer the Type-7 to 5 conversion until
Type 5 expires, to save database size.

In case if the Type-7 carries a forwarding address, it should be
converted into the correct Type-5 without delay.

Best regds,
~Sujay

-----Original Message-----
From: Mailing List [mailto:OSPF at PEACH.EASE.LSOFT.COM] On Behalf Of
Santosh Esale
Sent: Saturday, May 14, 2005 8:41 PM
To: OSPF at PEACH.EASE.LSOFT.COM
Subject: Type-7 to Type-5 translation issue


Hi guys,
           Mine topology is as below-

R1----Area 1 ------R2--------Backbone Area------R3

Initially Area 1 was type-5 capabale area and i was redistributing RIP
routes into area 1 on R1, so R2 and R3 have type-5 LSAs for all the RIP
routes.Now i changed Area 1 to NSSA , So R1 is now orginating type-7
LSAs for all the RIP routes into area 1 with P-bit set.

Now mine question is should R2 -

 1.     Prefer type 7 LSA over type-5 .
Convert type-7 LSA into type-5 LSA  and flood into backbone, which
aleardy have  type-5 LSAs for the same netwroks earlier orginated by
R1(not yet flushed as it will remain in backbone for MAX AGE) (According
to RFC 3101. section 2.5 stp 6 (e) ).

Disadvantage: The LSP database size will be doubled till MAX AGE time.
Advantage : simplicity

2. Prefer type-5 over type-7 .
Use type-5 LSA for calculating external routes till type-5 LSAs
advertised by R1 exists in backbone(MAX Age) , and once type is flushed
because of MAX age , USE type -7 now to calculate external routes , and
translate at this point from type-7 to type-5(RFC 1587 3.5 step 5)

Advantage : LSP database size is small.
Disadvantage: bit complex,but not much.

3. or its Implementations Specific.

Thanks in Advance


-- 
Santosh Esale

Member - Technical Staff

Riverstone Networks India Pvt. Ltd.

Email: sesale at riverstonenet.com