[Isis-wg] integrated is-is question

[Mike Shand]

Looks wrong to me. Adjacencies must be adjacent! Is there some other 
context which makes this situation odd? Its not talking about who it shares 
LSPs with is it?

         Mike

At 14:41 17/11/1999 -0500, He, James wrote:

>To IS-IS fellows:
>
>I was reading the book "CCIE Professional Development: Routing TCP/IP,
>Volume 1" by Jeff Doyle from ciscopress.
>In the Integrated IS-IS chapter, there is an example which discusses IS-IS
>adjacency issues.
>The following is the illustration from the book:
>
>There are six L1/L2 routers in two areas, area1 and area2, and we assume
>area2 is a level 2 area (IS-IS backbone).
>The illustration is as follows:
>
>
>
>Subnet1--------R1---------------Subnet2-------------R2------------Subnet3
>                   |                                |
>                   |                                |
>                 R3                                        R4
>                   |                                |
>
>|---------------------------------------------------------------------------
>|
>                                 |
>                                 |
>                                    R5
>                                 |
>                                 |
>                   Subnet4-------------R6------------Subnet5
>
>
>
>The top section which consists of R1-R2-R3-R4 is area1 and the lower section
>which has R5-R6 constitutes area2.
>All routers are L1/L2 routers (the default configguration in cisco routers).
>
>On page 655 of the book,  it says that R6 will form level 1 adjacency with
>R5 as R5 is the only router in area2.
>However, R6 will form level 2 adjacency with every other router including R1
>to R4.
>
>Is this statement true? R6 is not physically connected to R1 or R2. How can
>it form level 2 adjacenct to them.
>Why can't R6 be level 1 adjacenct to R1 if we adopt the same logic.
>
>
>Many thanks in advance. Please forward answer to jameshe@ctron.com.
>
>
>James He
>
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