[Isis-wg] Clarification needed on domain-wide prefix distribution

[Rajesh Saluja]

Tony Przygienda wrote:

> Let's steer the recent threads a little bit here:
> 
>   1. draft-ietf-isis-domain-wide  solves one single problem for deployments that don't have the need to migrate towards
>      TE extensions or don't want a "flag-day" solution but wnat to preserve 1195 compatibility.  So discussion about TE
>      draft and this draft are orthogonal.


For my understanding, can you verify if the following sentences 
are correct for domain-wide draft:

1. It needs changes only in L1L2 router. There is no change in L1
router implementation from RFC1195.

2. External routes are allowed in L1 domain. Which means that L1
routers can advertise external reachability information.

3. The external routes can only have internal metric type. 

4. In the given proposal, we can not distinguish 
between L1 externals from L2->L1 externals ( both will be 130:L1:I ) 
between L2 externals from L1->L2 externals (both will be 130:L2:I).


If 3 is correct, then why does the preference suggested in proposal
talks about L1:130:I and L1:130:E and same for L2.

If 3 is not correct (i.e. external routes in L1 domain can still have
internal
and external metric types) then it means that L1 routers should have the
capability to prefer internal metric types to external metric types and
according to RFC1195, they do not have this capability ( 3.10.1 )


Thanks,
Rajesh