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

[Rajesh Saluja]

Tony Przygienda wrote:


> > 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 )
> 
> L1 routers in 1195 don't have 130 TLVs. 130s are exclusively L2 in 1195. That's why you cannot mix L1 areas when updating!

Tony,
Thanks for your response. I just went through the draft that
you sent out on mailing list yesterday and it says that 
" If a deployment uses L1 external routes in an area that still
contains strictly RFC 1195 compliant routers, forwarding loops 
can easily be formed ".

This means that deployment of domain-wide draft needs changes in
the RFC1195 compliant routers. Only the L1 routers which understand
TLV 130 and accordingly understand internal/external routes and 
metric types need no upgrade. Is this correct?
Other than Cisco routers, are there other routers which support 
externals in L1?

This RFC1195 noncompliant behavior is not mentioned in any spec.
I thought that the one of the goals of this draft was not to
upgrade RFC 1195 compliant L1 routers which is not true anymore.



Thanks,
Rajesh