Sina,

>I don't really agree with your below statement ;-)

I was only agreeing with you that setting the forwarding address in a
Type 7 LSA may result in suboptimal routing. If the P-bit is set you
have to do it, whether you want to or not. Preferences for picking
forwarding addresses are discussed in the last paragraph of Section 3.3
of the NSSA draft.

If a type 7 LSA's P-bit is clear, you would only use a gateway address
as the LSA's forwarding address when it is part of the NSSA. Otherwise
you should just set the forwarding address to 0.0.0.0 as is done with
Type 5 LSAs. Neither RFC 1587 or the current draft state this
specifically. However, it shouldn't hurt to use a loopback address or a
stub network's ip address, provided they are part of the originating
NSSA.

As a general point, the non-zero forwarding address of a Type 5 LSA
should never be part of a stub or NSSA and the non-zero forwarding
address of a Type 7 LSA must always be part of the originating NSSA.
Setting them independently (except during translation) is always best.

>here is section 3.5 step 3 I don't see where it's stated

Sorry I should have referenced RFC 1587 Section 3.5 step 2.

         ... If the forwarding address is not 0.0.0.0,
         look up the forwarding address in the routing table. Packets
         routed to the external destination N will be routed within
         the NSSA to this forwarding address. An intra-area path
         must therefore exist to the forwarding address. If no such
         path exists, do nothing with the LSA and consider the next
         in the list.

Pat

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